INTERPOLATING RELATIVE HUMIDITY W EIGHTING FACTORS … RH.pdf · INTERPOLATING RELATIVE HUMIDITY W...

INTERPOLATING RELATIVE HUMIDITY WEIGHTING FACTORSTO CALCULATE VISIBILITY IMPAIRMENT AND

THE EFFECTS OF IMPROVE MONITOR OUTLIERS

August 30, 2001

Submitted to:

U.S. Environmental Protection AgencyOff ice of Air Quali ty Planning and Standards

Research Triangle Park, NC 27711

Submitted by:

Science Applications International Corporation615 Oberlin Road, Suite 100

Raleigh, NC 27605

EPA Contract No. 68-D-98-113, WA No. 3-39SAIC Project No. 01-0825-08-3999-XXX

i

TABLE OF CONTENTS

List of Figures................................................................................................................................ ii

List of Tables ................................................................................................................................. v

1. INTRODUCTION................................................................ ................................ ................................ .......... 1-1

2. DATASETS FOR CALCULATING VISIBILITY IMPAIRMENT ......................................................... 2-1

2.1 METHODOLOGY ........................................................................................................................................2-12.2 RESULTS AND DISCUSSION....................................................................................................................2-82.3 CONCLUSIONS.........................................................................................................................................2-332.4 REFERENCES............................................................................................................................................2-33

3. CLASS I AREA CLUSTER ANALYSES BASED ON MONTHLY AVERAGE F(RH) VALUES....... 3-1

4. OUTLIERS AND THEIR EFFECTS ON AVERAGE VISIBILITY IMPAIRMENT CONDITIONS . 4-1

4.1 OUTLIER ANALYSIS METHODOLOGY ..............................................................................................................4-14.2 INFORMATION ON THE INDIVIDUAL SITES AND YEARS ....................................................................................4-34.3 DISCUSSION OF DATA DISTRIBUTION .............................................................................................................4-44.4 EFFECT OF OUTLIERS ON AVERAGES..............................................................................................................4-84.5 CONCLUSIONS ..............................................................................................................................................4-12

APPENDIX A. ................................ ................................ ................................ ................................ ..................... A-1

APPENDIX B. ................................ ................................ ................................ ................................ ......................B-1

APPENDIX C. ................................ ................................ ................................ ................................ ......................B-2

ii

LIST OF FIGURES

Figure 1-1. Weighting Factor Curve for the Hygroscopicity of Sulfates and Nitrates...........1-2Figure 2-1. Cumulative Probabili ty of Hourly Relative Humidity Values at NWS

Stations.................................................................................................................2-2Figure 2-2. Cumulative Probabili ty of Hourly Relative Humidity Values at

IMPROVE Stations..............................................................................................2-3Figure 2-3. Distribution of Daily f(RH) Values about the Monthly Averages.......................2-3Figure 2-4. Agreement Between Monthly Average f(RH) Values and Interpolated

Values for the Same Sites....................................................................................2-5Figure 2-5. Relative Humidity Monitors Near Isle Royale National Park .............................2-7Figure 2-6. Relative Humidity Monitors Near Shenandoah National Park............................2-7Figure 2-7. Monthly Average f(RH) Values for January (all weather stations shown) .........2-9Figure 2-8. Monthly Average f(RH) Values for February (all weather stations shown) .....2-10Figure 2-9. Monthly Average f(RH) Values for March (all weather stations shown) .........2-11Figure 2-10. Monthly Average f(RH) Values for April (all weather stations shown) ...........2-12Figure 2-11. Monthly Average f(RH) Values for May (all weather stations shown).............2-13Figure 2-12. Monthly Average f(RH) Values for June (all weather stations shown).............2-14Figure 2-13. Monthly Average f(RH) Values for July (all weather stations shown) .............2-15Figure 2-14. Monthly Average f(RH) Values for August (all weather stations shown) ........2-16Figure 2-15. Monthly Average f(RH) Values for September (all weather stations shown)...2-17Figure 2-16. Monthly Average f(RH) Values for October (all weather stations shown) .......2-18Figure 2-17. Monthly Average f(RH) Values for November (all weather stations shown) ...2-19Figure 2-18. Monthly Average f(RH) Values for December (all weather stations shown) ...2-20Figure 2-19. Monthly Average f(RH) Values for January......................................................2-21Figure 2-20. Monthly Average f(RH) Values for February....................................................2-22Figure 2-21. Monthly Average f(RH) Values for March .......................................................2-23Figure 2-22. Monthly Average f(RH) Values for April .........................................................2-24Figure 2-23. Monthly Average f(RH) Values for May...........................................................2-25Figure 2-24. Monthly Average f(RH) Values for June...........................................................2-26Figure 2-25. Monthly Average f(RH) Values for July ...........................................................2-27Figure 2-26. Monthly Average f(RH) Values for August ......................................................2-28Figure 2-27. Monthly Average f(RH) Values for September.................................................2-29Figure 2-28. Monthly Average f(RH) Values for October .....................................................2-30Figure 2-29. Monthly Average f(RH) Values for November .................................................2-31Figure 2-30. Monthly Average f(RH) Values for December ................................................2-32Figure 3-1. IMPROVE Cluster 74 and Nearby Class I Areas................................................3-7Figure 3-2. IMPROVE Cluster 76 and Nearby Class I Areas................................................3-8Figure 3-3. IMPROVE Clusters 86 and 87 and Nearby Class I Areas...................................3-9Figure 3-4. IMPROVE Cluster 93 and Nearby Class I Areas..............................................3-10Figure 3-5. IMPROVE Clusters 96, 97, and 98....................................................................3-11Figure 4-1. Occurrence of Outliers at IMPROVE Sites: 1994-1998, Best Days ..................4-7Figure 4-2. Occurrence of Outliers at IMPROVE Sites: 1994-1998, Worst Days................4-7Figure 4-3. Effect of Values Outside 2σ on Average Visibili ty Impairment at

IMPROVE Sites: 1994-1998, Best Days..........................................................4-10

iii

LIST OF FIGURES (continued)

Figure 4-4. Effect of Values Outside 3σ on Average Visibili ty Impairment atIMPROVE Sites: 1994-1998............................................................................4-10

Figure 4-5. Effect of Values Outside 2σ on Average Visibili ty Impairment atIMPROVE Sites: 1994-1998, Worst Days.......................................................4-11

Figure 4-6. Effect of Values Outside 3σ on Average Visibili ty Impairment atIMPROVE Sites: 1994-1998, Worst Days.......................................................4-11

Figure A-1. Data Distribution from Acadia IMPROVE Monitor (Deciviews),1994-1998...........................................................................................................A-2

Figure A-2. Data Distribution from Acadia IMPROVE Monitor (Light Extinction),1994-1998...........................................................................................................A-2

Figure A-3. Data Distribution from Bandelier IMPROVE Monitor (Deciviews),1994-1998...........................................................................................................A-3

Figure A-4. Data Distribution from Bandelier IMPROVE Monitor (Light Extinction),1994-1998...........................................................................................................A-3

Figure A-5. Data Distribution from Big Bend IMPROVE Monitor (Deciviews),1994-1998...........................................................................................................A-4

Figure A-6. Data Distribution from Big Bend IMPROVE Monitor (Light Extinction),1994-1998...........................................................................................................A-4

Figure A-7. Data Distribution from Chiricahua IMPROVE Monitor (Deciviews),1994-1998...........................................................................................................A-5

Figure A-8. Data Distribution from Chiricahua IMPROVE Monitor (Light Extinction),1994-1998...........................................................................................................A-5

Figure A-9. Data Distribution from Crater Lake IMPROVE Monitor (Deciviews),1994-1998...........................................................................................................A-6

Figure A-10. Data Distribution from Crater Lake IMPROVE Monitor (Light Extinction),1994-1998...........................................................................................................A-6

Figure A-11. Data Distribution from Denali IMPROVE Monitor (Deciviews),1994-1998...........................................................................................................A-7

Figure A-12. Data Distribution from Denali IMPROVE Monitor (Light Extinction),1994-1998...........................................................................................................A-7

Figure A-13. Data Distribution from Dolly Sods IMPROVE Monitor (Deciviews),1994-1998...........................................................................................................A-8

Figure A-14. Data Distribution from Dolly Sods IMPROVE Monitor (Light Extinction),1994-1998...........................................................................................................A-8

Figure A-15. Data Distribution from Great Sand Dunes IMPROVE Monitor(Deciviews), 1994-1998......................................................................................A-9

Figure A-16. Data Distribution from Great Sand Dunes IMPROVE Monitor(Light Extinction), 1994-1998............................................................................A-9

Figure A-17. Data Distribution from Great Smoky Mountains IMPROVE Monitor(Deciviews), 1994-1998......................................................................................A-9

Figure A-18. Data Distribution from Great Smoky Mountains IMPROVE Monitor(Light Extinction), 1994-1998..........................................................................A-10

Figure A-19. Data Distribution from Point Reyes IMPROVE Monitor (Deciviews),1994-1998.........................................................................................................A-10

iv

LIST OF FIGURES (continued)

Figure A-20. Data Distribution from Point Reyes IMPROVE Monitor(Light Extinction), 1994-1998..........................................................................A-11

Figure C-1. Effect of Outliers at Acadia IMPROVE Monitor for 2σ range(Deciviews) ..........................................................................................................C-2

Figure C-2. Effect of Outliers at Acadia IMPROVE Monitor for 2σ range(Light Extinction).................................................................................................C-2

Figure C-3. Effects of Outliers at Bandelier IMPROVE Monitor for 2σ range(Deciviews) ..........................................................................................................C-5

Figure C-4. Effect of Outliers at Bandelier IMPROVE Monitor for 2σ range(Light Extinction).................................................................................................C-5

Figure C-5. Effect of Outliers at Big Bend IMPROVE Monitor for 2σ range(Deciviews) ..........................................................................................................C-8

Figure C-6. Effect of Outliers at Big Bend IMPROVE Monitor for 2σ range(Light Extinction).................................................................................................C-8

Figure C-7. Effect of Outliers at Chiricahua IMPROVE Monitor for 2σ range(Deciviews) ........................................................................................................C-11

Figure C-8. Effect of Outliers at Chiricahua IMPROVE Monitor for 2σ range(Light Extinction)...............................................................................................C-11

Figure C-9. Effect of Outliers at Crater Lake IMPROVE Monitor for 2σ range(Deciviews) ........................................................................................................C-14

Figure C-10. Effect of Outliers at Crater Lake IMPROVE Monitor for 2σ range(Light Extinction)...............................................................................................C-14

Figure C-11. (Effect of Outliers at Denali IMPROVE Monitor for 2σ range(Deciviews) ........................................................................................................C-17

Figure C-12. Effect of Outliers at Denali IMPROVE Monitor for 2σ range(Light Extinction)...............................................................................................C-17

Figure C-13. Effect of Outliers at Dolly Sods IMPROVE Monitor for 2σ range(Deciviews) ........................................................................................................C-20

Figure C-14. Effect of Outliers at Dolly Sods IMPROVE Monitor for 2σ range(Light Extinction)...............................................................................................C-20

Figure C-15. Effect of Outliers at Great Sand Dunes IMPROVE Monitor for 2σ range(Deciviews) ........................................................................................................C-23

Figure C-16. Effect of Outliers at Great Sand Dunes IMPROVE Monitor for 2σ range(Light Extinction)...............................................................................................C-23

Figure C-17. Effect of Outliers at Great Smoky Mountains IMPROVE Monitor for2σ range (Deciviews).........................................................................................C-26

Figure C-18. Effect of Outliers at Great Smoky Mountains IMPROVE Monitor for2σ range (Light Extinction) ...............................................................................C-26

Figure C-19. Effect of Outliers at Point Reyes IMPROVE Monitor for 2σ range(Deciviews) ........................................................................................................C-29

Figure C-20. Effect of Outliers at Point Reyes IMPROVE Monitor for 2σ range(Light Extinction)...............................................................................................C-29

v

LIST OF TABLES

Table 2-1. Agreement Between Measured and Interpolated Monthly Average f(RH)Values at IMPROVE Sites...................................................................................2-6

Table 3-1. Monthly Average Relative Humidity Weighting Factors, f(RH), forMandatory Class I Areas Listed by Cluster .........................................................3-2

Table 4-1. IMPROVE Sites Investigated for Outlier Effects................................................4-2Table 4-2. Statistical Summary for the 1994-1998 Visibili ty Impairment Data...................4-4Table 4-3. Occurrence of Outliers at All Ten Sites for Various Outlier Cutoff Ranges.......4-5Table 4-4. Extreme Outliers for the Worst Days Data Sets from 1994-1998.......................4-6Table 4-5. Effect of Visibili ty Units on the Number of Outliers ..........................................4-8Table 4-6. Effect of Outliers of Average Visibili ty Impairment at IMPROVE Sites,

1994-1998............................................................................................................4-9Table B-1. 1994-1998 Summary Data for the Best Days (Deciviews)..................................B-2Table B-2. 1994-1998 Summary Data for Best Days (Light Extinction) ..............................B-3Table B-3. 1994-1998 Summary Data for Worst Days (Deciviews).....................................B-4Table B-4. 1994-1998 Summary Data for Worst Days (Light Extinction) ...........................B-5Table C-1. Visibili ty Data for Acadia IMPROVE Monitor (Deciview)................................C-3Table C-2. Visibili ty Data for Acadia IMPROVE Monitor (Light Extinction).....................C-4Table C-3. Visibili ty Data for Bandelier IMPROVE Monitor (Deciview)............................C-6Table C-4. Visibili ty Data for Bandelier IMPROVE Monitor (Light Extinction).................C-7Table C-5. Visibili ty Data for Big Bend IMPROVE Monitor (Deciviews). .........................C-9Table C-6. Visibili ty Data for Big Bend IMPROVE Monitor (Light Extinction)...............C-10Table C-7. Visibili ty Data for Chiricahua IMPROVE Monitor (Deciviews) ......................C-12Table C-8. Visibili ty Data for Chiricahua IMPROVE Monitor (Light Extinction).............C-13Table C-9. Visibili ty Data for Crater Lake IMPROVE Monitor (Deciviews).....................C-15Table C-10. Visibili ty Data for Crater Lake IMPROVE Monitor (Light Extinction) ...........C-16Table C-11. Visibili ty Data for Denali IMPROVE Monitor (Deciviews).............................C-18Table C-12. Visibili ty Data for Denali IMPROVE Monitor (Light Extinction) ...................C-19Table C-13. Visibili ty Data for Dolly Sods IMPROVE Monitor (Deciviews)......................C-21Table C-14. Visibili ty Data for Dolly Sods IMPROVE Monitor (Light Extinction) ............C-22Table C-15. Visibili ty Data for Great Sand Dunes IMPROVE Monitor (Deciviews) ..........C-24Table C-16. Visibili ty Data for Great Sand Dunes IMPROVE Monitor

(Light Extinction)...............................................................................................C-25Table C-17. Visibili ty Data for Great Smoky Mountains IMPROVE Monitor

(Deciviews) ........................................................................................................C-27Table C-18. Visibili ty Data for Great Smoky Mountains IMPROVE Monitor

(Light Extinction)...............................................................................................C-28Table C-19. Visibili ty Data for Point Reyes IMPROVE Monitor (Deciviews) ....................C-30Table C-20. Visibili ty Data for Point Reyes IMPROVE Monitor (Light Extinction)...........C-31

1 - 1

1. INTRODUCTION

Under the 1977 Amendments to the Clean Air Act, the U.S. Congress set a national goal calli ngfor “ the prevention of any future, and the remedying of any existing, impairment of visibili ty inmandatory Class I Federal areas which impairment results from manmade air pollution.” TheAmendments required the Environmental Protection Agency (EPA) to issue regulations thatassure “ reasonable progress” toward the national goal. In 40 CFR 51 Subpart P, the EPA issuedthe regulations known as the Regional Haze Rule that are aimed at improving visibili tyconditions and decreasing haze in 156 national parks and wilderness areas (the mandatory Class Iareas where visual range is considered a significant parameter).

The Regional Haze Rule sets a timeline that requires States to aim for restoring naturalconditions by 2064. For the time period from 2014 through 2018 and every ten years after that,the States must demonstrate that they have met reasonable progress goals. To accomplish thistask, monitoring programs have been established in the Class I areas to measure visibili tyimpairment and determine the types of particulate matter which extinguish light in these areas.The Regional Haze Rule (40CFR51.301(bb)) specifies that the deciview haze index should beused to determine progress and that the deciviews are calculated from the formula

deciview haze index = 10 ln (bext/10 Mm-1) [1-1]

where bext represents the total Atmospheric Light Extinction coeff icient calculated from aerosolmeasurements.

The EPA is developing guidance to help the States and regional planning organizations trackprogress under the regional haze program. The guidance will be based on recommendationsfrom the EPA-Federal Land Manager Group on Regional Haze Guidance for Tracking Progress.The workgroup discusses issues associated with the calculation of regional haze conditions, andthe tracking of progress, such as accounting for regional differences, choosing appropriate lightextinction coeff icients, and the approaches for dealing with missing data.

Light extinction from a single species is calculated by multiplying a scattering or absorptioneff iciency for that species by the concentration of that species.1 Some chemical species arehygroscopic, so the scattering efficiency depends on the water content of the species. The lightextinction (bscattering) from a single species is then expressed as

bscattering (in Mm-1) = dry specific scattering eff iciency (in m2/g)× relative humidity weighting factor (dimensionless)× species concentration (in µg/m3)

The formula most commonly used by visibili ty experts working in the national parks andwilderness areas and the one currently being considered by the Tracking Progress Workgroup2

for calculating total Atmospheric Light Extinction values from aerosol measurements1 is li stedbelow:

Atmospheric Light Ext. (Mm-1) = 3 m2/g × f(RH) × [Sulfate] [1-2]

1 - 2

+ 3 m2/g × f(RH) × [Nitrate]+ 4 m2/g × [Organic Carbon]+ 10 m2/g × [Elemental Carbon]+ 1 m2/g × [Soil]+ 0.6 m2/g × [Coarse Mass]+ bRayleigh

The f(RH) multiplier represents a dimensionless weighting factor based on relative humidity(RH) that accounts for the hygroscopicity of certain particulate species, [Sulfate] the measuredconcentration of sulfate species as H2SO4, [Nitrate] the measured concentration of nitrate speciesas HNO3, [Organic Carbon] the total organic carbon concentration, [Elemental Carbon] the lightabsorbing carbon concentrations, [Soil] the soil concentration approximated by measured soilconstituent concentrations, [Coarse Mass] the difference between the particulate matter measuredon 10-micron filters and particulate matter concentrations reconstructed from measurements on2.5-micron filters, and bRayleigh the light extinction from Rayleigh light scattering by gases in theatmosphere. All concentrations are reported in micrograms per cubic meter.

Equation 1-2 shows that the calculation of total Atmospheric Light Extinction requires bothspeciated particulate concentrations and a weighting factor to account for the hygroscopic natureof sulfates and nitrates. Figure 1-1 shows the weighting factor curve used by the TrackingProgress Workgroup, based on laboratory and field work.1 This non-linear curve suggests thatthe light extinction and the deciview haze indices are highly dependent on the RH conditions atany site with significant sulfate and/or nitrate concentrations.

Figure 1-1. Weighting Factor Curve for the Hygroscopicity of Sulfates and Nitrates

The National Park Service Air Resources Division has collected RH data at approximately 50sites during the last twelve years. However, further expansion of the instrumentation used tocollect RH measurements will be limited. Of the 156 Class I areas, only about one quarter willhave RH measurements collected directly in their Class I area. To accommodate limited

02468

101214161820

20 30 40 50 60 70 80 90 100Relative Humidity (percent)

Wei

gh

ting

Fac

tor,

f(R

H)

1 - 3

monitoring resources, the 156 Class I areas were grouped into 108 clusters. Each clustercontains at least one IMPROVE particulate sampler, and the behavior at all of the areas withinthe cluster will be characterized by the cluster monitor(s).

Recognizing that a data gap for RH measurements would persist in future years, the TrackingProgress Workgroup concluded that f(RH) factors needed to be established to describe eachClass I area. Since RH conditions vary from season to season and even from day to day, anacceptable proposed compromise allows the local f(RH) values to be described on a monthlybasis. To avoid changes in the RH readings in future years (which may have been based onexceptional weather conditions or even on new monitor information), the workgroup chose touse climatological averages instead of data collected each year. Recognizing that RH may varyconsiderably geographically, the workgroup chose to find f(RH) values for each individual ClassI area rather than estimating regional averages.

Chapter 2 describes how the data were processed to find monthly average f(RH) factors for eachindividual Class I area and for the 15,000 ¼-degree grid cells of latitude/longitude across theUnited States. Monthly maps are also presented to ill ustrate how f(RH) varies across the UnitedStates and during a year.

Chapter 3 examines the monthly f(RH) factors at the individual Class I areas and how they relatewithin an IMPROVE cluster. In clusters where the Class I areas do not show similar monthlyf(RH) values, it may be diff icult to determine the contributions to light extinction of differentaerosol species. This chapter discusses some ways that the clusters could be realigned.

Chapter 4 uses the monthly f(RH) values and IMPROVE particulate sampler data at ten sites todetermine annual visibilit y impairment, as measured under the Regional Haze Rule. The outlierswithin the data sets are identified, segregated, and new annual visibili ty impairment values aredetermined. This outlier analysis points out the effects that the outlier values have on theregional haze calculations.

2 - 1

2. DATASETS FOR CALCULATINGVISIBILITY IMPAIRMENT

The EPA’s Regional Haze Rule directs that visibili ty conditions in 156 national parks andwilderness areas should improve during the next sixty years. Since visibili ty varies with airquali ty, the contrast between objects, the angle of the sun, and other factors, visibili tyimpairment is measured in the Regional Haze Rule from the calculated light extinction, based on24-hour concentrations of ambient particulate matter species. Sulfate and nitrate particulatespecies scatter more light when the relative humidity is high, so a relative humidity weightingfactor is included in the calculation. However, relative humidity is not routinely measured in the156 national parks and wilderness areas. Therefore, ten years of hourly relative humidity data at375 weather stations across the United States (from both urban and rural sites) were interpolated(at ¼-degree latitude and longitude increments) to estimate monthly average values of the lightextinction weighting factors for sulfate and nitrate anywhere in the country.

2.1 METHODOLOGY

The EPA Tracking Progress Workgroup established the procedures for determining monthlyaverage f(RH) values. The procedures aimed to develop climatological f(RH) factors for Class Iareas as well as other areas of the United States. Since the curve in Figure 1 is nonlinear, theclimatological f(RH) values will be dependent on the distribution of hourly RH measurements.

Hourly relative humidity (RH) measurements for 292 National Weather Service (NWS) stationsacross the 50 States and District of Columbia were collected.2 In addition, at least five years ofhourly RH measurements were available from 25 IMPROVE and IMPROVE protocol monitorsites,3 46 CASTNet sites,4 and 12 additional sites administered by the National Park Service.5

The hourly RH data were converted into RH weighting factors using the nonlinear curveprovided in Figure 1-1. The curve describes RH values from 1 to 98 percent and f(RH) valuesfrom 1 to 26. An hourly f(RH) value was calculated for each valid hourly RH measurement inthe weather station data.

Daily average f(RH) values were calculated from the valid hourly data. Using data from 1988through 1997, only days with at least 16 valid hourly RH values (i.e., between 1 and 98 percent,inclusive) were processed. To represent the fraction of RH readings excluded by cutting offvalues above 98 percent, Figure 2-1 shows the cumulative probabiliti es that hourly NWS stationRH measurements were equal to or less than a particular percentage. Several curves showuneven steps, especially at RH greater than 90 percent. This behavior can be explained becausecertain RH values (in particular, 95, 98, and 99 percent) were only reported sparsely in the NWSdata sets.

In the southwestern states, more than 95 percent of the hourly observations were less than 95%RH and more than 98 percent were below 98% RH. In the southeastern states, fewer than 89percent of the readings were accounted for at 95% RH and fewer than 96 percent of the readingsat 98% RH. This analysis suggests that a 95% RH cutoff would have ignored more than tenpercent of the readings in the southeast if it had been used when calculating f(RH) values. Since

2 - 2

Figure 2-1. Cumulative Probabili ty of Hourly Relative Humidity Values at NWS Stations

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

80 82 84 86 88 90 92 94 96 98 100

Relative Humidity

Cum

ulat

ive

Fra

ctio

n of

Hou

rly O

bser

vatio

ns

NV, UT

CO, NM, WY

AZ, CA

KS, NE, OK, TX

ID, MT, ND, OR, SD, WA

IA, IL, MO, MN, WI

IN, OH, MI, WV

CT, MA, ME, NH, NJ, NY, RI, VT

DC, DE, MD, NC, PA, VA

AL, AR, KY, LA, MS, TN

FL, GA, SC, PR

AK, HI

southeasternstates

southwesternstates

few values of 99% RH were ever reported at the NWS sites (0.03 percent of the observations),the charts suggest that raising the 98% RH cutoff to 99% RH would likely gain littl e information.

Similar to Figure 2-1, Figure 2-2 shows the cumulative probabiliti es that hourly RHmeasurements at individual IMPROVE stations were equal to or less than a particularpercentage. Since the IMPROVE data represents individual sites and the NWS curves eachrepresented dozens of sites, there is more variabilit y in the IMPROVE charts. Three of theIMPROVE sites in the northwest (Three Sisters, Snoqualmie Pass, and Mount Rainier) show thata 95% RH cutoff would have ignored 34 to 47 percent of the information available at these sites,and a 98% RH cutoff still i gnores 23 to 34 percent of the available hourly information (eightpercent of the readings at the northwestern sites were 99% and the remainder 100%). Similarly,three eastern sites (Acadia, Great Smoky Mountains, and Shenandoah) ignore 14 to 21 percent ofthe observations with a 95% RH cutoff and 6 to 14 percent with a 98% RH cutoff. Theseobservations suggest that a considerable number of hourly data points are ignored whencalculating the monthly average f(RH) values in the northwest and, to a lesser degree, in the east.

Since f(RH) values increase orders of magnitude as RH approaches 100% (Figure 1), a single100% RH measurement could dominate the calculated monthly average f(RH). An alternativecalculation method to include these high RH values would be to truncate values above 98% RHat 98% when calculating daily and monthly f(RH) values. In Spring 2000, the workgroupacknowledged that 100% RH is often associated with precipitation events. Since forms of water(and not particulate matter) impair visibili ty during precipitation events, these 100% RH readingswere excluded from the monthly average f(RH) determination, and the 98% RH cutoff was set asthe workgroup’s proposed approach.

2 - 3

Figure 2-2. Cumulative Probabili ty of Hourly Relative Humidity Values at IMPROVE Stations

0.50

0.55

0.60

0.65

0.70

0.75

0.80

0.85

0.90

0.95

1.00

80 82 84 86 88 90 92 94 96 98 100

Relative Humidity

Cum

ulat

ive

Fra

ctio

n of

Hou

rly O

bser

vatio

ns

AcadiaBadlandsBandelierBig BendBridgerCanyonlandsChiricahuaGlacierGreat BasinGrand CanyonGreat SmokiesGuadalupeLone PeakMesa VerdeMt. RainierPet. ForestPinnaclesRocky Mtn.San GorgonioShenandoahSnoq. PassThree SistersYosemiteAverage

northwest sites

eastern sites

The daily averages were combined for all years from 1988 through 1997 to find climatologicalmonthly f(RH) averages. Figure 2-3 shows the cumulative distribution of the ratio of daily-to-monthly f(RH) values. The graph shows that 80 percent of the daily data falls between 0.5 and1.6 times the monthly f(RH), and this is true for both the NWS stations and the IMPROVE sites.

Figure 2-3. Distribution of Daily f(RH) Values about the Monthly Averages

00.10.20.30.40.50.60.70.80.9

1

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4 2.6 2.8 3

daily f(RH)/monthly f(RH)

Cum

ulat

ive

Fra

ctio

n of

Day

s

IMPROVE (57062 days)NWS (988545 days)

2 - 4

Lastly, all monthly average f(RH) values based on fewer than 140 days of data over the 10-yearperiod were removed. This criteria ensured that variations caused by a single climatologicalcondition (e.g., those caused during El Niño years) would not dominate the data set describing asite.

The monthly average f(RH) values at the weather stations were used as the basis for the datadescribing the entire country. Monthly average f(RH) values were interpolated at ¼-degreeincrements using the inverse distance weighting technique (with a distance interpolationexponent of 1):

where the monthly f(RH)g of the grid cell i s calculated from f(RH)w, the monthly f(RH) at theweather station, and xwg, the horizontal distance between the grid cell center and the weatherstation, summed over all of the valid weather stations within a 250-mile radius (350 miles inAlaska). No f(RH) values were corrected for elevation or temperature, but the elevation at whichthe data is interpolated is presented by the HazeCalc tool. The ¼-degree grid resolution (28-kmgrid cells) was chosen so that the map generation files and the associated computer software forall States could be handled easily on a personal computer without significant memoryconsumption.

Figure 2-4 plots the interpolated monthly average f(RH) values against the measured monthlyaverage f(RH) values at IMPROVE sites with at least seven monthly f(RH) values. This chartill ustrates how well the interpolation process approximates the monthly f(RH) at IMPROVEsites. The mean normalized error for the nineteen IMPROVE sites was 6 percent, the meannormalized bias 1 percent, and the mean correlation 0.97. Table 2-1 provides statistics on theindividual sites.

∑∑

wg

wgw

g x1

xRHf = RHf

)()( [3]

2 - 5

Figure 2-4. Agreement Between Monthly Average f(RH) Values and Interpolated Values forthe Same Sites

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

Interpolated monthly average f(RH)

Mea

sure

d m

onth

ly a

vera

ge f(

RH

)

Acadia NP

Badlands NM

Bandelier NM

Big Bend NP

Bridger Wilderness

Canyonlands NP

Chiricahua NM

Denali NP

Everglades NP

Glacier NP

Grand Canyon NP

Guadalupe Mountains NP

Isle Royale NP

Petrified Forest NP

Redwood NP

San Gorgonio Wilderness

Shenandoah NP

Yosemite NP

White-filled symbols show interpolations with more than 1000 feet difference in elevation.

2 - 6

Table 2-1. Agreement Between Measured and Interpolated Monthly Average f(RH) Values atIMPROVE Sites

IMPROVE SiteMean Monthly

ErrorMean Monthly

BiasCorrelationCoefficient

Acadia National Park 0.24 -0.23 0.96Badlands National Monument 0.05 0.02 0.98Bandelier National Monument 0.02 0.01 1.00Big Bend National Park 0.14 0.14 0.99Bridger Wilderness 0.04 -0.03 0.99Canyonlands National Park 0.08 0.08 1.00Chiricahua National Monument 0.06 -0.04 0.99Denali National Park 0.16 0.16 0.98Everglades National Park 0.19 0.19 0.96Glacier National Park 0.29 -0.29 0.93Grand Canyon National Park 0.04 0.00 0.99Guadalupe Mountains National Park 0.02 -0.01 1.00Isle Royale National Park 0.30 0.30 0.82Petrified Forest National Park 0.03 0.01 1.00Redwood National Park 0.22 -0.11 0.99Rocky Mountain National Park 0.03 0.03 0.99San Gorgonio Wilderness 0.24 0.01 0.99Shenandoah National Park 0.60 -0.60 0.95Yosemite National Park 0.20 -0.06 0.98Average 0.16 -0.03 0.97

The IMPROVE site at Isle Royale National Park (located in the northern half of Lake Superiorand shown in Figure 2-5) had the lowest correlation coeff icient in Table 2-1 because thedeviation was high in September and November. The Isle Royale monitor data was not includedin the interpolation scheme for these months because only 126 and 117 daily observations wereavailable (the minimum number for inclusion was 140). The next nearest site with valid datawas Duluth International Airport, 190 miles away, and the Duluth monthly average f(RH) valueswere twenty percent higher than those measured at Isle Royale. This discrepancy betweenvalues suggests that additional RH monitoring at Isle Royale may help create a better descriptionof the visibili ty conditions in September and November.

The Shenandoah IMPROVE site showed the largest errors in Table 2-1, but Figure 2-6 presentsan explanation. The figure shows the Shenandoah IMPROVE site in yellow within the red-hatched grid cell . The other RH monitors in the park are displayed as trees at Dickey Ridge andSawmill Run, and the airport RH monitors are shown 40 to 70 miles east and west of the park.The errors may be caused because the Dickey Ridge and Sawmill Run monitors operate nearbywithin Shenandoah National Park at elevations more than 1500 feet lower than the 3520-feetstation at Big Meadows (8.5 miles from the red-hatched grid cell center). The Dickey Ridge andSawmill Run sites are located 18 and 44 miles from the grid cell center, and their monthlyaverage f(RH) values are 35 percent lower than those at Big Meadows.

2 - 7

Figure 2-5. Relative Humidity Monitors Near Isle Royale National Park

If the monthly average f(RH) values associated with lower elevations are used at Shenandoah,the calculated haze index will reflect the effects of looking down from Big Meadows into andacross the valleys at lower elevations. Valleys in and near Shenandoah National Park constitutea portion of the integral vista defined in the Regional Haze Rule, so the interpolation betweenhigh and low RH monitor sites to describe the Shenandoah IMPROVE monitor haze index maybe considered appropriate.

Figure 2-6. Relative Humidity Monitors Near Shenandoah National Park

��

��

0 15

miles

30

Do ll y Sod s a n dO tter C reek

W i ld ern ess A reas

Sh en ando ah NP

1,948 ft

Sawmill Run1,460 ft

B ig Meadows3,520 ft

D ickey R idge2,000 ft

13 ft

290 ft

��

��

��

50miles

0 100

Isle Royale NP

Eau ClaireCounty Airport

Perkinstown CASTNet

Voyageurs NP

SaultSte Marie

Minneapolis-St Paul Intl

Houghton Lake Roscommon

Traverse CityGreen Bay

InternationalFalls

Duluth IntlAirport

ALPENA PHELPS COLLINS APRK134

2 - 8

2.2 RESULTS AND DISCUSSION

Figures 2-7 through 2-30 show the monthly f(RH) values interpolated from the 375 sites for eachmonth. The maps show individual f(RH) ranges over 0.5 increments. Figures 2-7 through 2-18show all of the weather stations on the maps so that readers can identify where observations froma single monitor change the f(RH) significantly. For example, the concentric circles on Figure 2-10 show that the April f(RH) factor at Mount Rainier (in Washington state) was more than oneunit higher than the f(RH) at surrounding monitors. These concentric circles around rural sites(IMPROVE, CASTNet, and NPS monitor locations) appear infrequently on the monthly maps,and this finding indicates that the RH conditions at the rural sites do not differ significantly fromthose at the NWS stations.

Comparison of the January and August maps (Figures 2-19 and 2-26) ill ustrates that the averagef(RH) values decrease from 2.9 to 2.4 in the West from January to August, and they increasefrom 3.2 to 3.6 in the East. The month of August shows the largest variations in f(RH) sinceNevada, Utah, and Idaho show monthly f(RH) values less than 1.5 and southeastern states havef(RH) values between 4 and 5. In August some Alaskan islands show monthly f(RH) valuesover 6.

2 -

9

Fig

ure

2-7.

Mon

thly

Ave

rage

f(R

H)

Val

ues

for

Janu

ary

(all

wea

ther

sta

tion

s sh

own)

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

� �Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

iteN

PS

Site

IMP

RO

VE

Site

CA

ST

Net

Site

(198

8 -

1997

)

2 -

10

Fig

ure

2-8.

Mon

thly

Ave

rage

f(R

H)

Val

ues

for

Febr

uary

(al

l w

eath

er s

tati

ons

show

n)

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

� �Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

iteN

PS

Site

IMP

RO

VE

Site

CA

ST

Net

Site

2 -

11

Fig

ure

2-9.

Mon

thly

Ave

rage

f(R

H)

Val

ues

for

Mar

ch (a

ll w

eath

er s

tati

ons

show

n)

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

ite

NP

S S

iteIM

PR

OV

E S

ite

CA

ST

Net

Site

2 -

12

Fig

ure

2-10

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r A

pril

(all

wea

ther

sta

tion

s sh

own)

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

� �Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

ite

NP

S S

iteIM

PR

OV

E S

ite

CA

ST

Net

Site

2 -

13

Fig

ure

2-11

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r M

ay (

all

wea

ther

sta

tion

s sh

own)

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

�Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

ite

NP

S S

iteIM

PR

OV

E S

ite

CA

ST

Net

Site

2 -

14

Fig

ure

2-12

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r Ju

ne (a

ll w

eath

er s

tati

ons

show

n)

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

� �Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

ite

NP

S S

iteIM

PR

OV

E S

ite

CA

ST

Net

Site

2 -

15

Fig

ure

2-13

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r Ju

ly (

all

wea

ther

sta

tion

s sh

own)

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

� �Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

ite

NP

S S

iteIM

PR

OV

E S

ite

CA

ST

Net

Site

2 -

16

Fig

ure

2-14

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r A

ugus

t (al

l w

eath

er s

tati

ons

show

n)

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

� �Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

ite

NP

S S

iteIM

PR

OV

E S

ite

CA

ST

Net

Site

2 -

17

Fig

ure

2-15

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r S

epte

mbe

r (a

ll w

eath

er s

tati

ons

show

n)

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

� �Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

ite

NP

S S

iteIM

PR

OV

E S

ite

CA

ST

Net

Site

2 -

18

Fig

ure

2-16

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r O

ctob

er (

all

wea

ther

sta

tion

s sh

own)

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

� �Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

ite

NP

S S

iteIM

PR

OV

E S

ite

CA

ST

Net

Site

2 -

19

Fig

ure

2-17

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r N

ovem

ber

(all

wea

ther

sta

tion

s sh

own)

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

� �Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

ite

NP

S S

iteIM

PR

OV

E S

ite

CA

ST

Net

Site

2 -

20

Fig

ure

2-18

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r D

ecem

ber

(all

wea

ther

sta

tion

s sh

own)

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

��

� �Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

NW

S S

ite

NP

S S

iteIM

PR

OV

E S

ite

CA

ST

Net

Site

2 -

21

Fig

ure

2-19

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r Ja

nuar

y

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

0

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

5

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

0

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

5

2 -

22

Fig

ure

2-20

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r F

ebru

ary

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

0

2 -

23

Fig

ure

2-21

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r M

arch

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

0

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

5

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

0

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

5

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

0

2 -

24

Fig

ure

2-22

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r A

pril

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

0

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

5

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

0

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

5

2 -

25

Fig

ure

2-23

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r M

ay

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

0

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

5

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

0

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

5

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

0

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

5

2 -

26

Fig

ure

2-24

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r Ju

ne

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

0

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

5

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

0

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

5

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

0

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

5

2 -

27

Fig

ure

2-25

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r Ju

ly

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

0

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

5

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

0

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

5

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

0

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

5

2 -

28

Fig

ure

2-26

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r A

ugus

t

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

0

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

52.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

5

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

0

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

5

2 -

29

Fig

ure

2-27

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r S

epte

mbe

r

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

0

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

52.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

5

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

0

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

5

2 -

30

Fig

ure

2-28

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r O

ctob

er

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

52.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

5

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

0

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

51.

0 -

1.5

1.0

- 1.

5

2 -

31

Fig

ure

2-29

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r N

ovem

ber

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

5

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

01.

5 -

2.0

1.5

- 2.

0

2 -

32

Fig

ure

2-30

. M

onth

ly A

vera

ge f(

RH

) V

alue

s fo

r D

ecem

ber

Rel

ativ

e H

umid

ityW

eigh

ting

Fac

tors

> 6

5.5

- 6.

05.

0 -

5.5

4.5

- 5.

04.

0 -

4.5

3.5

- 4.

03.

0 -

3.5

2.5

- 3.

02.

0 -

2.5

1.5

- 2.

01.

0 -

1.5

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

03.

5 -

4.0

3.5

- 4.

0

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

53.

0 -

3.5

3.0

- 3.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.0

- 2.

52.

0 -

2.5

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

02.

5 -

3.0

2.5

- 3.

0

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

0 -

4.5

4.0

- 4.

54.

5 -

5.0

4.5

- 5.

04.

5 -

5.0

4.5

- 5.

04.

5 -

5.0

4.5

- 5.

04.

5 -

5.0

4.5

- 5.

04.

5 -

5.0

2-33

2.3 CONCLUSIONS

To calculate visibili ty conditions under the EPA’s Regional Haze Rule, investigators need bothmeasurements of particulate matter concentrations and information about the relative humidityconditions (to account for the hygroscopicity of sulfate and nitrate particles). Through a series ofdiscussions, and via guidance under development by EPA, the Tracking Progress Workgroup hasdefined a method for using monthly average RH weighting factors. Using data from 375 monitorlocations, the climatological monthly average weighting factors were interpolated to form a15,000-record data set resolved to ¼-degree increments of latitude and longitude. Through theuse of this data set, resources do not need to be directed into future RH monitoring efforts unlessthe regional monthly f(RH) averages are considered inappropriate (e.g., nearby monitors may notadequately describe Isle Royale National Park, so this location would benefit from additionalmonitoring data).

2.4 REFERENCES

1. Malm, W.C. Spatial and Seasonal Patterns and Temporal Variability of Haze and ItsConstituents in the United States: Report III.http://vista.cira.colostate.edu/improve/Publications/improve_reports.htm (accessedJanuary 2001).

2. EPA memorandum, dated August 27, 1999, Summary of July 28-29 Meeting of EPA –Federal Land Manager Group on Regional Haze Guidance for Tracking Progress, byRich Damberg, EPA, Office of Air Quali ty Planning and Standards.

3. NCDC Surface Airways disks produced by EarthInfo, Incorporated, 5541 CentralAvenue, Boulder, Colorado, 80301.

4. Data provided by Jim Sisler of Colorado State University.5. CASTNet Meteorological Data page. http://www.epa.gov/acidrain/castnet/metdata.html

(accessed October 2000).6. Data provided by David Joseph of National Park Service Air Resources Division

(November 2000).

3 - 1

3. CLASS I AREA CLUSTER ANALYSESBASED ON MONTHLY AVERAGE F(RH) VALUES

In December 1998 the IMPROVE Steering Committee approved a list of geographic clusters formonitoring purposes. For all of the mandatory Class I areas within each cluster, a singleIMPROVE monitor should be able to describe the regional haze situation at all Class I areaswithin the cluster. By clustering sites, the IMPROVE Steering Committee was able to directlimited resources to create a monitoring network that can describe conditions in all mandatoryClass I areas. According to “ IMPROVE Particulate Monitoring Network Procedures for SiteSelection [Feb. 24, 1999],” 108 clusters were tentatively chosen for the 156 mandatory Class Iareas addressed in the EPA’s Regional Haze Rule. Thirty-three of these clusters containedmultiple sites, and the remaining sites were too far apart to be grouped with others for the cluster.

As described in SAIC’s January 5, 2001 report, monthly average relative humidity (RH) andf(RH) values were calculated for 154 of the 156 Class I areas. The monthly average f(RH)values are used to calculate the light extinction caused by sulfates and nitrates. The monthlyaverage f(RH) values were based on hourly measurements between 1988 and 1997 (in which atleast five years of data were required for a site to be included in the interpolation). The monthlyaverage f(RH) values were not corrected for elevation. Table 1 shows the monthly averagef(RH) values calculated for each Class I area.

For clusters with multiple sites, each monthly average f(RH) was compared with the others forthe same month. If all monthly f(RH) values for a cluster agreed within ten percent, the clusterwas considered to show good agreement. Twenty-seven of the thirty-three clusters containingmore than one site showed good agreement. Therefore, the sites within these 27 clusters will allshow similar calculated light extinction values and similar percent contributions from sulfatesand nitrates.

3 - 2

Table 3-1. Monthly Average Relative Humidity Weighting Factors, f(RH), for MandatoryClass I Areas Listed by Cluster

Clu

ster

Class I Area Stat

e

Janu

ary

Feb

ruar

y

Mar

ch

Apr

il

May

June

July

Aug

ust

Sept

embe

r

Oct

ober

Nov

embe

r

Dec

embe

r

1 Acadia NP ME 3.26 2.94 2.84 3.37 3.11 2.98 3.41 3.83 4.04 3.82 3.56 3.532 Moosehorn NWR ME 2.97 2.69 2.66 3.01 2.96 3.10 3.41 3.80 3.91 3.54 3.24 3.202 Roosevelt Campobello

International ParkNB 2.99 2.70 2.65 3.03 2.96 3.09 3.40 3.80 3.91 3.54 3.26 3.22

3 Lye Brook Wilderness VT 2.74 2.56 2.61 2.59 2.82 3.03 3.27 3.56 3.66 3.25 2.93 2.834 Great Gulf Wilderness NH 2.78 2.56 2.58 2.77 2.93 3.22 3.49 3.81 3.98 3.42 3.06 2.924 Pres. Range-Dry River

WildernessNH 2.83 2.59 2.60 2.83 3.04 3.38 3.67 4.00 4.26 3.54 3.14 2.96

5 Brigantine Div. OfForsythe NWR

NJ 2.83 2.64 2.73 2.60 3.03 3.16 3.44 3.72 3.64 3.34 2.85 2.83

6 Shenandoah NP VA 3.07 2.83 2.79 2.53 3.05 3.41 3.54 3.93 3.85 3.21 2.95 3.077 James River Face

WildernessVA 2.83 2.64 2.66 2.43 2.98 3.28 3.39 3.67 3.64 3.15 2.81 2.96

8 Dolly Sods Wilderness WV 2.98 2.79 2.81 2.56 3.12 3.39 3.54 3.87 3.85 3.27 2.97 3.108 Otter Creek Wilderness WV 2.97 2.79 2.82 2.57 3.18 3.50 3.69 4.06 3.96 3.32 2.99 3.149 Mammoth Cave NP KY 3.36 3.10 2.94 2.64 3.23 3.52 3.66 3.88 3.90 3.44 3.17 3.4710 Great Smoky Mtns. NP TN 3.31 3.04 2.91 2.70 3.17 3.86 3.82 3.96 4.24 3.77 3.29 3.4410 Joyce Kilmer-Slickrock

WildernessNC 3.34 3.07 2.94 2.73 3.30 3.79 3.96 4.18 4.23 3.78 3.32 3.46

11 Shining RockWilderness

NC 3.28 3.02 2.94 2.71 3.37 3.87 4.09 4.46 4.37 3.76 3.30 3.39

12 Cohutta Wilderness GA 3.34 3.09 2.95 2.77 3.35 3.80 3.99 4.19 4.22 3.79 3.36 3.4613 Linvill e Gorge

WildernessNC 3.26 3.01 2.95 2.68 3.33 3.93 4.07 4.52 4.38 3.69 3.23 3.36

14 Swanquarter Wilderness NC 2.90 2.70 2.64 2.50 2.87 3.20 3.35 3.51 3.35 3.14 2.82 2.8615 Cape Romain NWR SC 3.25 2.95 2.87 2.84 3.16 3.67 3.64 4.06 4.02 3.68 3.35 3.1916 Okefenokee NWR GA 3.48 3.19 3.11 3.03 3.55 3.73 3.73 4.05 4.01 3.75 3.52 3.5816 Wolf Island Wilderness GA 3.40 3.13 3.05 2.99 3.25 3.69 3.71 4.09 4.04 3.74 3.51 3.4817 St Marks Wilderness FL 3.73 3.42 3.42 3.37 3.51 4.00 4.13 4.38 4.17 3.81 3.71 3.8018 Chassahowitzka NWR FL 3.82 3.47 3.39 3.22 3.29 3.87 3.89 4.18 4.12 3.88 3.68 3.8819 Everglades NP FL 2.74 2.57 2.55 2.40 2.36 2.74 2.61 2.89 2.98 2.78 2.60 2.6820 Breton Wilderness LA 3.74 3.54 3.65 3.62 3.83 4.03 4.30 4.33 4.15 3.71 3.67 3.7121 Sipsey Wilderness AL 3.36 3.09 2.88 2.80 3.28 3.66 3.88 3.90 3.92 3.59 3.27 3.4422 Seney Wilderness MI 3.34 2.84 2.92 2.67 2.64 3.08 3.56 4.03 4.06 3.43 3.59 3.5123 Boundary Waters Canoe

AreaMN 2.98 2.59 2.68 2.35 2.31 2.87 3.11 3.36 3.51 2.78 3.20 3.19

24 Voyageurs NP MN 2.79 2.40 2.37 2.27 2.26 3.07 2.66 2.96 3.17 2.60 2.92 2.8025 Isle Royale NP MI 3.05 2.54 2.67 2.37 2.21 2.58 3.00 3.16 3.78 2.71 3.34 3.3026 Mingo Wilderness MO 3.29 3.04 2.77 2.64 3.04 3.18 3.29 3.46 3.48 3.12 3.09 3.2827 Upper Buffalo

WildernessAR 3.30 2.97 2.72 2.83 3.39 3.43 3.39 3.39 3.58 3.30 3.22 3.34

3 - 3


Clu

ster

Class I Area Stat

e

Janu

ary

Feb

ruar

y

Mar

ch

Apr

il

May

June

July

Aug

ust

Sept

embe

r

Oct

ober

Nov

embe

r

Dec

embe

r

28 Hercules-GladesWilderness

MO 3.22 2.92 2.67 2.71 3.25 3.28 3.28 3.33 3.44 3.08 3.11 3.25

29 Caney Creek Wilderness AR 3.42 3.09 2.85 3.01 3.56 3.57 3.44 3.43 3.63 3.49 3.38 3.5130 Wichita Mountains

WildernessOK 2.72 2.56 2.40 2.44 2.98 2.70 2.32 2.53 2.90 2.62 2.66 2.78

31 Big Bend NP TX 2.00 1.86 1.61 1.52 1.63 1.58 1.69 1.96 2.13 1.86 1.84 1.9132 Carlsbad Caverns NP NM 2.05 1.96 1.59 1.54 1.64 1.56 1.83 2.07 2.20 1.83 1.90 2.1432 Guadalupe Mountains

NPTX 1.96 1.95 1.58 1.48 1.55 1.52 1.87 2.15 2.17 1.78 1.91 2.21

33 Bandelier NM NM 2.23 2.10 1.78 1.60 1.59 1.44 1.73 2.08 1.90 1.65 1.96 2.1634 San Pedro Parks

WildernessNM 2.32 2.14 1.79 1.62 1.59 1.43 1.69 2.02 1.91 1.68 2.05 2.24

35 Pecos Wilderness NM 2.25 2.10 1.79 1.66 1.67 1.52 1.77 2.12 2.00 1.71 2.04 2.2135 Wheeler Peak

WildernessNM 2.34 2.17 1.87 1.75 1.78 1.62 1.79 2.19 2.09 1.77 2.18 2.30

36 Salt Creek Wilderness NM 2.12 1.92 1.53 1.53 1.67 1.56 1.76 1.97 2.12 1.75 1.81 2.0637 White Mountain

WildernessNM 2.09 1.93 1.57 1.45 1.50 1.40 1.79 2.01 2.02 1.69 1.81 2.12

38 Bosque del ApacheWilderness

NM 2.11 1.93 1.57 1.38 1.39 1.28 1.75 1.96 1.86 1.60 1.80 2.15

39 Chiricahua NM AZ 2.02 1.95 1.59 1.25 1.26 1.14 1.82 2.09 1.79 1.47 1.63 2.1739 Chiricahua Wilderness AZ 1.99 1.91 1.57 1.23 1.25 1.14 1.81 2.07 1.78 1.46 1.62 2.1540 Galiuro Wilderness AZ 1.95 1.80 1.54 1.22 1.20 1.10 1.54 1.84 1.63 1.46 1.64 2.1040 Saguaro Wilderness AZ 1.80 1.63 1.43 1.13 1.12 1.05 1.41 1.77 1.55 1.41 1.56 2.0541 Petrified Forest NP AZ 2.38 2.20 1.72 1.40 1.33 1.20 1.52 1.82 1.66 1.58 1.94 2.3042 Gila Wilderness NM 2.07 1.93 1.59 1.32 1.35 1.22 2.08 1.96 1.80 1.56 1.76 2.1743 Mount Baldy

WildernessAZ 2.18 2.04 1.69 1.36 1.32 1.18 1.60 1.89 1.71 1.56 1.81 2.21

44 Superstition Wilderness AZ 2.05 1.92 1.63 1.29 1.25 1.12 1.48 1.74 1.58 1.47 1.68 2.0945 Sierra Ancha Wilderness AZ 2.10 1.97 1.67 1.32 1.27 1.14 1.51 1.79 1.62 1.51 1.72 2.1346 Mazatzal Wilderness AZ 2.07 1.94 1.65 1.31 1.26 1.12 1.46 1.73 1.58 1.48 1.68 2.0946 Pine Mountain

WildernessAZ 2.15 2.03 1.73 1.36 1.30 1.14 1.44 1.75 1.60 1.52 1.73 2.12

47 Sycamore CanyonWilderness

AZ 2.35 2.30 2.24 2.02 1.99 1.91 1.97 2.00 2.03 2.02 1.91 2.04

48 Grand Canyon NP AZ 2.37 2.33 1.91 1.49 1.40 1.18 1.42 1.71 1.62 1.59 1.85 2.2549 Bryce Canyon NP UT 2.62 2.38 1.93 1.62 1.50 1.30 1.31 1.51 1.51 1.61 2.00 2.3949 Zion NP UT 2.65 2.42 1.97 1.62 1.50 1.29 1.24 1.41 1.43 1.57 1.98 2.4150 Canyonlands NP UT 2.60 2.32 1.72 1.57 1.47 1.22 1.30 1.45 1.55 1.61 1.98 2.2851 Arches NP UT 2.62 2.34 1.80 1.64 1.55 1.31 1.36 1.53 1.60 1.64 2.04 2.3452 Capitol Reef NP UT 2.70 2.44 1.95 1.71 1.60 1.36 1.37 1.56 1.62 1.68 2.12 2.4653 Great Sand Dunes NM CO 2.42 2.29 2.01 1.89 1.89 1.75 1.88 2.33 2.19 1.86 2.38 2.38

3 - 4


Clu

ster

Class I Area Stat

e

Janu

ary

Feb

ruar

y

Mar

ch

Apr

il

May

June

July

Aug

ust

Sept

embe

r

Oct

ober

Nov

embe

r

Dec

embe

r

54 Mesa Verde NP CO 2.45 2.28 1.87 1.52 1.47 1.33 1.60 1.98 1.89 1.66 2.11 2.3455 Black Canyon of

Gunnison NPCO 2.38 2.22 1.93 1.89 1.87 1.61 1.68 1.94 1.97 1.77 2.13 2.25

55 La Garita Wilderness CO 2.34 2.20 1.91 1.80 1.79 1.60 1.73 2.08 2.01 1.76 2.17 2.2655 Weminuche Wilderness CO 2.38 2.21 1.85 1.68 1.65 1.46 1.63 1.97 1.92 1.71 2.12 2.2856 Eagles Nest Wilderness CO 2.17 2.17 1.99 2.04 2.13 1.89 1.83 2.04 2.03 1.85 2.14 2.1256 Flat Tops Wilderness CO 2.31 2.19 1.99 2.00 2.02 1.76 1.68 1.85 1.94 1.83 2.15 2.2056 Maroon Bells-

Snowmass WildernessCO 2.17 2.14 1.95 2.03 2.05 1.72 1.86 2.16 2.12 1.82 2.09 2.08

56 West Elk Wilderness CO 2.25 2.17 1.93 1.92 1.93 1.65 1.77 2.07 2.04 1.79 2.11 2.1657 Rawah Wilderness CO 2.05 2.12 2.01 2.14 2.26 2.03 1.84 1.97 1.99 1.88 2.09 2.0257 Rocky Mountain NP CO 1.70 1.90 1.90 2.13 2.26 2.04 1.82 1.96 1.87 1.80 1.84 1.7058 Mount Zirkel

WildernessCO 2.18 2.17 2.02 2.09 2.17 1.92 1.74 1.86 1.95 1.87 2.14 2.11

59 Badlands NM SD 2.64 2.66 2.57 2.42 2.80 2.69 2.49 2.42 2.24 2.26 2.72 2.7260 Wind Cave NP SD 2.52 2.50 2.45 2.45 2.70 2.54 2.28 2.25 2.17 2.22 2.60 2.5561 Theodore Roosevelt NP ND 2.86 2.75 2.76 2.33 2.30 2.48 2.42 2.15 2.16 2.32 3.01 2.9962 Lostwood Wilderness ND 2.99 2.89 2.90 2.32 2.27 2.64 2.68 2.36 2.28 2.36 3.24 3.2163 Medicine Lake

WildernessMT 3.02 2.90 2.87 2.26 2.23 2.48 2.50 2.22 2.23 2.35 3.16 3.17

64 UL Bend Wilderness MT 2.71 2.52 2.50 2.28 2.19 2.18 2.01 1.79 1.90 2.20 2.66 2.6865 Bridger Wilderness in

Bridger-Teton ForestWY 2.52 2.35 2.34 2.19 2.10 1.80 1.50 1.49 1.74 2.00 2.44 2.42

65 Fitzpatrick Wilderness WY 2.51 2.33 2.24 2.13 2.09 1.80 1.51 1.46 1.73 1.98 2.39 2.4466 Grand Teton NP WY 2.62 2.39 2.24 2.10 2.06 1.79 1.52 1.47 1.72 2.00 2.43 2.5566 Red Rock Lakes

WildernessMT 2.73 2.46 2.28 2.12 2.10 1.91 1.67 1.58 1.77 2.07 2.56 2.68

66 Yellowstone NP WY 2.54 2.36 2.27 2.16 2.15 1.94 1.69 1.59 1.79 2.08 2.45 2.5167 North Absaroka

WildernessWY 2.43 2.27 2.24 2.17 2.14 1.93 1.69 1.56 1.76 2.04 2.35 2.40

67 Teton Wilderness WY 2.53 2.35 2.24 2.12 2.10 1.85 1.59 1.51 1.74 2.02 2.40 2.4867 Washakie Wilderness WY 2.50 2.34 2.23 2.12 2.11 1.84 1.56 1.49 1.75 2.00 2.38 2.4668 Jarbidge Wilderness NV 2.95 2.60 2.08 2.12 2.21 2.17 1.58 1.40 1.35 1.63 2.44 2.8069 Craters of the Moon

WildernessID 3.13 2.74 2.28 2.02 2.01 1.81 1.43 1.42 1.57 1.97 2.77 3.04

70 Sawtooth Wilderness ID 3.34 2.87 2.32 2.01 2.00 1.84 1.43 1.40 1.50 1.96 2.94 3.3171 Anaconda-Pintler

WildernessMT 3.32 2.88 2.54 2.35 2.36 2.31 1.96 1.88 2.10 2.52 3.15 3.29

71 Selway-BitterrootWilderness

ID 3.50 3.02 2.59 2.34 2.36 2.31 1.93 1.86 2.09 2.55 3.30 3.50

72 Glacier NP MT 4.01 3.47 3.18 3.06 3.24 3.39 2.76 2.60 3.19 3.45 3.82 3.8973 Bob Marshall

WildernessMT 3.57 3.10 2.77 2.59 2.66 2.70 2.34 2.23 2.58 2.92 3.47 3.54

3 - 5


Clu

ster

Class I Area Stat

e

Janu

ary

Feb

ruar

y

Mar

ch

Apr

il

May

June

July

Aug

ust

Sept

embe

r

Oct

ober

Nov

embe

r

Dec

embe

r

73 Mission MountainWilderness

MT 3.60 3.13 2.73 2.52 2.60 2.62 2.27 2.19 2.50 2.87 3.51 3.59

74 Gates of the MountainWilderness

MT 2.89 2.57 2.42 2.30 2.30 2.27 2.03 1.94 2.12 2.41 2.75 2.81

74 Scapegoat Wilderness MT 3.19 2.81 2.57 2.43 2.45 2.44 2.14 2.04 2.28 2.61 3.08 3.1475 Cabinet Mountains

WildernessMT 3.81 3.27 2.85 2.61 2.66 2.68 2.30 2.18 2.56 2.98 3.70 3.86

76 Eagle Cap Wilderness OR 3.77 3.16 2.47 2.10 2.04 1.87 1.61 1.56 1.61 2.25 3.44 3.9776 Strawberry Mountain

WildernessOR 3.89 3.33 2.75 2.93 2.27 2.39 1.98 1.97 1.87 2.63 3.69 4.07

77 Hells CanyonWilderness

ID 3.70 3.12 2.51 2.17 2.12 2.00 1.63 1.58 1.79 2.41 3.45 3.87

78 Mount Rainier NP WA 4.42 3.96 3.64 4.65 3.06 3.69 3.30 3.50 3.40 4.11 4.66 4.6679 Goat Rocks Wilderness WA 4.25 3.75 3.36 4.24 2.83 3.38 3.03 3.19 3.07 3.77 4.42 4.5579 Mount Adams

WildernessWA 4.29 3.80 3.44 4.40 2.92 3.49 3.12 3.27 3.13 3.86 4.49 4.56

80 Alpine LakesWilderness

WA 4.25 3.79 3.47 3.90 2.93 3.22 2.92 3.12 3.25 3.91 4.47 4.51

81 Glacier Peak Wilderness WA 4.16 3.72 3.42 3.75 2.91 3.16 2.88 3.14 3.33 3.90 4.42 4.4381 North Cascades NP WA 4.10 3.69 3.43 3.74 2.93 3.20 2.93 3.23 3.45 3.93 4.39 4.3882 Pasayten Wilderness WA 4.17 3.72 3.41 3.72 2.89 3.16 2.88 3.15 3.32 3.86 4.42 4.4683 Olympic NP WA 4.51 4.08 3.82 4.08 3.17 3.46 3.12 3.48 3.71 4.38 4.83 4.7584 Mount Jefferson

WildernessOR 4.41 3.90 3.56 3.74 3.07 3.11 2.89 2.91 3.03 3.78 4.55 4.54

84 Mount WashingtonWilderness

OR 4.44 3.93 3.58 3.73 3.09 3.11 2.98 2.91 3.02 3.76 4.56 4.56

84 Three Sisters Wilderness OR 4.47 3.95 3.61 3.72 3.11 3.11 3.00 2.91 3.03 3.79 4.60 4.5785 Mount Hood Wilderness OR 4.29 3.81 3.46 3.87 2.95 3.15 2.85 3.00 3.10 3.86 4.53 4.5586 Crater Lake NP OR 4.57 3.92 3.68 3.36 3.22 2.99 2.84 2.87 3.05 3.59 4.57 4.5686 Diamond Peak

WildernessOR 4.52 3.96 3.64 3.66 3.16 3.12 2.90 2.93 3.05 3.67 4.55 4.57

86 Gearhart MountainWilderness

OR 3.96 3.38 3.06 2.75 2.65 2.48 2.28 2.30 2.38 2.84 3.65 3.84

86 Mountain LakesWilderness

OR 4.29 3.62 3.32 2.98 2.86 2.64 2.49 2.50 2.64 3.10 4.12 4.26

87 Lava Beds Wilderness CA 3.98 3.36 3.07 2.70 2.62 2.43 2.31 2.34 2.42 2.72 3.52 3.8187 South Warner

WildernessCA 3.62 3.08 2.72 2.35 2.29 2.12 1.90 1.92 1.97 2.30 3.05 3.44

88 Redwood NP CA 4.42 3.91 4.56 3.91 4.50 4.70 4.86 4.72 4.31 3.66 3.81 3.4089 Kalmiopsis Wilderness OR 4.54 3.90 3.83 3.45 3.46 3.32 3.20 3.20 3.29 3.56 4.39 4.3290 Caribou Wilderness CA 3.69 3.13 2.83 2.45 2.37 2.17 2.07 2.13 2.20 2.38 3.01 3.4190 Lassen Volcanic NP CA 3.81 3.19 2.91 2.53 2.42 2.19 2.09 2.14 2.23 2.43 3.13 3.5390 Thousand Lakes

WildernessCA 3.81 3.19 2.91 2.53 2.42 2.19 2.09 2.14 2.23 2.43 3.13 3.53

3 - 6


Clu

ster

Class I Area Stat

e

Janu

ary

Feb

ruar

y

Mar

ch

Apr

il

May

June

July

Aug

ust

Sept

embe

r

Oct

ober

Nov

embe

r

Dec

embe

r

91 Point Reyes NS CA 3.63 3.25 3.05 2.66 2.53 2.33 2.48 2.57 2.62 2.65 2.94 3.2792 Pinnacles NM CA 3.16 2.84 2.64 2.44 2.27 2.03 2.03 2.11 2.09 2.26 2.48 2.8792 Ventana Wilderness CA 3.21 2.91 2.76 2.44 2.28 2.10 2.16 2.25 2.24 2.39 2.54 2.9093 Marble Mountain

WildernessCA 4.44 3.79 3.74 3.33 3.37 3.24 3.18 3.19 3.24 3.37 4.12 4.15

93 Yolla Bolly Middle EelWilderness

CA 3.95 3.35 3.14 2.76 2.68 2.47 2.44 2.50 2.56 2.70 3.31 3.62

94 San Rafael Wilderness CA 2.83 2.67 2.65 2.36 2.33 2.32 2.45 2.52 2.43 2.50 2.32 2.5095 Desolation Wilderness CA 3.22 2.77 2.39 2.01 1.84 1.63 1.52 1.57 1.65 1.86 2.40 2.9596 Emigrant Wilderness CA 3.20 2.82 2.52 2.11 1.92 1.68 1.54 1.57 1.59 1.85 2.37 2.8596 John Muir Wilderness CA 2.93 2.64 2.42 2.06 1.89 1.72 1.65 1.69 1.71 1.89 2.23 2.6096 Minarets (in Ansel

Adams Wilderness)CA 3.01 2.69 2.44 2.06 1.88 1.69 1.58 1.61 1.62 1.84 2.25 2.68

96 Mokelumne Wilderness CA 3.21 2.78 2.42 2.04 1.86 1.64 1.53 1.58 1.66 1.86 2.39 2.9396 Yosemite NP CA 3.28 3.02 2.78 2.30 2.09 1.75 1.48 1.47 1.52 1.84 2.36 2.8097 Hoover Wilderness CA 3.13 2.76 2.46 2.06 1.87 1.64 1.50 1.53 1.55 1.80 2.32 2.8097 Kaiser Wilderness CA 3.00 2.68 2.45 2.08 1.89 1.72 1.64 1.67 1.69 1.89 2.27 2.6798 Dome Land Wilderness CA 2.47 2.29 2.18 1.93 1.84 1.77 1.79 1.82 1.81 1.89 1.96 2.1698 Kings Canyon NP CA 2.79 2.55 2.42 2.11 1.89 1.76 1.69 1.70 1.75 1.91 2.27 2.5198 Sequoia NP CA 2.53 2.41 2.43 2.23 1.92 1.79 1.66 1.63 1.75 1.89 2.33 2.2999 Cucamonga Wilderness CA 2.51 2.44 2.39 2.16 2.12 2.07 2.14 2.15 2.16 2.19 2.08 2.2099 San Gabriel Wilderness CA 2.53 2.46 2.42 2.19 2.16 2.12 2.20 2.21 2.23 2.26 2.12 2.2399 San Gorgonio

WildernessCA 2.73 2.77 2.56 2.26 2.19 1.86 1.80 1.85 1.88 1.92 1.93 2.15

99 San Jacinto Wilderness CA 2.45 2.42 2.37 2.15 2.12 2.02 2.08 2.11 2.12 2.12 2.00 2.11100 Agua Tibia Wilderness CA 2.39 2.38 2.40 2.22 2.22 2.18 2.28 2.29 2.32 2.29 2.10 2.16101 Joshua Tree NP CA 2.35 2.30 2.24 2.02 1.99 1.91 1.97 2.00 2.03 2.02 1.91 2.04102 Denali NP AK 2.52 2.33 2.09 1.90 1.87 2.15 2.53 2.99 2.82 2.93 3.02 3.10103 Tuxedni Wilderness AK 3.53 3.31 2.85 2.74 2.68 2.85 3.55 4.00 3.91 3.50 3.53 3.66104 Bering Sea Wilderness AK Five years of meteorological data not available105 Simeonof Wilderness AK 4.26 4.08 3.64 3.88 3.91 4.33 5.01 5.18 4.54 3.80 4.02 4.33106 Virgin Islands NP VI Five years of meteorological data not available107 Hawaii Volcanoes NP HI 3.22 2.93 2.97 2.96 2.95 2.92 3.09 3.24 3.18 3.24 3.66 3.18108 Haleakala NP HI 2.74 2.60 2.60 2.54 2.39 2.34 2.48 2.43 2.39 2.53 2.76 2.70

3 - 7

The f(RH) values for Clusters 74, 76, 86, 87, 93, and 98 did not show good agreement (i.e.,monthly average f(RH) values within ten percent of one another) in most of the months. Cluster74 contains Gates of the Mountain and Scapegoat Wilderness Areas, and their f(RH) values oftendid not agree in colder months. Figure 1 shows Cluster 74 and its nearby Class I areas. Thef(RH) values at Scapegoat Wilderness did not agree much better with those at the Bob MarshallWilderness Area, so there is no reason to recommend moving the Scapegoat Wilderness fromCluster 74 into Cluster 73.

Figure 3-1. IMPROVE Cluster 74 and Nearby Class I Areas

kilometers

0 40 80

Selway-Bitterroot Wilderness (71)

Gates of the MountainsWilderness (74)

ScapegoatWilderness (74)

Bob MarshallWilderness (73)

MissionMountain

Wilderness (73)

Cabinet MountainsWilderness (75)

Glacier NP (72)

3 - 8

Cluster 76 contains Eagle Cap and Strawberry Mountain Wilderness Areas, and their f(RH)values often do not agree in warmer months. Figure 2 shows Cluster 76 and the nearby Cluster77 site. Table 1 shows that the f(RH) values at Eagle Cap Wilderness agree better with those atthe Hells Canyon Wilderness Area than at Strawberry Mountain Wilderness. If Eagle Cap andHells Canyon Wilderness Areas represent Cluster 77 while Strawberry Mountain WildernessArea alone represents Cluster 76, then the f(RH) values would match closely in both clusterswithout creating any new clusters or need for additional resources.


50

kilometers

0 100

Eagle CapWilderness (76)

Hells CanyonWilderness (77)

Strawberry Mountain Wilderness (76)

3 - 9

Cluster 86 contains Crater Lake National Park and Diamond Peak, Gearhart Mountain, andMountain Lakes Wilderness Areas, and their f(RH) values often did not agree year round. Thef(RH) values at Gearhart Mountain Wilderness Area were always lower than those at the otherthree sites. Using the particulate matter sampling data collected at Crater Lake from 1994 to1998, the Crater Lake, Diamond Peak, Gearhart Mountain, and Mountain Lakes visibili tyconditions had averages of 3.6, 3.6, 3.3, and 3.4 deciviews on the best days and averages of 13.4,13.5, 12.9, and 13.1 deciviews on the worst days.

The values at Gearhart Mountain Wilderness Area did match well with those at Lava BedsWilderness Area (Cluster 87). Figure 3 shows both Clusters 86 and 87 and their nearby Class Iareas. Moving Gearhart Mountain Wilderness Area from Cluster 86 to Cluster 87 wouldimprove the agreement in Cluster 86 and would establish two sites in Cluster 87 with similarmonthly average f(RH) values. However, the IMPROVE Steering Committee consideredGearhart Mountain Wilderness to be 600 feet too high to be included in that cluster.

Cluster 87 is currently composed of Lava Beds and South Warner Wilderness Areas, but themonthly average f(RH) values at South Warner are always 0.3 to 0.5 lower than those at LavaBeds. Therefore, the sulfate and nitrate contributions to light extinction at South Warner willalways be lower than those at Lava Beds. The f(RH) values at South Warner Wilderness Areado not closely match those at any other nearby Class I area.

Figure 3-3. IMPROVE Clusters 86 and 87 and Nearby Class I Areas

kilometers

0 40 80South Warner

Wilderness (87)Redwood NP (88)

Marble MountainWilderness (93)

Lava Beds NM (87)

KalmiopsisWilderness (89)

Mountain Lakes Wilderness (86)

GearhartMountain

Wilderness (86)

Crater Lake NP (86)

Diamond Peak Wilderness (86)

Three SistersWilderness (84)

Mount WashingtonWilderness (84)

Strawberry Mountain Wilderness

3 - 10

Cluster 93 contains Marble Mountain and Yolla Bolly Middle Eel Wilderness Areas, and theirf(RH) values did not agree year round. Figure 4 shows Cluster 93 and its nearby Class I areas.Table 1 shows that the f(RH) values at Yolla Bolly Middle Eel Wilderness agree better withthose at Caribou Wilderness, Lassen Volcanic National Park, and Thousand Lakes Wilderness(all forming Cluster 90) than at Marble Mountain Wilderness. If Yolla Bolly Middle EelWilderness Area moved to join the other areas in Cluster 90 and Marble Mountain WildernessArea alone represented Cluster 93, then the f(RH) values would match closely in both clusterswithout creating any new clusters or need for additional resources.


0 40 80

kilometers

Yolla BollyMiddle Eel

Wilderness (93)

Lassen Volcanic NP (90)

Caribou Wilderness (90)

Thousand Lakes Wilderness (90)

Redwood NP (88)

Marble MountainWilderness (93)

Lava Beds NM (87)

GearhartMountain

Wilderness (86)

Mountain Lakes Wilderness (86)

KalmiopsisWilderness (89)

South Warner Wilderness

3 - 11

Cluster 98 contains Dome Land Wilderness Area and Kings Canyon and Sequoia National Parks,and the Dome Land f(RH) values did not agree well with the others from November throughApril . Figure 5 shows Cluster 98 as well as the two clusters further north, Clusters 96 and 97.Table 1 shows that the monthly average f(RH) values in Clusters 96 and 97 agree very well . IfClusters 96 and 97 were grouped into a single cluster, then Dome Land Wilderness could fill t hevacant cluster. The clusters would then be organized in the following groupings:

Potential Cluster 96 – Emigrant, Hoover, John Muir, Kaiser, Minarets, and MokelumneWildernesses and Yosemite National Park(November-April average f(RH) of 2.59)

Potential Cluster 97 – Dome Land Wilderness(November-April average f(RH) of 2.17)

Potential Cluster 98 – Kings Canyon and Sequoia National Parks(November-April average f(RH) of 2.41)

Figure 3-5. IMPROVE Clusters 96, 97, and 98

kilometers

0 50 100Dome Land

Wilderness (98)

VentanaWilderness (92)

Pinnacles NM (92)

Sequoia NP (98)

Kings Canyon NP (98)

KaiserWilderness (97)

John MuirWilderness (96)

MinaretsWilderness (96)

HooverWilderness (97)

Yosemite NP (96)

EmigrantWilderness (96)

MokelumneWilderness (96)

3 - 12

The above recommendations for shifting clusters relied solely on the monthly average f(RH)values and did not consider the proximity to existing monitors, elevations, administrativefunctions, and other factors taken into account by the IMPROVE Steering Committee. Therecommendations were aimed at pointing to Class I areas that will show similar behavior for thecalculated light extinction. Since the calculated light extinction relies on the f(RH) values whensulfate and nitrate concentrations represent a substantial portion of the fine particulate matter, therecommendations above point to those Class I areas that will show similar contributions fromsulfate and nitrate to light extinction. Since all of the clusters in Figures 1 through 5 lie in theWest, the influence of sulfate on light extinction may not be of significant concern. However,the winter nitrate levels in these clusters may still represent a significant portion of the calculatedlight extinction and be affected by the chosen f(RH) values.

4 - 1

4. OUTLIERS AND THEIR EFFECTS ON AVERAGEVISIBILITY IMPAIRMENT CONDITIONS

Measured visibili ty data may contain extreme values, or outliers, that significantly affect theaverage value for a data set. Depending on the frequency and magnitude of the outliers, thecalculated average visibili ty may not present an accurate portrayal of the visibili ty conditions at agiven site. Additionally, the chosen visibili ty measures (aerosol li ght extinction or deciviews)can also affect both the determination of outliers and the effects of outliers on averages. It istherefore necessary to determine the criteria for classifying a data point an outlier and excludingit from the average visibili ty calculation with respect to the Regional Haze Rule. The outliervalues should at least have flags associated with the data to alert planners that the data may notbe typical for the site. This chapter presents an analysis of visibili ty data from ten IMPROVEnetwork sites to aid the Tracking Progress Workgroup in these determinations.

The first section of this chapter describes the methodology used to calculate visibili tyimpairment values from the speciated particulate matter concentrations at the IMPROVEmonitors. The second section summarizes the data analyses performed for the IMPROVE sitesfor individual years and describes the material presented in the appendices. The next sectiondiscusses the distribution of the visibili ty impairment data for the five-year period from 1994through 1998. The frequencies of outlier occurrences and the numbers of observed outliers arediscussed. The fourth section discusses the effect that outliers have on the average visibili tyimpairment values for the period from 1994 through 1998.

4.1 Outlier Analysis Methodology

Speciated particulate matter data files were downloaded from the CIRA ftp site for tenIMPROVE monitors. The monthly average f(RH) values were taken from SAIC’s interpolationof monthly average f(RH) values across the country using RH data from NWS, CASTNet,IMPROVE, and other NPS sites (see 1/5/01 report).

The ten IMPROVE network sites studied are listed in Table 4-1 with some of their monthlyf(RH) values. Sites were chosen because of their data completeness records, especially for theyears from 1994 through 1998. Three sites were chosen to represent the East Coast: Acadia,Dolly Sods, and Great Smoky Mountains. The Denali site represents the conditions in Alaska,the Point Reyes site represents the Cali fornia coast, and the five remaining sites are located inother western states. Great Sand Dunes (Colorado) was included in the set because its 1994outlier had been noted to affect averages in a previous report. Although four of the five westernsites are located in arid regions (the highest monthly average f(RH) was only 2.4), the monthlyf(RH) averages at Crater Lake (2.8 to 4.6) in Oregon were higher than those in all of the westernstates in the data set, including Point Reyes National Seashore.

4 - 2

Table 4-1. IMPROVE Sites Investigated for Outlier Effects.

IMPROVE SiteJanuary

f(RH)Aprilf(RH)

Julyf(RH)

Octoberf(RH)

Acadia National Park, Maine 3.26 3.37 3.41 3.82Bandelier National Monument, New Mexico 2.23 1.60 1.73 1.65Big Bend National Park, Texas 2.00 1.52 1.69 1.86Chiricahua National Monument, Arizona 2.02 1.25 1.82 1.47Crater Lake National Park, Oregon 4.57 3.36 2.84 3.59Denali National Park, Alaska 2.52 1.90 2.53 2.93Dolly Sods Wilderness Area, West Virginia 2.98 2.56 3.54 3.27Great Sand Dunes National Monument,

Colorado2.42 1.89 1.88 1.86

Great Smoky Mountains National Park,Tennessee

3.31 2.70 3.82 3.77

Point Reyes National Seashore, Cali fornia 3.63 2.66 2.48 2.65

The aggregate particulate species concentrations were calculated for each day using thefollowing expressions:

[Sulfate] = 4.125 × [S]

[Nitrate] = 1.29 × [NO3]

[Organic Carbon] = [OC1] + [OC2] + [OC3] + [OC4] +[OP]

[Elemental Carbon] = [EC1] + [EC2] + [EC3] – [OP]

[Soil] = 2.2 × [Al] + 2.49 × [Si] + 1.63 × [Ca] + 2.42 × [Fe] + 1.94 × [Ti]

[Reconstructed Fine Mass] = [Sulfate] + [Nitrate] + [Organic Carbon]+ [Elemental Carbon] + [Soil]

[Coarse Mass] = [Total Mass (MT)] - [Reconstructed Fine Mass]

Then the daily aerosol li ght extinction values were calculated as:

Aerosol Light Extinction (Mm-1) = 3 × f(RH) × [Sulfate]+ 3 × f(RH) × [Nitrate]+ 4 × [Organic Carbon]+ 10 × [Elemental Carbon]+ 1 × [Soil]+ 0.6 × [Coarse Mass]

4 - 3

where the concentrations are expressed in µg/m3 and the f(RH) values are represented by themonthly averages. The deciviews were calculated directly from the aerosol l ight extinction(ALE in Mm-1):

Deciview Index (dv) = 10 × ln [(ALE + 10)/10]

where the Rayleigh light scattering coeff icient is assumed to be 10 Mm-1.

The data were then sorted based on years (or groups of years) and ordered based on theirdeciview indices. The 20th percentile group with the highest deciview values were classified asthe worst days, and the 20th percentile group with the lowest deciview values were classified asthe best days.

4.2 Information on the Individual Sites and Years (Content of Appendices)

Appendix A contains twenty graphs showing each site's cumulative distribution of 1994-1998visibili ty data. Two graphs are shown for each site: the first presents the visibili ty impairment inunits of deciviews, and the second shows aerosol li ght extinction. Each graph displays thecumulative data distribution for the best visibili ty days (lower 20th percentile) and worstvisibili ty days (upper 20th percentile) measured over the five-year period. For each data set, thestandard deviation, σ, was calculated. The arrows above the graphs show the data that fallswithin 2σ of the mean. These ranges always included the maximum value for the best days andthe minimum value for the worst days.

As can be seen in all of the graphs, the data sets for the best days and for the worst days wouldnot be described well by normal distribution curves (normal distribution curves would appear ass-shaped curves). This poor fit to a normal distribution curve is expected since the best days andworst days data sets are actually just subsets to larger data sets. Since a normal distributioncurve is not followed, readers are cautioned not to expect the standard deviations to describe thesame confidence levels used for normal distribution curves (68 percent at 1 standard deviationfrom the mean, 95 percent at 2 standard deviations, 99.7 percent at 3 standard deviations, etc.).

Appendix B contains summaries of the cumulative 1994-1998 data for the best days in units ofdeciviews and light extinction, respectively. The tables include the calculated mean, standarddeviation and the total number of data points for each site. The numbers and percentages ofpoints that fell outside the ranges of the mean ± nσ, the outlier cutoff range, are reported. Thenew averages neglecting the outlier points and the associated percentage changes in the averagesare reported. For the grouping of years 1994-1998 the standard deviations of the best daysvalues were always less than those for the worst days. However, 16 percent of the individualyears showed higher standard deviations on the best days than the worst days for deciviews.

The charts in Appendix C show each site's yearly average visibili ty from 1989 through 1998(except for Dolly Sods which started data collection in 1992) and the numbers for multiple yearsfor the best and worst days. The average visibili ty is compared to the average excluding dataoutside the 2σ cutoff range. Separate graphs are shown for each site for units of deciviews and

4 - 4

aerosol li ght extinction. The source data for these graphs are included in the tables of AppendixC.

4.3 Discussion of Data Distribution

Table 4-2 presents a statistical summary of each site's cumulative 1994-1998 visibili ty data. Thetable includes the mean, median, minimum, maximum, and standard deviation in deciviews andaerosol li ght extinction for both the best and worst days. The standard deviation for the bestvisibili ty days ranged from 0.63 to 2.6 deciviews (Denali to Dolly Sods) and from 0.85 to 8.95Mm-1 for aerosol li ght extinction (Denali to Dolly Sods). For the worst visibili ty days, thestandard deviation ranged from 1.46 to 3.77 deciviews (Bandelier to Point Reyes) and from 5.68to 70.3 Mm-1 for aerosol li ght extinction (Bandelier to Dolly Sods).

Table 4-2. Statistical Summary for the 1994-1998 Visibility Impairment Data.

Best Days - Deciviews Worst Days - DeciviewsLocation Mean Median Min Max σσ Mean Median Min Max σσAcadia 9.16 9.51 3.01 11.2 1.60 23.7 23.2 19.5 34.2 3.27Bandelier 6.01 6.37 3.18 7.13 0.97 12.7 12.2 11.1 16.9 1.46Big Bend 7.70 7.93 3.74 9.75 1.54 17.9 17.4 15.6 25.6 2.00Chiricahua 6.27 6.50 2.43 7.65 1.07 13.6 13.2 11.9 19.9 1.67Crater Lake 3.57 3.80 1.45 4.82 0.88 13.4 13.1 10.9 20.7 2.19Denali 3.04 3.07 1.38 3.89 0.63 9.71 9.21 7.99 21.2 2.03Dolly Sods 13.2 14.1 5.99 16.2 2.60 29.8 29.2 25.3 38.1 3.12Great SandDunes

4.81 4.90 2.35 5.98 0.84 12.3 11.8 10.4 31.8 2.44

Great SmokyMountains

14.1 14.8 5.62 16.4 2.18 30.6 30.7 27.4 36.3 2.21

Point Reyes 8.34 8.74 4.13 10.1 1.44 20.6 19.1 17.2 33.1 3.77

Best Days -Aerosol Light Extinction (Mm-1)

Worst Days -Aerosol Light Extinction (Mm-1)

Location Mean Median Min Max σσ Mean Median Min Max σσAcadia 15.3 15.9 3.52 20.7 3.73 104 91.5 60 295 44.7Bandelier 8.31 8.91 3.74 10.4 1.69 25.9 23.7 20.3 44.4 5.68Big Bend 11.8 12.1 4.54 16.5 3.21 51.1 46.8 37.5 119 14.3Chiricahua 8.82 9.15 2.75 11.5 1.07 29.6 27.3 23.0 63.4 7.88Crater Lake 4.34 4.63 1.56 6.20 1.24 29.3 27.0 19.6 68.9 10.1Denali 3.57 3.60 1.48 4.76 0.85 17.1 15.1 12.2 73.2 7.87Dolly Sods 28.5 30.9 8.19 40.5 8.95 196 175 116 441 70.3Great SandDunes

6.23 6.32 2.64 8.19 1.32 25.8 22.5 18.2 230 21.3


31.9 33.9 7.54 41.6 7.73 210 204 145 368 50.8

Point Reyes 13.3 14.0 5.11 17.4 3.18 75.4 57.8 45.8 263 43.8

4 - 5

When comparing the means and medians in Table 4-2, the mean normalized difference betweenthe two for the best days was 4.3 percent in deciviews and 4.6 percent in aerosol l ight extinction.For the worst visibili ty days, the mean normalized differences between the two were 3.3 percentfor deciviews and 11 percent for aerosol li ght extinction.

Table 4-3 presents the number of points outside the outlier cutoff ranges of 2σ, 3σ, 4σ, and 5σ,for the best and worst days for 1994-1998. For the best visibili ty days, there were more pointsoutside the ranges when using deciviews, but outliers were only present in the range of 3σ orsmaller. For all cutoff ranges on the worst days, there were never fewer points outside the cutoffrange when visibili ty was expressed in aerosol li ght extinction.

Table 4-3. Occurrence of Outliers at All Ten Sites for Various Outlier Cutoff Ranges.

Number of Points* Outside 2σσ Outside 3σσ Outside 4σσ Outside 5σσBest Days (Deciviews) 37 6 0 0Best Days (Light Extinction) 32 4 0 0Worst Days (Deciviews) 37 14 2 2Worst Days (Light Extinction) 42 21 5 2

* 916 Points in Each Data Set

Characteristics of the twenty-one data points li sted in Table 3 as lying outside 3 standarddeviations on the worst days (designated as extreme outliers) are presented in Table 4-4. The lastsix columns of Table 4-4 compare the daily species concentrations for the extreme outliers withthe worst-day mean concentrations. No single composite species can be cited as the cause forthe extreme outliers, and all six composite species contribute to the extreme outliers on at leastfive days. Sulfate was only a major contributor to the extreme outliers in the months from Julyto September, and sulfates and nitrates never both appeared as major contributors on the sameday.

4 - 6

Table 4-4. Extreme Outliers for the Worst Days Data Sets from 1994-1998.

ALE (Mm-1) Deciviews Ratio of daily reading to worst day average

Location Date Mean Outlier Mean Outlier Sulf

ate

Nit

rate

Org

.C

arbo

n

Ele

m.

Car

bon

Fin

eSo

il

Coa

rse

Mas

s

Acadia 9/17/94 * 104 295 23.7 34.2 2.8 -- -- 1.9 2.5 2.18/7/96 104 261 23.7 33.0 2.8 -- -- -- -- --7/15/98 104 245 23.7 32.4 2.7 -- -- 2.2 2.1 --

Bandelier 9/12/98 25.9 44.4 12.7 16.9 2.6 -- -- -- -- --Big Bend 5/20/98 * 51.1 119 17.9 25.6 -- -- 4.6 3.3 -- 2.5

9/2/98 51.1 96 17.9 23.6 2.4 -- -- -- -- --Chiricahua 7/16/94 29.6 57.5 13.6 19.09 -- -- 4.9 3.8 -- --

8/23/95 29.6 55.6 13.6 18.81 2.5 -- -- -- -- --5/20/98 29.6 63.4 13.6 19.93 -- 3.3 7.2 3.6 -- --8/22/98 29.6 61.1 13.6 19.62 2.7 -- -- -- -- --

Crater Lake 8/26/96 29.3 65.9 13.4 20.3 -- 2.0 3.1 3.3 -- 2.48/31/96 29.3 68.9 13.4 20.7 -- -- 4.9 2.1 -- 2.54/29/98 29.3 64.5 13.4 20.1 -- -- -- -- 14.3 4.5

Denali 7/2/97 17.1 47.5 9.7 17.5 -- -- 7.3 2.5 2.2 2.17/9/97 ‡ 17.1 73.2 9.7 21.2 -- -- 12.0 4.7 -- 2.6

Dolly Sods 8/16/95 196 441 29.8 38.1 2.2 -- -- -- 2.1 --Great SandDunes

4/23/94 ‡ 25.8 230 12.3 31.8 -- -- -- -- 11.2 27.3


7/26/97 210 368 30.6 36.3 1.9 -- -- -- -- --

Point Reyes 1/19/94 * 75.4 263 20.6 33.1 -- 5.4 2.4 3.1 -- --1/22/94 75.4 240 20.6 32.2 -- 4.9 -- 2.4 -- --2/5/94 75.4 214 20.6 31.1 -- 4.5 2.5 3.4 -- --

The last six columns show the ratio of the component species measured on that day to the average measurement ofthe component species on the worst days from 1994-1998. For ill ustrative purposes, ratios below 1.9 are not shown.* ALE more than 4 standard deviations from average for worst days.‡ ALE more than 5 standard deviations from average for worst days. No unusual meteorological events wererecorded in the Great Sand Dunes log books for April 23, 1994.3

Figure 4-1 presents the 1994-1998 percentage of outliers at each site for the best days. Thepercentage of outliers is shown for both deciviews and aerosol li ght extinction for 2σ and 3σoutlier cutoff ranges. For the best days, the outlier percentages for the 2σ cutoff range variedfrom approximately 2 to 5 percent for deciviews and 1 to 5 percent for aerosol li ght extinction.The outlier percentages for aerosol li ght extinction were never more than those for deciviews forthe best days at each site.

An identical analysis is shown in Figure 4-2 for the worst visibili ty days. The worst days' outlierpercentages for the 2σ cutoff ranged from approximately 1 to 6 percent for deciviews and from 1to 7 percent for aerosol li ght extinction. The outlier percentages for aerosol li ght extinction werenever less than those for deciviews for the worst days at each site. The worst days at Great Sand

4 - 7

Dunes had only one percent of the points outside the ranges because the standard deviation (21.5Mm-1) was so large compared to the average (26.0 Mm-1).

Figure 4-1. Occurrence of Outliers at IMPROVE Sites: 1994-1998, Best Days

Figure 4-2. Occurrence of Outliers at IMPROVE Sites: 1994-1998, Worst Days

0

1

2

3

4

5

6

7

8

9

10

Acadia Bandelier Big Bend Chiricahua CraterLake

Denali Dolly Sods Great SandDunes

GreatSmoky

Mountains

PointReyes

NationalSeashore

Per

cent

enta

ge o

f Dat

a O

utsi

de S

peci

fied

Ran

ge

mean ± 2 s.d (deciviews) mean ± 3 s.d. (deciviews) mean ± 2 s.d. (light ext.) mean ± 3 s.d. (light ext.)

0

1

2

3

4

5

6

7

8

9

10



GreatSmoky

Mountains

PointReyes

NationalSeashore

Per

cent

enta

ge o

f Dat

a O

utsi

de S

peci

fied

Ran

ge

mean ± 2 s.d (deciviews) mean ± 3 s.d. (deciviews) mean ± 2 s.d. (light ext.) mean ± 3 s.d. (light ext.)

4 - 8

Table 4-5 compares the frequency of outlier occurrences (based on reported units) for all sites.On the best visibili ty days, sites are more likely to have a higher number of outliers when usingdeciviews as the index, and on the worst visibili ty days, sites are more likely to have a highernumber of outliers when using light extinction units.

Table 4-5. Effect of Visibility Units on the Number of Outliers.

Number of sites whereDECIVIEWS had more

outliers

Number of sites wherenumber of outliers

matched for both units

Number of sites whereLIGHT EXTINCTION

had more outliersBest Days Worst Days Best Days Worst Days Best Days Worst Days

Mean ± 2σ 4 0 6 7 0 3Mean ± 3σ 2 0 8 4 0 6Mean ± 4σ 0 0 10 7 0 3Mean ± 5σ 0 0 10 10 0 0

4.4 Effect of Outliers on Averages

Table 4-6 presents the effects of outlier data on the 1994-1998 mean visibilit y impairment for thebest and worst visibili ty days using 2σ and 3σ cutoff ranges. In Figures 4-3 and 4-4 the effect ofoutliers is expressed as the percent difference between the average visibili ty index calculatedusing the entire data set and the index calculated when ignoring the outlier data. Results forindividual years for the 2σ cutoff range at each site are found in Appendix C.

On the best days the percentage increase in average visibili ty indices for the 2σ outlier cutoffranged from 1.1 percent (Denali ) to 2.3 percent (Great Smoky Mountains) for deciviews, and 0.7percent (Denali ) to 3.1 percent (Great Smoky Mountains) for aerosol li ght extinction. Thepercentage increases for the deciviews and aerosol li ght extinction never differed by more thanone percent. For the majority of the sites, no change in the average visibili ty condition wasobserved on the best days when excluding points more than 3σ away from the mean (Figure 4-4)because all of the points for these sites fell within the 3σ cutoff range.Figures 4-5 and 4-6 are analogous graphs for the worst days for the 2σ and 3σ cutoff ranges.The percentage change in average visibili ty for the 2σ outlier cutoff f or the worst days was moresensitive to the index choice than for the best days. Percent changes ranged from 0.4 percent(Great Smoky Mountains) to 3.4 percent (Point Reyes) for deciviews, and 2.1 percent (GreatSmoky Mountains) to 12 percent (Point Reyes) for aerosol li ght extinction. The percentagechange in visibili ty was significantly greater (at least twice as large) for light extinction than fordeciviews at all sites. When examining the 3σ cutoff range (Figure 4-6), the percentage changeranged from 0.8 to 8.5 percent for aerosol l ight extinction at the sites.

In general, for the worst visibili ty days, the effect of using aerosol l ight extinction rather thandeciviews has a more pronounced effect, and a single outlier can significantly affect the average.For example, at Great Sand Dunes National Monument, a single data point was so much largerthan all others that the worst days 2σ cutoff range spanned from -15 to 68 Mm-1. Excluding this

4 - 9

outlier in the analysis resulted in an 1.6 percent decrease in deciviews, but an 8 percent decreasein the average aerosol li ght extinction.

Table 4-6. Effect of Outliers of Average Visibility Impairment at IMPROVE Sites, 1994-1998.*

Best Days - Deciviews Worst Days - Deciviews

Location

Meanusing

allpoints

Meanneglecting

pointsoutside 2σσ

Meanneglecting

pointsoutside 3σσ

Meanusing

allpoints

Meanneglecting

pointsoutside 2σσ

Meanneglecting

pointsoutside 3σσ

Acadia 9.16 9.32 (3) 9.28 (2) 23.7 23.2 (5) 23.6 (1)Bandelier 6.01 6.12 (4) 6.01 (0) 12.7 12.4 (6) 12.7 (0)Big Bend 7.70 7.87 (4) 7.70 (0) 17.9 17.6 (4) 17.8 (1)Chiricahua 6.27 6.40 (4) 6.31 (1) 13.6 13.4 (4) 13.4 (4)Crater Lake 3.57 3.64 (3) 3.57 (0) 13.4 13.0 (5) 13.2 (3)Denali 3.04 3.07 (2) 3.04 (0) 9.71 9.49 (2) 9.49 (2)Dolly Sods 13.2 13.5 (4) 13.2 (0) 29.8 29.5 (3) 29.8 (0)Great SandDunes

4.81 4.92 (5) 4.81 (0) 12.3 12.1 (1) 12.1 (1)


14.1 14.4 (4) 14.4 (3) 30.6 30.5 (2) 30.6 (0)

Point Reyes 8.34 8.52 (4) 8.34 (0) 20.6 19.9 (5) 20.3 (2)

Best Days -Aerosol Light Extinction (Mm-1)

Worst Days -Aerosol Light Extinction (Mm-1)

Location

Meanusing

allpoints

Meanneglecting

pointsoutside 2σσ

Meanneglecting

pointsoutside 3σσ

Meanusing

allpoints

Meanneglecting

pointsoutside 2σσ

Meanneglecting

pointsoutside 3σσ

Acadia 15.3 15.6 (3) 15.4 (1) 104 95.9 (5) 98.3 (3)Bandelier 8.31 8.50 (4) 8.31 (0) 25.9 24.7 (7) 25.7 (1)Big Bend 11.8 12.2 (4) 11.8 (0) 51.1 48.9 (4) 49.9 (2)Chiricahua 8.82 9.03 (4) 8.89 (1) 29.6 28.3 (4) 28.3 (4)Crater Lake 4.34 4.40 (2) 4.34 (0) 29.3 27.3 (5) 27.9 (3)Denali 3.57 3.60 (1) 3.57 (0) 17.1 16.1 (2) 16.1 (2)Dolly Sods 28.5 29.2 (3) 28.5 (0) 196 184 (6) 194 (1)Great SandDunes

6.23 6.39 (5) 6.23 (0) 25.8 23.7 (1) 23.7 (1)


31.9 32.9 (4) 32.4 (2) 210 205 (3) 208 (1)

Point Reyes 13.3 13.4 (2) 13.3 (0) 75.4 66.1 (5) 69.0 (3)*The number of outliers are reported in parentheses.

4 - 10

Figure 4-3. Effect of Values Outside 2σσ on Average Visibility Impairment at IMPROVESites: 1994-1998, Best Days

0

1

2

3

4



GreatSmoky

Mountains

PointReyes

NationalSeashore

Per

cent

Incr

ease

Exc

ludi

ng O

utlie

rs

Deciviews Light Extinction

0

1

2

3

4



GreatSmoky

Mountains

PointReyes

NationalSeashore

Per

cent

Incr

ease

Exc

ludi

ng O

utlie

rs

Deciviews Light Extinction

Figure 4-4. Effect of Values Outside 3σσ on Average Visibility Impairmentat IMPROVE Sites: 1994-1998

4 - 11

Figure 4-5. Effect of Values Outside 2σσ on Average Visibility Impairment at IMPROVESites: 1994-1998, Worst Days

Figure 4-6. Effect of Values Outside 3σσ on Average Visibility Impairment at IMPROVESites: 1994-1998, Worst Days

0

1

2

3

4

5

6

7

8

9

10

11

12

13


Denali Dolly Sods GreatSandDunes

GreatSmoky

Mountains

PointReyes

NationalSeashore

Per

cent

Dec

reas

e E

xclu

ding

Out

liers

Deciviews

Light Extinction

0

1

2

3

4

5

6

7

8

9

10

11

12

13


Denali Dolly Sods GreatSandDunes

GreatSmoky

Mountains

PointReyes

NationalSeashore

Per

cent

Dec

reas

e E

xclu

ding

Out

liers

Deciviews

Light Extinction

4 - 12

4.5 Conclusions

Many statistics on the individual years are presented in Appendix C, but tracking progress underthe Regional Haze Rule involves the investigation of f ive continuous years of data. This chaptersummarizes numerous statistics on the average calculated visibili ty conditions at ten IMPROVEsites for the period from 1994 through 1998. The standard deviations are presented, and outliersare determined for various cutoff ranges. The effects of the outliers on the average visibili tyconditions are also examined. When examining the 1994-1998 groups of data at the tenIMPROVE sites, the following observations were made:

1. The means and medians agreed well on the best days (normalized error between them of 4.3percent for deciviews and 4.6 percent for light extinction), and the worst days for deciviews(3.3 percent), but not on the worst for light extinction (10.5 percent).

2. The standard deviations for the best days ranged from 0.63 to 2.6 deciviews and from 0.85 to8.95 Mm-1 for light extinction. The standard deviations for the worst days ranged from 1.46to 3.77 deciviews and from 5.68 to 70.3 Mm-1 for light extinction.

3. The number of points lying outside the outlier cutoff ranges was higher when using adeciview scale on the best days and when using a light extinction scale on the worst days.

4. On the best days, no points in a data set of 916 points (all ten sites for five years) werelocated more than 4 standard deviations from the average values for that site.

5. On the worst days, two points in a data set of 916 points (all ten sites for five years) werelocated more than 5 standard deviations from the average values for that site. Depending onthe sample, each of the six composite species helped to create the extreme outliers beyond 3standard deviations from the averages on the worst days.

6. On the best days 1 to 5 percent of the points were outside the 2σ cutoff range at the ten sites.7. On the worst days 1 to 7 percent of the points were outside the 2σ cutoff range at the ten

sites.8. On the best days, excluding points outside the 2σ cutoff range increases the visibili ty

impairment averages 0.7 to 3.1 percent.9. On the worst days, excluding points outside the 2σ cutoff range decreases the visibili ty

impairment averages 0.4 to 12 percent.

APPENDIX A.

1994-1998 Cumulative Data Distribution

Of Calculated Visibili ty at Ten IMPROVE Sites

A - 2

Figure A-1. Data Distribution from Acadia IMPROVE Monitor (Deciviews), 1994-1998.

Figure A-2. Data Distribution from Acadia IMPROVE Monitor (Light Extinction), 1994-1998.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 50 100 150 200 250 300 350

Aerosol Light Extinction (Mm-1)

Fra

ctio

n of

Poi

nts

� � Aer

osol

Lig

ht E

xtin

ctio

n V

alue

Best Days Worst Days

Arrows indicate data within ± 2σσ of the mean

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 5 10 15 20 25 30 35 40

Deciviews

Fra

ctio

n of

Poi

nts

� � Dec

ivie

w V

alue


Arrows indicate data within ± 2σ σ of the mean

A - 3

Figure A-3. Data Distribution from Bandelier IMPROVE Monitor (Deciviews), 1994-1998.

Figure A-4. Data Distribution from Bandelier IMPROVE Monitor (Light Extinction),1994-1998.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 2 4 6 8 10 12 14 16 18

Deciviews

Fra

ctio

n of

Poi

nts

� � Dec

ivie

w V

alue



0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 5 10 15 20 25 30 35 40 45 50


Fra

ctio

n of

Poi

nts

� � Aer

osol

Lig

ht E

xtin

ctio

n V

alue



A - 4

Figure A-5. Data Distribution from Big Bend IMPROVE Monitor (Deciviews), 1994-1998.

Figure A-6. Data Distribution from Big Bend IMPROVE Monitor (Light Extinction),1994-1998.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 5 10 15 20 25 30

Deciviews

Fra

ctio

n of

Poi

nts

� � Dec

ivie

w V

alue



0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 20 40 60 80 100 120 140


Fra

ctio

n of

Poi

nts

� � Aer

osol

Lig

ht E

xtin

ctio

n V

alue



A - 5

Figure A-7. Data Distribution from Chiricahua IMPROVE Monitor (Deciviews), 1994-1998.

Figure A-8. Data Distribution from Chiricahua IMPROVE Monitor (Light Extinction),1994-1998.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 5 10 15 20 25

Deciviews

Fra

ctio

n of

Poi

nts

Dec

ivie

w V

alue



0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 10 20 30 40 50 60 70 80


Fra

ctio

n of

Poi

nts

Aer

osol

Lig

ht E

xtin

ctio

n V

alue



A - 6

Figure A-9. Data Distribution from Crater Lake IMPROVE Monitor (Deciviews), 1994-1998.

Figure A-10. Data Distribution from Crater Lake IMPROVE Monitor (Light Extinction), 1994-1998.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 5 10 15 20 25

Deciviews

Fra

ctio

n of

Poi

nts

! ! Dec

ivie

w V

alue



0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 5 10 15 20 25

Deciviews

Fra

ctio

n of

Poi

nts

! ! Dec

ivie

w V

alue



A - 7

Figure A-11. Data Distribution from Denali IMPROVE Monitor (Deciviews), 1994-1998.

Figure A-12. Data Distribution from Denali IMPROVE Monitor (Light Extinction), 1994-1998.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 10 20 30 40 50 60 70 80


Fra

ctio

n of

Poi

nts

" " Aer

osol

Lig

ht E

xtin

ctio

n V

alue



0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 5 10 15 20 25 30 35 40 45

Deciviews

Fra

ctio

n of

Poi

nts

" " Dec

ivie

w V

alue


Arrows indicate data within ± 2σ σ of the mean

A - 8

Figure A-13. Data Distribution from Dolly Sods IMPROVE Monitor (Deciviews), 1994-1998.

Figure A-14. Data Distribution from Dolly Sods IMPROVE Monitor (Light Extinction),1994-1998.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 50 100 150 200 250 300 350 400 450 500


Fra

ctio

n of

Poi

nts

# # Aer

osol

Lig

ht E

xtin

ctio

n V

alue



0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 5 10 15 20 25 30 35

Deciviews

Fra

ctio

n of

Poi

nts

# # Dec

ivie

w V

alue



A - 9

Figure A-16. Data Distribution from Great Sand Dunes IMPROVE Monitor (LightExtinction), 1994-1998

Figure A-17. Data Distribution from Great Smoky Mountains IMPROVE Monitor(Deciviews), 1994-1998.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-50 0 50 100 150 200 250


Fra

ctio

n of

Poi

nts

$ $ Aer

osol

Lig

ht E

xtin

ctio

n V

alue



0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 5 10 15 20 25 30 35 40

Deciviews

Fra

ctio

n of

Poi

nts

$ $ Dec

ivie

w V

alue



A - 10

Figure A-18. Data Distribution from Great Smoky Mountains IMPROVE Monitor (LightExtinction), 1994-1998.

Figure A-19. Data Distribution from Point Reyes IMPROVE Monitor (Deciviews), 1994-1998.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 50 100 150 200 250 300 350 400


Fra

ctio

n of

Poi

nts

% % Aer

osol

Lig

ht E

xtin

ctio

n V

alue



0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

0 5 10 15 20 25 30 35

Deciviews

Fra

ctio

n of

Poi

nts

% % Dec

ivie

w V

alue



A - 11

Figure A-20. Data Distribution from Point Reyes IMPROVE Monitor (Light Extinction),1994-1998.

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

-50 0 50 100 150 200 250 300


Fra

ctio

n of

Poi

nts

& & Aer

osol

Lig

ht E

xtin

ctio

n



APPENDIX B.

Calculated Visibili ty Statistics at Ten IMPROVE Sites

And the Effects of Outliers on Averages – 1994-1998

B - 2

Table B-1. 1994-1998 Summary Data for the Best Days (Deciviews)Acadia Bandelier Big

BendChiricahua Crater

LakeDenali Dolly

SodsGreatSandDunes

GreatSmokyMtns

PointReyes

# points 97 96 91 93 86 90 91 100 92 80

Mean 9.16 6.01 7.70 6.27 3.57 3.04 13.18 4.81 14.12 8.34

σ 1.60 0.97 1.54 1.07 0.88 0.63 2.60 0.84 2.18 1.44

# pts outsideof 2 σ

3 4 4 4 3 2 4 5 4 4

Avg negloutside pts

9.32 6.12 7.87 6.40 3.64 3.07 13.48 4.92 14.44 8.52

% of pointsoutside 2 σ

3 4 4 4 3 2 4 5 4 5

% increase inavg negl. otlrs

1.7 1.8 2.2 2.0 2.0 1.1 2.3 2.3 2.3 2.1


2 0 0 1 0 0 0 0 3 0

Avg negloutside pts

9.28 6.01 7.70 6.31 3.57 3.04 13.18 4.81 14.38 8.34


2 0 0 1 0 0 0 0 3 0


1.3 0.0 0.0 0.7 0.0 0.0 0.0 0.0 1.9 0.0

% pts outsideof 4 σ

0 0 0 0 0 0 0 0 0 0

Avg negloutside pts

9.16 6.01 7.70 6.27 3.57 3.04 13.18 4.81 14.12 8.34


0 0 0 0 0 0 0 0 0 0


0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0


0 0 0 0 0 0 0 0 0 0

Avg negloutside pts

9.16 6.01 7.70 6.27 3.57 3.04 13.18 4.81 14.12 8.34


0 0 0 0 0 0 0 0 0 0


0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

B - 3

Table B-2. 1994-1998 Summary Data for the Best Days (Light Extinction)Acadia Bandelier Big


LakeDenali Dolly

SodsGreatSandDunes

GreatSmokyMtns

PointReyes

# points 97 96 91 93 86 90 91 100 92 80

Mean 15.30 8.31 11.84 8.82 4.34 3.57 28.53 6.23 31.89 13.26

σ 3.73 1.69 3.21 1.92 1.24 0.85 8.95 1.32 7.73 3.18


3 4 4 4 2 1 3 5 4 2

Avg negloutside pts

15.62 8.50 12.16 9.03 4.40 3.60 29.19 6.39 32.87 13.44


3 4 4 4 2 1 3 5 4 3


2.1 2.2 2.7 2.4 1.5 0.7 2.3 2.6 3.1 1.4


1 0 0 1 0 0 0 0 2 0

Avg negloutside pts

15.42 8.31 11.84 8.89 4.34 3.57 28.53 6.23 32.42 13.26


1 0 0 1 0 0 0 0 2 0


0.8 0.0 0.0 0.7 0.0 0.0 0.0 0.0 1.7 0.0


0 0 0 0 0 0 0 0 0 0

Avg negloutside pts

15.30 8.31 11.84 8.82 4.34 3.57 28.53 6.23 31.89 13.26


0 0 0 0 0 0 0 0 0 0


0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0


0 0 0 0 0 0 0 0 0 0

Avg negloutside pts

15.30 8.31 11.84 8.82 4.34 3.57 28.53 6.23 31.89 13.26


0 0 0 0 0 0 0 0 0 0


0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

B - 4

Table B-3. 1994-1998 Summary Data for the Worst Days (Deciviews)Acadia Bandelier Big


LakeDenali Dolly

SodsGreatSandDunes

GreatSmokyMtns

PointReyes

# points 97 96 91 93 86 90 91 100 92 80

Mean 23.71 12.66 17.89 13.62 13.42 9.71 29.77 12.25 30.63 20.59

σ 3.27 1.46 2.00 1.67 2.19 2.03 3.12 2.44 2.21 3.77


5 6 4 4 5 2 3 1 2 5

Avg negloutside pts

23.24 12.42 17.61 13.36 13.04 9.49 29.52 12.05 30.51 19.90


5 6 4 4 6 2 3 1 2 6

% decrease inavg negl. otlrs

2.0 1.9 1.5 1.9 2.8 2.3 0.8 1.6 0.4 3.4


1 0 1 4 3 2 0 1 0 2

Avg negloutside pts

23.60 12.66 17.80 13.36 13.17 9.49 29.77 12.05 30.63 20.28


1 0 1 4 3 2 0 1 0 3


0.5 0.0 0.5 1.9 1.9 2.3 0.0 1.6 0.0 1.5


0 0 0 0 0 1 0 1 0 0

Avg negloutside pts

23.71 12.66 17.89 13.62 13.42 9.58 29.77 12.05 30.63 20.59


0 0 0 0 0 1 0 1 0 0


0.0 0.0 0.0 0 0.0 1.3 0.0 1.6 0.0 0.0


0 0 0 0 0 1 0 1 0 0

Avg negloutside pts

23.71 12.66 17.89 13.62 13.42 9.58 29.77 12.05 30.63 20.59


0 0 0 0 0 1 0 1 0 0


0.0 0.0 0.0 0.0 0.0 1.3 0.0 1.6 0.0 0.0

B - 5

Table B-4. 1994-1998 Summary Data for the Worst Days (Light Extinction)Acadia Bandelier Big


LakeDenali Dolly

SodsGreatSandDunes

GreatSmokyMtns

PointReyes

# points 97 96 91 93 86 90 91 100 92 80

Mean 103.55 25.85 51.13 29.63 29.27 17.09 196.45 25.79 209.27 75.37

σ 44.73 5.68 14.25 7.88 10.09 7.87 70.33 21.34 50.82 43.83


5 7 4 4 5 2 6 1 3 5

Avg negloutside pts

95.92 24.72 48.89 28.30 27.32 16.11 184.03 23.73 204.85 66.14


5 7 4 4 6 2 7 1 3 6

% decrease inavg negl. tolrs

7.4 4.4 4.4 4.5 6.7 5.7 6.3 8.0 2.1 12.2


3 1 2 4 3 2 1 1 1 3

Avg negloutside pts

98.33 25.65 49.86 28.30 27.92 16.11 193.73 23.73 207.52 68.99


3 1 2 4 3 2 1 1 1 4


5.0 0.8 2.5 4.5 4.6 5.7 1.4 8.0 0.8 8.5


1 0 1 1 0 1 0 1 0 1

Avg negloutside pts

101.55 25.85 50.38 29.27 29.27 16.46 196.45 23.73 209.27 72.99


1 0 1 1 0 1 0 1 0 1


1.9 0.0 1.5 1.2 0.0 3.7 0.0 8.0 0.0 3.2


0 0 0 0 0 1 0 1 0 0

Avg negloutside pts

103.55 25.85 51.13 29.63 29.27 16.46 196.45 23.73 209.27 75.37


0 0 0 0 0 1 0 1 0 0


0.0 0.0 0.0 0.0 0.0 3.7 0.0 8.0 0.0 0.0

APPENDIX C.

Calculated Visibili ty Statistics for Individual Years

At Ten IMPROVE Sites

C - 2

Figure C-1. Effect of Outliers at Acadia IMPROVE Monitor for 2σ range (Deciviews).

Figure C-2. Effect of Outliers at Acadia IMPROVE Monitor for 2σ range (Light Extinction).

0

5

10

15

20

25

30

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Dec

ivie

ws

Worst Days Average Worst Days Average (minus outliers) Best Days Average Best Days Average (minus outliers)

0

20

40

60

80

100

120

140

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Aer

osol

Lig

ht E

xtin

ctio

n (M

m-1

)


C -

3

Tab

le C

-1.

Vis

ibili

ty D

ata

for

Aca

dia

IMP

RO

VE

Mon

itor

(D

eciv

iew

s).

DE

CIV

IEW

S19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s17

1718

1919

2019

1920

1958

5858

97m

ean

25.1

225

.72

24.9

124

.48

24.7

926

.01

22.9

723

.37

22.9

622

.56

24.2

023

.12

23.0

323

.71

σ2.

533.

012.

943.

442.

693.

052.

903.

352.

074.

423.

282.

753.

273.

27n

pts

ousi

de o

f 1 σ

66

54

84

44

55

1815

1730

n pt

s ou

side

of 2

σ0

01

21

11

20

13

34

5av

g ne

gl o

utsi

de p

ts25

.12

25.7

224

.49

23.5

724

.49

25.5

822

.62

22.3

722

.96

22.0

223

.74

22.6

922

.41

23.2

4n

pts

ousi

de o

f 3 σ

00

00

00

00

00

11

11

avg

negl

out

side

pts

25.1

225

.72

24.9

124

.48

24.7

926

.01

22.9

723

.37

22.9

622

.56

24.0

322

.94

22.8

623

.60

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts25

.12

25.7

224

.91

24.4

824

.79

26.0

122

.97

23.3

722

.96

22.5

624

.20

23.1

223

.03

23.7

1n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

25.1

225

.72

24.9

124

.48

24.7

926

.01

22.9

723

.37

22.9

622

.56

24.2

023

.12

23.0

323

.71

% o

f poi

nts

outs

ide

2 σ

00

611

55

511

05

55

75

% c

hang

e in

avg

neg

l. ot

lrs0.

00.

0-1

.7-3

.7-1

.2-1

.7-1

.5-4

.30.

0-2

.4-1

.9-1

.9-2

.7-2

.0B

est

Day

s#

pts

1717

1819

1920

1919

2019

5858

5897

mea

n10

.96

11.0

810

.96

10.0

110

.19

9.68

9.57

8.41

9.68

8.84

9.15

9.22

8.97

9.16

σ1.

971.

721.

451.

271.

612.

101.

281.

721.

221.

871.

691.

501.

651.

60n

pts

ousi

de o

f 1 σ

35

85

89

78

72

1917

1125

n pt

s ou

side

of 2

σ1

10

10

00

10

12

12

3av

g ne

gl o

utsi

de p

ts11

.24

11.3

310

.96

10.1

910

.19

9.68

9.57

8.67

9.68

9.16

9.31

9.32

9.16

9.32

n pt

s ou

side

of 3

σ0

00

00

00

00

11

12

2av

g ne

gl o

utsi

de p

ts10

.96

11.0

810

.96

10.0

110

.19

9.68

9.57

8.41

9.68

9.16

9.25

9.32

9.16

9.28

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts10

.96

11.0

810

.96

10.0

110

.19

9.68

9.57

8.41

9.68

8.84

9.15

9.22

8.97

9.16

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts10

.96

11.0

810

.96

10.0

110

.19

9.68

9.57

8.41

9.68

8.84

9.15

9.22

8.97

9.16

% o

f poi

nts

outs

ide

2 σ

66

05

00

05

05

32

33

% c

hang

e in

avg

neg

l. ot

lrs2.

62.

30.

01.

70.

00.

00.

03.

10.

03.

71.

71.

02.

21.

7

C -

4

Tab

le C

-2.

Vis

ibili

ty D

ata

for

Aca

dia

IMP

RO

VE

Mon

itor

(L

ight

Ext

inct

ion)

.L

IGH

T E

XT

INC

TIO

N19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s17

1718

1919

2019

1920

1958

5858

97m

ean

117.

1712

6.69

116.

2011

3.20

113.

5413

1.48

93.8

310

0.33

91.3

495

.80

109.

3895

.23

96.2

010

3.55

σ33

.24

42.7

941

.92

51.1

834

.55

51.0

233

.51

49.5

621

.10

55.1

247

.33

35.8

343

.13

44.7

3n

pts

ousi

de o

f 1 σ

65

22

73

32

54

76

613

n pt

s ou

side

of 2

σ1

11

21

11

21

14

34

5av

g ne

gl o

utsi

de p

ts11

2.47

120.

3610

8.93

98.2

210

8.97

122.

8589

.14

84.7

989

.00

87.5

299

.43

88.7

386

.75

95.9

2n

pts

ousi

de o

f 3 σ

00

00

01

01

00

22

23

avg

negl

out

side

pts

117.

1712

6.69

116.

2011

3.20

113.

5412

2.85

93.8

391

.42

91.3

495

.80

103.

3590

.33

90.6

198

.33

n pt

s ou

side

of 4

σ0

00

00

00

00

00

10

1av

g ne

gl o

utsi

de p

ts11

7.17

126.

6911

6.20

113.

2011

3.54

131.

4893

.83

100.

3391

.34

95.8

010

9.38

92.3

396

.20

101.

55n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

117.

1712

6.69

116.

2011

3.20

113.

5413

1.48

93.8

310

0.33

91.3

495

.80

109.

3895

.23

96.2

010

3.55

% o

f poi

nts

outs

ide

2 σ

66

611

55

511

55

75

75

% c

hang

e in

avg

neg

l. ot

lrs-4

.0-5

.0-6

.3-1

3.2

-4.0

-6.6

-5.0

-15.

5-2

.6-8

.6-9

.1-6

.8-9

.8-7

.4B

est

Day

s#

pts

1717

1819

1920

1919

2019

5858

5897

mea

n20

.44

20.6

720

.23

17.4

118

.04

16.8

716

.25

13.5

116

.52

14.5

715

.32

15.4

114

.82

15.3

0σ

5.39

4.88

4.29

3.24

4.30

5.50

3.23

3.75

3.13

3.98

4.06

3.54

3.68

3.73

n pt

s ou

side

of 1

σ3

59

58

97

87

521

1817

29n

pts

ousi

de o

f 2 σ

11

01

00

01

01

11

23

avg

negl

out

side

pts

21.1

521

.33

20.2

317

.83

18.0

416

.87

16.2

514

.00

16.5

215

.18

15.5

115

.60

15.2

015

.62

n pt

s ou

side

of 3

σ0

00

00

00

00

00

11

1av

g ne

gl o

utsi

de p

ts20

.44

20.6

720

.23

17.4

118

.04

16.8

716

.25

13.5

116

.52

14.5

715

.32

15.6

015

.02

15.4

2n

pts

ousi

de o

f 4 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

20.4

420

.67

20.2

317

.41

18.0

416

.87

16.2

513

.51

16.5

214

.57

15.3

215

.41

14.8

215

.30

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts20

.44

20.6

720

.23

17.4

118

.04

16.8

716

.25

13.5

116

.52

14.5

715

.32

15.4

114

.82

15.3

0%

of p

oint

s ou

tsid

e 2

σ6

60

50

00

50

52

23

3%

cha

nge

in a

vg n

egl.

otlrs

3.5

3.2

0.0

2.4

0.0

0.0

0.0

3.7

0.0

4.2

1.2

1.2

2.6

2.1

C - 5

Figure C-3. Effect of Outliers at Bandelier IMPROVE Monitor for 2σ range (Deciviews).

Figure C-4. Effect of Outliers at Bandelier IMPROVE Monitor for 2σ range (Light Extinction).

0

2

4

6

8

10

12

14

16

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Dec

ivie

ws


0

5

10

15

20

25

30

35

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Aer

osol

Lig

ht E

xtin

ctio

n (M

m-1

)


C-6

Tab

le C

-3.

Vis

ibili

ty D

ata

for

Ban

deli

er I

MP

RO

VE

Mon

itor

(D

eciv

iew

s).

DE

CIV

IEW

S19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s16

1515

1519

1817

1920

1955

5759

96m

ean

14.0

413

.85

12.1

813

.07

12.6

812

.18

12.6

812

.31

12.5

113

.64

12.3

612

.47

12.8

312

.66

σ1.

151.

100.

941.

371.

401.

061.

521.

251.

521.

691.

271.

411.

541.

46n

pts

ousi

de o

f 1 σ

55

53

52

64

36

1515

1321

n pt

s ou

side

of 2

σ1

11

10

21

12

03

43

6av

g ne

gl o

utsi

de p

ts13

.85

13.6

912

.02

12.8

012

.68

11.8

712

.47

12.1

312

.12

13.6

412

.18

12.2

112

.63

12.4

2n

pts

ousi

de o

f 3 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

14.0

413

.85

12.1

813

.07

12.6

812

.18

12.6

812

.31

12.5

113

.64

12.3

612

.47

12.8

312

.66

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts14

.04

13.8

512

.18

13.0

712

.68

12.1

812

.68

12.3

112

.51

13.6

412

.36

12.4

712

.83

12.6

6n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

14.0

413

.85

12.1

813

.07

12.6

812

.18

12.6

812

.31

12.5

113

.64

12.3

612

.47

12.8

312

.66

% o

f poi

nts

outs

ide

2 σ

67

77

011

65

100

57

56

% c

hang

e in

avg

neg

l. ot

lrs-1

.3-1

.2-1

.3-2

.10.

0-2

.6-1

.6-1

.4-3

.10.

0-1

.5-2

.1-1

.6-1

.9B

est

Day

s#

pts

1615

1515

1918

1719

2019

5557

5996

mea

n6.

476.

986.

606.

746.

836.

485.

585.

615.

876.

605.

855.

696.

006.

01σ

1.32

0.97

1.31

0.78

1.02

0.98

0.81

0.80

0.94

1.15

0.89

0.82

1.00

0.97

n pt

s ou

side

of 1

σ3

35

65

15

107

317

2220

28n

pts

ousi

de o

f 2 σ

10

10

01

10

02

22

24

avg

negl

out

side

pts

6.71

6.98

6.82

6.74

6.83

6.67

5.72

5.61

5.87

6.94

5.95

5.76

6.08

6.12

n pt

s ou

side

of 3

σ0

00

00

10

00

01

00

0av

g ne

gl o

utsi

de p

ts6.

476.

986.

606.

746.

836.

675.

585.

615.

876.

605.

905.

696.

006.

01n

pts

ousi

de o

f 4 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

6.47

6.98

6.60

6.74

6.83

6.48

5.58

5.61

5.87

6.60

5.85

5.69

6.00

6.01

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts6.

476.

986.

606.

746.

836.

485.

585.

615.

876.

605.

855.

696.

006.

01%

of p

oint

s ou

tsid

e 2

σ6

07

00

66

00

114

43

4%

cha

nge

in a

vg n

egl.

otlrs

3.6

0.0

3.4

0.0

0.0

3.0

2.4

0.0

0.0

5.1

1.6

1.3

1.4

1.8

C-7

Tab

le C

-4.

Vis

ibili

ty D

ata

for

Ban

deli

er I

MP

RO

VE

Mon

itor

(L

ight

Ext

inct

ion)

.L

IGH

T E

XT

INC

TIO

N19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s16

1515

1519

1817

1920

1955

5759

96m

ean

30.9

830

.18

23.9

427

.30

25.8

724

.00

25.9

224

.50

25.3

629

.67

24.7

225

.16

26.5

425

.85

σ4.

914.

613.

335.

665.

223.

895.

704.

635.

877.

044.

725.

346.

115.

68n

pts

ousi

de o

f 1 σ

55

41

52

43

35

87

915

n pt

s ou

side

of 2

σ1

11

11

21

12

13

44

7av

g ne

gl o

utsi

de p

ts30

.10

29.4

823

.35

26.1

025

.26

22.8

225

.07

23.8

023

.77

28.8

623

.99

24.1

225

.44

24.7

2n

pts

ousi

de o

f 3 σ

00

00

00

00

00

10

01

avg

negl

out

side

pts

30.9

830

.18

23.9

427

.30

25.8

724

.00

25.9

224

.50

25.3

629

.67

24.4

425

.16

26.5

425

.65

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts30

.98

30.1

823

.94

27.3

025

.87

24.0

025

.92

24.5

025

.36

29.6

724

.72

25.1

626

.54

25.8

5n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

30.9

830

.18

23.9

427

.30

25.8

724

.00

25.9

224

.50

25.3

629

.67

24.7

225

.16

26.5

425

.85

% o

f poi

nts

outs

ide

2 σ

67

77

511

65

105

57

77

% c

hang

e in

avg

neg

l. ot

lrs-2

.8-2

.3-2

.5-4

.4-2

.4-4

.9-3

.3-2

.9-6

.2-2

.7-3

.0-4

.1-4

.1-4

.4B

est

Day

s#

pts

1615

1515

1918

1719

2019

5557

5996

mea

n9.

2510

.19

9.49

9.68

9.89

9.19

7.53

7.57

8.05

9.46

8.02

7.72

8.30

8.31

σ2.

351.

902.

441.

501.

951.

691.

351.

421.

652.

021.

531.

431.

761.

69n

pts

ousi

de o

f 1 σ

44

66

72

610

73

1924

2029

n pt

s ou

side

of 2

σ1

01

00

11

00

22

11

4av

g ne

gl o

utsi

de p

ts9.

6410

.19

9.87

9.68

9.89

9.51

7.74

7.57

8.05

10.0

48.

187.

798.

388.

50n

pts

ousi

de o

f 3 σ

00

00

01

00

00

00

00

avg

negl

out

side

pts

9.25

10.1

99.

499.

689.

899.

517.

537.

578.

059.

468.

027.

728.

308.

31n

pts

ousi

de o

f 4 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

9.25

10.1

99.

499.

689.

899.

197.

537.

578.

059.

468.

027.

728.

308.

31n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

9.25

10.1

99.

499.

689.

899.

197.

537.

578.

059.

468.

027.

728.

308.

31%

of p

oint

s ou

tsid

e 2

σ6

07

00

66

00

114

22

4%

cha

nge

in a

vg n

egl.

otlrs

4.2

0.0

4.0

0.0

0.0

3.5

2.9

0.0

0.0

6.1

1.9

0.8

0.9

2.2

C-8

Figure C-5. Effect of Outliers at Big Bend IMPROVE Monitor for 2σ range (Deciviews).

Figure C-6. Effect of Outliers at Big Bend IMPROVE Monitor for 2σ range (Light Extinction).

0

5

10

15

20

25

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Dec

ivie

ws


0

10

20

30

40

50

60

70

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Aer

osol

Lig

ht E

xtin

ctio

n (M

m-1

)


C-9

Tab

le C

-5.

Vis

ibili

ty D

ata

for

Big

Ben

d IM

PR

OV

E M

onit

or (

Dec

ivie

ws)

.D

EC

IVIE

WS

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1994

-199

619

95-1

997

1996

-199

819

94-1

998

Wo

rst

Day

s#

pts

1516

1920

1919

1814

2019

5252

5391

mea

n16

.17

16.3

116

.89

16.3

716

.45

17.2

517

.38

18.2

417

.06

19.5

217

.54

17.5

318

.33

17.8

9σ

1.58

1.78

1.34

1.80

1.28

1.49

1.42

2.25

1.77

2.30

1.72

1.79

2.23

2.00

n pt

s ou

side

of 1

σ5

63

43

55

37

514

1514

24n

pts

ousi

de o

f 2 σ

10

11

12

11

11

34

44

avg

negl

out

side

pts

15.9

016

.31

16.6

716

.13

16.2

316

.87

17.1

517

.86

16.8

219

.18

17.2

717

.17

17.8

717

.61

n pt

s ou

side

of 3

σ0

00

01

00

00

01

11

1av

g ne

gl o

utsi

de p

ts16

.17

16.3

116

.89

16.3

716

.23

17.2

517

.38

18.2

417

.06

19.5

217

.43

17.4

218

.19

17.8

0n

pts

ousi

de o

f 4 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

16.1

716

.31

16.8

916

.37

16.4

517

.25

17.3

818

.24

17.0

619

.52

17.5

417

.53

18.3

317

.89

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts16

.17

16.3

116

.89

16.3

716

.45

17.2

517

.38

18.2

417

.06

19.5

217

.54

17.5

318

.33

17.8

9%

of p

oint

s ou

tsid

e 2

σ7

05

55

116

75

56

88

4%

cha

nge

in a

vg n

egl.

otlrs

-1.6

0.0

-1.3

-1.5

-1.3

-2.2

-1.3

-2.1

-1.4

-1.7

-1.5

-2.1

-2.5

-1.5

Bes

t D

ays

# pt

s15

1619

2019

1918

1420

1952

5253

91m

ean

7.54

8.25

7.61

7.28

7.10

8.06

7.30

8.46

6.65

8.87

7.90

7.20

7.69

7.70

σ1.

710.

781.

041.

311.

661.

671.

661.

631.

121.

491.

651.

401.

461.

54n

pts

ousi

de o

f 1 σ

26

93

76

53

55

2019

2034

n pt

s ou

side

of 2

σ1

00

20

02

12

12

42

4av

g ne

gl o

utsi

de p

ts7.

868.

257.

617.

647.

108.

067.

748.

726.

929.

058.

067.

477.

827.

87n

pts

ousi

de o

f 3 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

7.54

8.25

7.61

7.28

7.10

8.06

7.30

8.46

6.65

8.87

7.90

7.20

7.69

7.70

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts7.

548.

257.

617.

287.

108.

067.

308.

466.

658.

877.

907.

207.

697.

70n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

7.54

8.25

7.61

7.28

7.10

8.06

7.30

8.46

6.65

8.87

7.90

7.20

7.69

7.70

% o

f poi

nts

outs

ide

2 σ

70

010

00

117

105

48

44

% c

hang

e in

avg

neg

l. ot

lrs4.

30.

00.

05.

00.

00.

05.

93.

14.

11.

92.

13.

71.

82.

2

C-1

0

Tab

le C

-6.

Vis

ibili

ty D

ata

for

Big

Ben

d IM

PR

OV

E M

onit

or (

Lig

ht E

xtin

ctio

n).

LIG

HT

EX

TIN

CT

ION

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1994

-199

619

95-1

997

1996

-199

819

94-1

998

Wo

rst

Day

s#

pts

1516

1920

1919

1814

2019

5252

5391

mea

n40

.99

41.8

744

.63

42.2

242

.24

46.7

747

.43

53.5

245

.94

62.3

948

.67

48.6

754

.19

51.1

3σ

8.60

9.21

7.95

10.2

37.

509.

098.

8515

.58

10.7

219

.44

11.2

811

.68

16.5

214

.25

n pt

s ou

side

of 1

σ2

63

22

43

26

38

77

10n

pts

ousi

de o

f 2 σ

10

11

12

11

11

34

44

avg

negl

out

side

pts

39.4

141

.87

43.1

940

.71

40.8

744

.31

45.8

850

.62

44.3

259

.25

46.7

746

.14

50.4

748

.89

n pt

s ou

side

of 3

σ0

01

01

00

00

01

11

2av

g ne

gl o

utsi

de p

ts40

.99

41.8

743

.19

42.2

240

.87

46.7

747

.43

53.5

245

.94

62.3

947

.84

47.8

452

.94

49.8

6n

pts

ousi

de o

f 4 σ

00

00

00

00

00

00

01

avg

negl

out

side

pts

40.9

941

.87

44.6

342

.22

42.2

446

.77

47.4

353

.52

45.9

462

.39

48.6

748

.67

54.1

950

.38

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts40

.99

41.8

744

.63

42.2

242

.24

46.7

747

.43

53.5

245

.94

62.3

948

.67

48.6

754

.19

51.1

3%

of p

oint

s ou

tsid

e 2

σ7

05

55

116

75

56

88

4%

cha

nge

in a

vg n

egl.

otlrs

-3.9

0.0

-3.2

-3.6

-3.2

-5.3

-3.3

-5.4

-3.5

-5.0

-3.9

-5.2

-6.9

-4.4

Bes

t D

ays

# pt

s15

1619

2019

1918

1420

1952

5253

91m

ean

11.5

212

.88

11.5

110

.86

10.6

012

.68

11.0

213

.57

9.55

14.5

412

.32

10.7

411

.79

11.8

4σ

3.33

1.78

2.22

2.47

3.22

3.58

3.27

3.65

2.08

3.43

3.47

2.77

3.08

3.21

n pt

s ou

side

of 1

σ4

69

48

87

46

621

2020

37n

pts

ousi

de o

f 2 σ

10

02

00

00

20

22

24

avg

negl

out

side

pts

12.0

912

.88

11.5

111

.52

10.6

012

.68

11.0

213

.57

10.0

314

.54

12.6

210

.99

12.0

512

.16

n pt

s ou

side

of 3

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts11

.52

12.8

811

.51

10.8

610

.60

12.6

811

.02

13.5

79.

5514

.54

12.3

210

.74

11.7

911

.84

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts11

.52

12.8

811

.51

10.8

610

.60

12.6

811

.02

13.5

79.

5514

.54

12.3

210

.74

11.7

911

.84

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts11

.52

12.8

811

.51

10.8

610

.60

12.6

811

.02

13.5

79.

5514

.54

12.3

210

.74

11.7

911

.84

% o

f poi

nts

outs

ide

2 σ

70

010

00

00

100

44

44

% c

hang

e in

avg

neg

l. ot

lrs5.

00.

00.

06.

10.

00.

00.

00.

05.

00.

02.

52.

32.

22.

7

C-11

Figure C-7. Effect of Outliers at Chiricahua IMPROVE Monitor for 2σ range (Deciviews).

Figure C-8. Effect of Outliers at Chiricahua IMPROVE Monitor for 2σ range (Light Extinction).

0

2

4

6

8

10

12

14

16

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Dec

ivie

ws


0

5

10

15

20

25

30

35

40

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Aer

osol

Lig

ht E

xtin

ctio

n (M

m-1

)


C-1

2

Tab

le C

-7.

Vis

ibili

ty D

ata

for

Chi

rica

hua

IMP

RO

VE

Mon

itor

(D

eciv

iew

s).

DE

CIV

IEW

S19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s11

1617

1818

1917

1920

1756

5756

93m

ean

13.5

714

.25

12.9

612

.74

13.5

113

.68

13.7

113

.26

12.5

514

.77

13.5

513

.17

13.5

613

.62

σ2.

001.

490.

502.

061.

431.

741.

900.

851.

262.

201.

501.

381.

641.

67n

pts

ousi

de o

f 1 σ

25

41

13

53

72

814

813

n pt

s ou

side

of 2

σ1

10

11

11

10

23

22

4av

g ne

gl o

utsi

de p

ts13

.11

14.0

212

.96

12.2

813

.21

13.3

813

.39

13.1

312

.55

14.1

013

.28

13.0

013

.33

13.3

6n

pts

ousi

de o

f 3 σ

00

01

11

00

00

21

24

avg

negl

out

side

pts

13.5

714

.25

12.9

612

.28

13.2

113

.38

13.7

113

.26

12.5

514

.77

13.3

513

.07

13.3

313

.36

n pt

s ou

side

of 4

σ0

00

00

00

00

00

10

0av

g ne

gl o

utsi

de p

ts13

.57

14.2

512

.96

12.7

413

.51

13.6

813

.71

13.2

612

.55

14.7

713

.55

13.0

713

.56

13.6

2n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

13.5

714

.25

12.9

612

.74

13.5

113

.68

13.7

113

.26

12.5

514

.77

13.5

513

.17

13.5

613

.62

% o

f poi

nts

outs

ide

2 σ

96

06

65

65

012

54

44

% c

hang

e in

avg

neg

l. ot

lrs-3

.4-1

.60.

0-3

.6-2

.2-2

.2-2

.3-1

.00.

0-4

.5-2

.0-1

.3-1

.7-1

.9B

est

Day

s#

pts

1116

1718

1819

1719

2017

5657

5693

mea

n5.

186.

016.

426.

185.

876.

476.

276.

036.

426.

076.

286.

266.

186.

27σ

1.00

0.87

1.21

0.89

0.83

1.10

0.99

0.87

1.22

1.18

0.99

1.04

1.09

1.07

n pt

s ou

side

of 1

σ5

34

85

57

75

320

2218

32n

pts

ousi

de o

f 2 σ

11

10

11

00

21

12

34

avg

negl

out

side

pts

5.40

6.15

6.63

6.18

5.99

6.63

6.27

6.03

6.71

6.30

6.32

6.35

6.34

6.40

n pt

s ou

side

of 3

σ0

00

00

00

00

10

01

1av

g ne

gl o

utsi

de p

ts5.

186.

016.

426.

185.

876.

476.

276.

036.

426.

306.

286.

266.

256.

31n

pts

ousi

de o

f 4 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

5.18

6.01

6.42

6.18

5.87

6.47

6.27

6.03

6.42

6.07

6.28

6.26

6.18

6.27

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts5.

186.

016.

426.

185.

876.

476.

276.

036.

426.

076.

286.

266.

186.

27%

of p

oint

s ou

tsid

e 2

σ9

66

06

50

010

62

45

4%

cha

nge

in a

vg n

egl.

otlrs

4.2

2.4

3.3

0.0

2.1

2.3

0.0

0.0

4.5

3.8

0.7

1.4

2.6

2.0

C-1

3

Tab

le C

-8.

Vis

ibili

ty D

ata

for

Chi

rica

hua

IMP

RO

VE

Mon

itor

(L

ight

Ext

inct

ion)

.L

IGH

T E

XT

INC

TIO

N19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s11

1617

1818

1917

1920

1756

5756

93m

ean

29.5

932

.01

26.6

026

.66

29.0

229

.91

30.1

127

.80

25.3

634

.91

29.2

527

.69

29.3

929

.63

σ8.

746.

581.

8310

.64

6.73

8.19

8.63

3.39

4.60

11.4

26.

915.

897.

817.

88n

pts

ousi

de o

f 1 σ

15

41

12

23

52

77

59

n pt

s ou

side

of 2

σ1

11

11

11

10

23

22

4av

g ne

gl o

utsi

de p

ts27

.42

30.9

326

.37

24.2

027

.55

28.3

828

.52

27.2

525

.36

31.2

727

.94

26.8

828

.17

28.3

0n

pts

ousi

de o

f 3 σ

00

01

11

00

00

21

24

avg

negl

out

side

pts

29.5

932

.01

26.6

024

.20

27.5

528

.38

30.1

127

.80

25.3

634

.91

28.2

427

.19

28.1

728

.30

n pt

s ou

side

of 4

σ0

00

00

00

00

01

12

1av

g ne

gl o

utsi

de p

ts29

.59

32.0

126

.60

26.6

629

.02

29.9

130

.11

27.8

025

.36

34.9

128

.74

27.1

928

.17

29.2

7n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

29.5

932

.01

26.6

026

.66

29.0

229

.91

30.1

127

.80

25.3

634

.91

29.2

527

.69

29.3

929

.63

% o

f poi

nts

outs

ide

2 σ

96

66

65

65

012

54

44

% c

hang

e in

avg

neg

l. ot

lrs-7

.3-3

.4-0

.9-9

.2-5

.1-5

.1-5

.3-2

.00.

0-1

0.4

-4.5

-2.9

-4.1

-4.5

Bes

t D

ays

# pt

s11

1617

1818

1917

1920

1756

5756

93m

ean

6.86

8.30

9.12

8.62

8.04

9.21

8.80

8.34

9.13

8.46

8.82

8.81

8.65

8.82

σ1.

631.

532.

161.

641.

462.

021.

851.

562.

211.

971.

831.

901.

921.

92n

pts

ousi

de o

f 1 σ

53

58

55

78

63

2022

1832

n pt

s ou

side

of 2

σ1

11

01

10

02

11

23

4av

g ne

gl o

utsi

de p

ts7.

208.

549.

478.

628.

249.

478.

808.

349.

638.

828.

908.

968.

929.

03n

pts

ousi

de o

f 3 σ

00

00

00

00

00

00

11

avg

negl

out

side

pts

6.86

8.30

9.12

8.62

8.04

9.21

8.80

8.34

9.13

8.46

8.82

8.81

8.76

8.89

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts6.

868.

309.

128.

628.

049.

218.

808.

349.

138.

468.

828.

818.

658.

82n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

6.86

8.30

9.12

8.62

8.04

9.21

8.80

8.34

9.13

8.46

8.82

8.81

8.65

8.82

% o

f poi

nts

outs

ide

2 σ

96

60

65

00

106

24

54

% c

hang

e in

avg

neg

l. ot

lrs4.

92.

93.

80.

02.

52.

80.

00.

05.

54.

20.

91.

73.

02.

4

C-14

Figure C-9. Effect of Outliers at Crater Lake IMPROVE Monitor for 2σ range (Deciviews).

Figure C-10. Effect of Outliers at Crater Lake IMPROVE Monitor for 2σ range (LightExtinction).

0

2

4

6

8

10

12

14

16

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Dec

ivie

ws


0

5

10

15

20

25

30

35

40

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Aer

osol

Lig

ht E

xtin

ctio

n (M

m-1

)


C-1

5

Tab

le C

-9.

Vis

ibili

ty D

ata

for

Cra

ter

Lak

e IM

PR

OV

E M

onit

or (

Dec

ivie

ws)

.D

EC

IVIE

WS

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1994

-199

619

95-1

997

1996

-199

819

94-1

998

Wo

rst

Day

s#

pts

811

1118

1713

1918

1717

5155

5386

mea

n14

.09

14.4

413

.42

13.9

714

.30

15.1

412

.57

14.8

711

.66

12.8

914

.12

13.0

913

.20

13.4

2σ

1.19

1.81

1.60

2.41

2.48

1.73

1.26

2.60

1.33

2.35

2.14

2.18

2.46

2.19

n pt

s ou

side

of 1

σ2

43

23

47

53

212

1411

24n

pts

ousi

de o

f 2 σ

10

12

10

02

11

33

45

avg

negl

out

side

pts

13.7

314

.44

13.0

513

.24

13.8

215

.14

12.5

714

.17

11.4

612

.44

13.7

612

.71

12.6

613

.04

n pt

s ou

side

of 3

σ0

00

01

00

00

11

21

3av

g ne

gl o

utsi

de p

ts14

.09

14.4

413

.42

13.9

713

.82

15.1

412

.57

14.8

711

.66

12.4

413

.99

12.8

113

.06

13.1

7n

pts

ousi

de o

f 4 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

14.0

914

.44

13.4

213

.97

14.3

015

.14

12.5

714

.87

11.6

612

.89

14.1

213

.09

13.2

013

.42

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts14

.09

14.4

413

.42

13.9

714

.30

15.1

412

.57

14.8

711

.66

12.8

914

.12

13.0

913

.20

13.4

2%

of p

oint

s ou

tsid

e 2

σ13

09

116

00

116

66

58

6%

cha

nge

in a

vg n

egl.

otlrs

-2.6

0.0

-2.8

-5.2

-3.4

0.0

0.0

-4.7

-1.7

-3.5

-2.5

-2.9

-4.1

-2.8

Bes

t D

ays

# pt

s8

1111

1817

1319

1817

1751

5553

86m

ean

3.91

5.94

5.05

5.10

4.48

3.25

3.21

3.86

3.96

3.51

3.45

3.66

3.77

3.57

σ0.

990.

711.

290.

920.

991.

020.

750.

831.

030.

800.

860.

890.

870.

88n

pts

ousi

de o

f 1 σ

25

46

36

66

54

2119

1731

n pt

s ou

side

of 2

σ0

00

01

00

11

11

22

3av

g ne

gl o

utsi

de p

ts3.

915.

945.

055.

104.

633.

253.

213.

964.

093.

643.

493.

733.

863.

64n

pts

ousi

de o

f 3 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

3.91

5.94

5.05

5.10

4.48

3.25

3.21

3.86

3.96

3.51

3.45

3.66

3.77

3.57

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts3.

915.

945.

055.

104.

483.

253.

213.

863.

963.

513.

453.

663.

773.

57n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

3.91

5.94

5.05

5.10

4.48

3.25

3.21

3.86

3.96

3.51

3.45

3.66

3.77

3.57

% o

f poi

nts

outs

ide

2 σ

00

00

60

06

66

24

43

% c

hang

e in

avg

neg

l. ot

lrs0.

00.

00.

00.

03.

30.

00.

02.

63.

43.

71.

11.

92.

22.

0

C-1

6

Tab

le C

-10.

Vis

ibili

ty D

ata

for

Cra

ter

Lak

e IM

PR

OV

E M

onit

or (

Lig

ht E

xtin

ctio

n).

LIG

HT

EX

TIN

CT

ION

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1994

-199

619

95-1

997

1996

-199

819

94-1

998

Wo

rst

Day

s#

pts

811

1118

1713

1918

1717

5155

5386

mea

n31

.21

33.0

528

.75

31.7

033

.18

36.1

025

.43

35.7

922

.36

27.3

932

.05

28.0

028

.70

29.2

7σ

5.28

8.22

6.77

12.1

113

.49

8.09

4.52

13.5

74.

6410

.91

10.3

510

.07

11.5

110

.09

n pt

s ou

side

of 1

σ1

32

21

47

33

27

54

10n

pts

ousi

de o

f 2 σ

10

12

11

02

11

33

35

avg

negl

out

side

pts

29.5

333

.05

27.0

527

.84

30.2

634

.69

25.4

331

.84

21.6

325

.07

30.1

426

.03

26.4

427

.32

n pt

s ou

side

of 3

σ0

00

01

00

00

12

23

3av

g ne

gl o

utsi

de p

ts31

.21

33.0

528

.75

31.7

030

.26

36.1

025

.43

35.7

922

.36

25.0

730

.61

26.5

226

.44

27.9

2n

pts

ousi

de o

f 4 σ

00

00

00

00

00

01

00

avg

negl

out

side

pts

31.2

133

.05

28.7

531

.70

33.1

836

.10

25.4

335

.79

22.3

627

.39

32.0

527

.25

28.7

029

.27

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts31

.21

33.0

528

.75

31.7

033

.18

36.1

025

.43

35.7

922

.36

27.3

932

.05

28.0

028

.70

29.2

7%

of p

oint

s ou

tsid

e 2

σ13

09

116

80

116

66

56

6%

cha

nge

in a

vg n

egl.

otlrs

-5.4

0.0

-5.9

-12.

2-8

.8-3

.90.

0-1

1.0

-3.3

-8.5

-6.0

-7.0

-7.9

-6.7

Bes

t D

ays

# pt

s8

1111

1817

1319

1817

1751

5553

86m

ean

4.85

8.15

6.70

6.73

5.72

3.90

3.82

4.76

4.93

4.25

4.17

4.47

4.63

4.34

σ1.

421.

292.

181.

481.

461.

411.

011.

221.

461.

101.

201.

271.

231.

24n

pts

ousi

de o

f 1 σ

35

46

36

66

56

2219

2033

n pt

s ou

side

of 2

σ0

00

01

00

01

11

02

2av

g ne

gl o

utsi

de p

ts4.

858.

156.

706.

735.

933.

903.

824.

765.

114.

424.

224.

474.

754.

40n

pts

ousi

de o

f 3 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

4.85

8.15

6.70

6.73

5.72

3.90

3.82

4.76

4.93

4.25

4.17

4.47

4.63

4.34

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts4.

858.

156.

706.

735.

723.

903.

824.

764.

934.

254.

174.

474.

634.

34n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

4.85

8.15

6.70

6.73

5.72

3.90

3.82

4.76

4.93

4.25

4.17

4.47

4.63

4.34

% o

f poi

nts

outs

ide

2 σ

00

00

60

00

66

20

42

% c

hang

e in

avg

neg

l. ot

lrs0.

00.

00.

00.

03.

60.

00.

00.

03.

84.

01.

20.

02.

41.

5

C-17

Figure C-11. Effect of Outliers at Denali IMPROVE Monitor for 2σ range (Deciviews).

Figure C-12. Effect of Outliers at Denali IMPROVE Monitor for 2σ range (Light Extinction).

0

2

4

6

8

10

12

14

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Dec

ivie

ws


0

5

10

15

20

25

30

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Aer

osol

Lig

ht E

xtin

ctio

n (M

m-1

)


C-1

8

Tab

le C

-11.

Vis

ibili

ty D

ata

for

Den

ali

IMP

RO

VE

Mon

itor

(D

eciv

iew

s).

DE

CIV

IEW

S19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s17

1415

1718

1817

1817

1754

5353

90m

ean

10.4

712

.84

12.0

19.

4810

.95

10.3

69.

659.

3211

.12

7.93

9.76

10.0

09.

559.

71σ

1.30

2.06

2.67

0.90

2.59

1.81

1.11

1.25

3.36

0.83

1.46

2.23

2.33

2.03

n pt

s ou

side

of 1

σ5

42

46

77

52

716

45

10n

pts

ousi

de o

f 2 σ

11

11

00

11

10

42

22

avg

negl

out

side

pts

10.3

012

.47

11.5

99.

3310

.95

10.3

69.

499.

1210

.49

7.93

9.49

9.63

9.16

9.49

n pt

s ou

side

of 3

σ0

00

00

00

00

00

22

2av

g ne

gl o

utsi

de p

ts10

.47

12.8

412

.01

9.48

10.9

510

.36

9.65

9.32

11.1

27.

939.

769.

639.

169.

49n

pts

ousi

de o

f 4 σ

00

00

00

00

00

01

11

avg

negl

out

side

pts

10.4

712

.84

12.0

19.

4810

.95

10.3

69.

659.

3211

.12

7.93

9.76

9.78

9.32

9.58

n pt

s ou

side

of 5

σ0

00

00

00

00

00

10

1av

g ne

gl o

utsi

de p

ts10

.47

12.8

412

.01

9.48

10.9

510

.36

9.65

9.32

11.1

27.

939.

769.

789.

559.

58%

of p

oint

s ou

tsid

e 2

σ6

77

60

06

66

07

44

2%

cha

nge

in a

vg n

egl.

otlrs

-1.7

-2.8

-3.4

-1.6

0.0

0.0

-1.6

-2.1

-5.7

0.0

-2.8

-3.7

-4.0

-2.3

Bes

t D

ays

# pt

s17

1415

1718

1817

1817

1754

5353

90m

ean

3.14

4.70

3.35

3.29

3.16

3.18

2.91

3.17

3.46

2.57

3.08

3.15

3.02

3.04

σ0.

751.

190.

570.

630.

380.

700.

560.

580.

870.

460.

580.

650.

660.

63n

pts

ousi

de o

f 1 σ

82

25

86

57

58

2219

2136

n pt

s ou

side

of 2

σ0

11

10

00

11

01

11

2av

g ne

gl o

utsi

de p

ts3.

144.

913.

443.

383.

163.

182.

913.

253.

592.

573.

103.

183.

063.

07n

pts

ousi

de o

f 3 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

3.14

4.70

3.35

3.29

3.16

3.18

2.91

3.17

3.46

2.57

3.08

3.15

3.02

3.04

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts3.

144.

703.

353.

293.

163.

182.

913.

173.

462.

573.

083.

153.

023.

04n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

3.14

4.70

3.35

3.29

3.16

3.18

2.91

3.17

3.46

2.57

3.08

3.15

3.02

3.04

% o

f poi

nts

outs

ide

2 σ

07

76

00

06

60

22

22

% c

hang

e in

avg

neg

l. ot

lrs0.

04.

42.

62.

50.

00.

00.

02.

43.

80.

00.

71.

11.

01.

1

C-1

9

Tab

le C

-12.

Vis

ibili

ty D

ata

for

Den

ali

IMP

RO

VE

Mon

itor

(L

ight

Ext

inct

ion)

.L

IGH

T E

XT

INC

TIO

N19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s17

1415

1718

1817

1817

1754

5353

90m

ean

18.7

226

.88

24.4

315

.92

20.9

018

.62

16.4

015

.59

22.5

012

.16

16.8

218

.05

16.9

117

.09

σ3.

898.

5110

.17

2.44

8.61

5.36

3.05

3.46

15.3

01.

874.

219.

409.

637.

87n

pts

ousi

de o

f 1 σ

53

24

46

53

27

112

27

n pt

s ou

side

of 2

σ1

11

11

01

11

14

22

2av

g ne

gl o

utsi

de p

ts18

.17

25.2

622

.66

15.4

819

.89

18.6

215

.94

15.0

019

.33

11.9

215

.99

16.3

915

.20

16.1

1n

pts

ousi

de o

f 3 σ

00

00

00

00

10

02

22

avg

negl

out

side

pts

18.7

226

.88

24.4

315

.92

20.9

018

.62

16.4

015

.59

19.3

312

.16

16.8

216

.39

15.2

016

.11

n pt

s ou

side

of 4

σ0

00

00

00

00

00

11

1av

g ne

gl o

utsi

de p

ts18

.72

26.8

824

.43

15.9

220

.90

18.6

216

.40

15.5

922

.50

12.1

616

.82

16.9

915

.82

16.4

6n

pts

ousi

de o

f 5 σ

00

00

00

00

00

01

11

avg

negl

out

side

pts

18.7

226

.88

24.4

315

.92

20.9

018

.62

16.4

015

.59

22.5

012

.16

16.8

216

.99

15.8

216

.46

% o

f poi

nts

outs

ide

2 σ

67

76

60

66

66

74

42

% c

hang

e in

avg

neg

l. ot

lrs-3

.0-6

.0-7

.3-2

.8-4

.90.

0-2

.8-3

.8-1

4.1

-2.0

-4.9

-9.2

-10.

1-5

.7B

est

Day

s#

pts

1714

1517

1818

1718

1717

5453

5390

mea

n3.

726.

104.

013.

933.

733.

783.

403.

764.

192.

953.

633.

733.

563.

57σ

1.03

1.81

0.78

0.85

0.52

0.95

0.75

0.79

1.19

0.58

0.78

0.87

0.88

0.85

n pt

s ou

side

of 1

σ8

32

58

65

75

822

2121

36n

pts

ousi

de o

f 2 σ

01

11

00

01

10

01

11

avg

negl

out

side

pts

3.72

6.40

4.12

4.04

3.73

3.78

3.40

3.85

4.36

2.95

3.63

3.77

3.60

3.60

n pt

s ou

side

of 3

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts3.

726.

104.

013.

933.

733.

783.

403.

764.

192.

953.

633.

733.

563.

57n

pts

ousi

de o

f 4 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

3.72

6.10

4.01

3.93

3.73

3.78

3.40

3.76

4.19

2.95

3.63

3.73

3.56

3.57

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts3.

726.

104.

013.

933.

733.

783.

403.

764.

192.

953.

633.

733.

563.

57%

of p

oint

s ou

tsid

e 2

σ0

77

60

00

66

00

22

1%

cha

nge

in a

vg n

egl.

otlrs

0.0

4.9

2.9

2.8

0.0

0.0

0.0

2.6

4.0

0.0

0.0

1.2

1.1

0.7

C-20

Figure C-13. Effect of Outliers at Dolly Sods IMPROVE Monitor for 2σ range (Deciviews).

Figure C-14. Effect of Outliers at Dolly Sods IMPROVE Monitor for 2σ range (LightExtinction).

0

5

10

15

20

25

30

35

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Dec

ivie

ws


0

50

100

150

200

250

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Aer

osol

Lig

ht E

xtin

ctio

n (M

m-1

)


C-2

1

Tab

le C

-13.

Vis

ibili

ty D

ata

for

Dol

ly S

ods

IMP

RO

VE

Mon

itor

(D

eciv

iew

s).

DE

CIV

IEW

S19

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s6

1820

1818

1915

5756

5291

mea

n30

.87

30.3

630

.09

30.6

428

.36

29.4

429

.75

29.8

429

.59

29.1

929

.77

σ3.

362.

662.

983.

333.

493.

013.

823.

083.

123.

353.

12n

pts

ousi

de o

f 1 σ

24

77

88

717

2023

32n

pts

ousi

de o

f 2 σ

01

11

01

02

22

3av

g ne

gl o

utsi

de p

ts30

.87

29.9

729

.76

30.2

028

.36

29.0

429

.75

29.5

729

.30

28.9

129

.52

n pt

s ou

side

of 3

σ0

00

00

00

00

00

avg

negl

out

side

pts

30.8

730

.36

30.0

930

.64

28.3

629

.44

29.7

529

.84

29.5

929

.19

29.7

7n

pts

ousi

de o

f 4 σ

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts30

.87

30.3

630

.09

30.6

428

.36

29.4

429

.75

29.8

429

.59

29.1

929

.77

n pt

s ou

side

of 5

σ0

00

00

00

00

00

avg

negl

out

side

pts

30.8

730

.36

30.0

930

.64

28.3

629

.44

29.7

529

.84

29.5

929

.19

29.7

7%

of p

oint

s ou

tsid

e 2

σ0

65

60

50

44

43

% c

hang

e in

avg

neg

l. ot

lrs0.

0-1

.3-1

.1-1

.40.

0-1

.40.

0-0

.9-1

.0-1

.0-0

.8B

est

Day

s#

pts

618

2018

1819

1557

5652

91m

ean

11.3

315

.26

11.5

213

.09

14.3

114

.59

12.6

612

.93

14.0

413

.82

13.1

8σ

3.34

2.42

2.55

3.11

2.24

2.07

2.33

2.80

2.54

2.19

2.60

n pt

s ou

side

of 1

σ2

28

57

44

2114

1326

n pt

s ou

side

of 2

σ0

11

10

11

33

34

avg

negl

out

side

pts

11.3

315

.70

11.8

113

.47

14.3

114

.91

13.0

013

.29

14.4

114

.13

13.4

8n

pts

ousi

de o

f 3 σ

01

00

00

00

00

0av

g ne

gl o

utsi

de p

ts11

.33

15.7

011

.52

13.0

914

.31

14.5

912

.66

12.9

314

.04

13.8

213

.18

n pt

s ou

side

of 4

σ0

00

00

00

00

00

avg

negl

out

side

pts

11.3

315

.26

11.5

213

.09

14.3

114

.59

12.6

612

.93

14.0

413

.82

13.1

8n

pts

ousi

de o

f 5 σ

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts11

.33

15.2

611

.52

13.0

914

.31

14.5

912

.66

12.9

314

.04

13.8

213

.18

% o

f poi

nts

outs

ide

2 σ

06

56

05

75

56

4%

cha

nge

in a

vg n

egl.

otlrs

0.0

2.8

2.5

3.0

0.0

2.2

2.6

2.8

2.6

2.3

2.3

C-2

2

Tab

le C

-14.

Vis

ibili

ty D

ata

for

Dol

ly S

ods

IMP

RO

VE

Mon

itor

(L

ight

Ext

inct

ion)

.L

IGH

T E

XT

INC

TIO

N19

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s6

1820

1818

1915

5756

5291

mea

n21

9.79

205.

9320

1.90

216.

3217

0.69

188.

7619

9.37

197.

7719

2.88

185.

9919

6.45

σ77

.50

66.8

070

.13

83.8

563

.90

65.6

478

.50

71.2

870

.24

68.1

270

.33

n pt

s ou

side

of 1

σ2

23

38

67

1212

2326

n pt

s ou

side

of 2

σ0

22

10

10

33

26

avg

negl

out

side

pts

219.

7918

5.90

184.

4120

3.09

170.

6917

8.07

199.

3718

7.27

181.

8717

8.73

184.

03n

pts

ousi

de o

f 3 σ

00

00

00

01

10

1av

g ne

gl o

utsi

de p

ts21

9.79

205.

9320

1.90

216.

3217

0.69

188.

7619

9.37

193.

4218

8.36

185.

9919

3.73

n pt

s ou

side

of 4

σ0

00

00

00

00

00

avg

negl

out

side

pts

219.

7920

5.93

201.

9021

6.32

170.

6918

8.76

199.

3719

7.77

192.

8818

5.99

196.

45n

pts

ousi

de o

f 5 σ

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts21

9.79

205.

9320

1.90

216.

3217

0.69

188.

7619

9.37

197.

7719

2.88

185.

9919

6.45

% o

f poi

nts

outs

ide

2 σ

011

106

05

05

54

7%

cha

nge

in a

vg n

egl.

otlrs

0.0

-9.7

-8.7

-6.1

0.0

-5.7

0.0

-5.3

-5.7

-3.9

-6.3

Bes

t D

ays

# pt

s6

1820

1818

1915

5756

5291

mea

n22

.42

37.1

322

.56

28.6

032

.78

33.8

426

.33

27.7

731

.92

30.7

028

.53

σ9.

589.

357.

6310

.64

8.69

8.08

7.73

9.56

9.26

7.96

8.95

n pt

s ou

side

of 1

σ2

59

77

74

2320

1637

n pt

s ou

side

of 2

σ0

10

00

10

12

23

avg

negl

out

side

pts

22.4

238

.61

22.5

628

.60

32.7

834

.92

26.3

328

.12

32.7

231

.39

29.1

9n

pts

ousi

de o

f 3 σ

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts22

.42

37.1

322

.56

28.6

032

.78

33.8

426

.33

27.7

731

.92

30.7

028

.53

n pt

s ou

side

of 4

σ0

00

00

00

00

00

avg

negl

out

side

pts

22.4

237

.13

22.5

628

.60

32.7

833

.84

26.3

327

.77

31.9

230

.70

28.5

3n

pts

ousi

de o

f 5 σ

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts22

.42

37.1

322

.56

28.6

032

.78

33.8

426

.33

27.7

731

.92

30.7

028

.53

% o

f poi

nts

outs

ide

2 σ

06

00

05

02

44

3%

cha

nge

in a

vg n

egl.

otlrs

0.0

4.0

0.0

0.0

0.0

3.2

0.0

1.3

2.5

2.3

2.3

C-23

Figure C-15. Effect of Outliers at Great Sand Dunes IMPROVE Monitor for 2σ range(Deciviews).

Figure C-16. Effect of Outliers at Great Sand Dunes IMPROVE Monitor for 2σ range (LightExtinction).

0

2

4

6

8

10

12

14

16

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Dec

ivie

ws


0

5

10

15

20

25

30

35

40

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Aer

osol

Lig

ht E

xtin

ctio

n (M

m-1

)


C-2

4

Tab

le C

-15.

Vis

ibili

ty D

ata

for

Gre

at S

and

Dun

es IM

PR

OV

E M

onit

or (

Dec

ivie

ws)

.D

EC

IVIE

WS

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1994

-199

619

95-1

997

1996

-199

819

94-1

998

Wo

rst

Day

s#

pts

1817

1919

1820

2020

2020

6060

6010

0m

ean

13.0

713

.39

11.8

411

.14

11.7

313

.55

11.3

511

.93

11.8

312

.44

12.2

811

.71

12.1

112

.25

σ1.

151.

661.

160.

621.

404.

571.

141.

161.

681.

472.

911.

351.

412.

44n

pts

ousi

de o

f 1 σ

63

46

31

48

36

317

168

n pt

s ou

side

of 2

σ1

11

11

11

01

11

23

1av

g ne

gl o

utsi

de p

ts12

.91

13.1

111

.69

11.0

611

.51

12.5

911

.20

11.9

311

.56

12.2

711

.95

11.5

611

.90

12.0

5n

pts

ousi

de o

f 3 σ

00

00

01

00

10

11

11

avg

negl

out

side

pts

13.0

713

.39

11.8

411

.14

11.7

312

.59

11.3

511

.93

11.5

612

.44

11.9

511

.62

12.0

212

.05

n pt

s ou

side

of 4

σ0

00

00

00

00

01

00

1av

g ne

gl o

utsi

de p

ts13

.07

13.3

911

.84

11.1

411

.73

13.5

511

.35

11.9

311

.83

12.4

411

.95

11.7

112

.11

12.0

5n

pts

ousi

de o

f 5 σ

00

00

00

00

00

10

01

avg

negl

out

side

pts

13.0

713

.39

11.8

411

.14

11.7

313

.55

11.3

511

.93

11.8

312

.44

11.9

511

.71

12.1

112

.05

% o

f poi

nts

outs

ide

2 σ

66

55

65

50

55

23

51

% c

hang

e in

avg

neg

l. ot

lrs-1

.2-2

.1-1

.3-0

.7-1

.9-7

.1-1

.40.

0-2

.3-1

.4-2

.7-1

.2-1

.7-1

.6B

est

Day

s#

pts

1817

1919

1820

2020

2020

6060

6010

0m

ean

5.79

6.62

6.64

6.10

5.68

5.09

4.36

4.32

5.10

6.00

4.54

4.54

4.97

4.81

σ1.

120.

811.

490.

890.

920.

870.

700.

650.

821.

260.

750.

720.

950.

84n

pts

ousi

de o

f 1 σ

65

25

33

77

63

2120

2030

n pt

s ou

side

of 2

σ1

12

12

11

11

13

33

5av

g ne

gl o

utsi

de p

ts5.

936.

757.

086.

225.

955.

244.

454.

395.

226.

184.

644.

635.

084.

92n

pts

ousi

de o

f 3 σ

00

00

01

00

00

00

00

avg

negl

out

side

pts

5.79

6.62

6.64

6.10

5.68

5.24

4.36

4.32

5.10

6.00

4.54

4.54

4.97

4.81

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts5.

796.

626.

646.

105.

685.

094.

364.

325.

106.

004.

544.

544.

974.

81n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

5.79

6.62

6.64

6.10

5.68

5.09

4.36

4.32

5.10

6.00

4.54

4.54

4.97

4.81

% o

f poi

nts

outs

ide

2 σ

66

115

115

55

55

55

55

% c

hang

e in

avg

neg

l. ot

lrs2.

62.

06.

71.

94.

72.

82.

11.

62.

23.

02.

21.

92.

22.

3

C-2

5

Tab

le C

-16.

Vis

ibili

ty D

ata

for

Gre

at S

and

Dun

es IM

PR

OV

E M

onit

or (

Lig

ht E

xtin

ctio

n).

LIG

HT

EX

TIN

CT

ION

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1994

-199

619

95-1

997

1996

-199

819

94-1

998

Wo

rst

Day

s#

pts

1817

1919

1820

2020

2020

6060

6010

0m

ean

27.2

028

.69

22.9

020

.52

22.6

435

.92

21.3

223

.19

23.1

025

.09

26.8

222

.55

23.9

025

.79

σ4.

477.

154.

051.

945.

1146

.18

3.81

3.92

6.34

5.61

27.1

94.

825.

2621

.34

n pt

s ou

side

of 1

σ5

14

63

14

72

41

1013

1n

pts

ousi

de o

f 2 σ

11

11

11

11

12

12

31

avg

negl

out

side

pts

26.5

427

.35

22.3

220

.26

21.7

825

.68

20.7

722

.76

22.0

023

.71

23.3

721

.98

23.0

723

.73

n pt

s ou

side

of 3

σ0

00

00

10

01

01

11

1av

g ne

gl o

utsi

de p

ts27

.20

28.6

922

.90

20.5

222

.64

25.6

821

.32

23.1

922

.00

25.0

923

.37

22.1

823

.56

23.7

3n

pts

ousi

de o

f 4 σ

00

00

01

00

00

11

01

avg

negl

out

side

pts

27.2

028

.69

22.9

020

.52

22.6

425

.68

21.3

223

.19

23.1

025

.09

23.3

722

.18

23.9

023

.73

n pt

s ou

side

of 5

σ0

00

00

00

00

01

00

1av

g ne

gl o

utsi

de p

ts27

.20

28.6

922

.90

20.5

222

.64

35.9

221

.32

23.1

923

.10

25.0

923

.37

22.5

523

.90

23.7

3%

of p

oint

s ou

tsid

e 2

σ6

65

56

55

55

102

35

1%

cha

nge

in a

vg n

egl.

otlrs

-2.4

-4.7

-2.5

-1.3

-3.8

-28.

5-2

.6-1

.9-4

.8-5

.5-1

2.9

-2.5

-3.5

-8.0

Bes

t D

ays

# pt

s18

1719

1918

2020

2020

2060

6060

100

mea

n7.

949.

449.

618.

487.

726.

705.

505.

436.

718.

355.

795.

796.

516.

23σ

1.94

1.52

2.56

1.59

1.54

1.36

1.06

0.99

1.32

2.12

1.15

1.11

1.53

1.32

n pt

s ou

side

of 1

σ6

52

54

48

76

421

2221

30n

pts

ousi

de o

f 2 σ

11

21

21

10

11

33

25

avg

negl

out

side

pts

8.18

9.67

10.3

58.

678.

156.

915.

635.

436.

898.

645.

945.

926.

636.

39n

pts

ousi

de o

f 3 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

7.94

9.44

9.61

8.48

7.72

6.70

5.50

5.43

6.71

8.35

5.79

5.79

6.51

6.23

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts7.

949.

449.

618.

487.

726.

705.

505.

436.

718.

355.

795.

796.

516.

23n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

7.94

9.44

9.61

8.48

7.72

6.70

5.50

5.43

6.71

8.35

5.79

5.79

6.51

6.23

% o

f poi

nts

outs

ide

2 σ

66

115

115

50

55

55

35

% c

hang

e in

avg

neg

l. ot

lrs3.

02.

47.

72.

35.

63.

22.

40.

02.

63.

42.

52.

21.

82.

6

C-26

Figure C-17. Effect of Outliers at Great Smoky Mountains IMPROVE Monitor for 2σ range(Deciviews).

Figure C-18. Effect of Outliers at Great Smoky Mountains IMPROVE Monitor for 2σ range(Light Extinction).

0

5

10

15

20

25

30

35

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Dec

ivie

ws


0

50

100

150

200

250

300

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Aer

osol

Lig

ht E

xtin

ctio

n (M

m-1

)


C-2

7

Tab

le C

-17.

Vis

ibili

ty D

ata

for

Gre

at S

mok

y M

ount

ains

IMP

RO

VE

Mon

itor

(D

eciv

iew

s).

DE

CIV

IEW

S19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s13

1714

1918

1820

1919

1557

5854

92m

ean

30.3

531

.79

29.2

029

.92

29.1

029

.78

29.8

230

.39

30.8

232

.32

30.0

030

.37

31.1

430

.63

σ2.

031.

933.

682.

071.

942.

282.

652.

002.

291.

412.

312.

291.

992.

21n

pts

ousi

de o

f 1 σ

55

45

26

77

76

1921

1935

n pt

s ou

side

of 2

σ0

00

11

10

11

02

11

2av

g ne

gl o

utsi

de p

ts30

.35

31.7

929

.20

29.6

428

.75

29.4

429

.82

30.1

630

.52

32.3

229

.81

30.2

731

.04

30.5

1n

pts

ousi

de o

f 3 σ

00

00

10

00

00

00

00

avg

negl

out

side

pts

30.3

531

.79

29.2

029

.92

28.7

529

.78

29.8

230

.39

30.8

232

.32

30.0

030

.37

31.1

430

.63

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts30

.35

31.7

929

.20

29.9

229

.10

29.7

829

.82

30.3

930

.82

32.3

230

.00

30.3

731

.14

30.6

3n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

30.3

531

.79

29.2

029

.92

29.1

029

.78

29.8

230

.39

30.8

232

.32

30.0

030

.37

31.1

430

.63

% o

f poi

nts

outs

ide

2 σ

00

05

66

05

50

42

22

% c

hang

e in

avg

neg

l. ot

lrs0.

00.

00.

0-1

.0-1

.2-1

.10.

0-0

.8-1

.00.

0-0

.6-0

.3-0

.3-0

.4B

est

Day

s#

pts

1317

1419

1818

2019

1915

5758

5492

mea

n15

.51

15.4

413

.06

13.3

714

.30

13.6

513

.36

15.1

714

.70

13.8

713

.95

14.2

914

.63

14.1

2σ

2.24

2.06

2.44

2.33

2.66

1.95

2.71

2.10

1.42

2.59

2.28

2.15

2.03

2.18

n pt

s ou

side

of 1

σ1

84

64

82

33

113

811

15n

pts

ousi

de o

f 2 σ

10

11

11

22

11

33

24

avg

negl

out

side

pts

16.0

115

.44

13.4

613

.75

14.7

813

.92

14.1

315

.74

14.8

914

.42

14.3

214

.66

14.8

914

.44

n pt

s ou

side

of 3

σ0

00

01

00

00

01

21

3av

g ne

gl o

utsi

de p

ts15

.51

15.4

413

.06

13.3

714

.78

13.6

513

.36

15.1

714

.70

13.8

714

.10

14.5

714

.79

14.3

8n

pts

ousi

de o

f 4 σ

00

00

00

00

00

01

10

avg

negl

out

side

pts

15.5

115

.44

13.0

613

.37

14.3

013

.65

13.3

615

.17

14.7

013

.87

13.9

514

.44

14.7

914

.12

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts15

.51

15.4

413

.06

13.3

714

.30

13.6

513

.36

15.1

714

.70

13.8

713

.95

14.2

914

.63

14.1

2%

of p

oint

s ou

tsid

e 2

σ8

07

56

610

115

75

54

4%

cha

nge

in a

vg n

egl.

otlrs

3.2

0.0

3.0

2.8

3.4

2.0

5.8

3.7

1.3

4.0

2.7

2.6

1.7

2.3

C-2

8

Tab

le C

-18.

Vis

ibili

ty D

ata

for

Gre

at S

mok

y M

ount

ains

IMP

RO

VE

Mon

itor

(L

ight

Ext

inct

ion)

.L

IGH

T E

XT

INC

TIO

N19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s13

1714

1918

1820

1919

1557

5854

92m

ean

202.

1423

4.64

188.

1019

3.69

177.

3419

1.60

194.

4820

2.90

213.

8824

5.60

196.

4120

4.13

219.

4920

9.27

σ45

.95

50.1

278

.31

46.9

643

.52

50.1

859

.37

43.3

055

.92

35.5

150

.82

52.5

247

.07

50.8

2n

pts

ousi

de o

f 1 σ

24

34

16

47

46

1613

1932

n pt

s ou

side

of 2

σ1

20

11

11

11

05

21

3av

g ne

gl o

utsi

de p

ts19

3.86

220.

5418

8.10

186.

4416

8.52

183.

0218

8.14

197.

2220

5.29

245.

6018

5.24

199.

2121

6.68

204.

85n

pts

ousi

de o

f 3 σ

00

00

10

00

00

01

11

avg

negl

out

side

pts

202.

1423

4.64

188.

1019

3.69

168.

5219

1.60

194.

4820

2.90

213.

8824

5.60

196.

4120

1.24

216.

6820

7.52

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts20

2.14

234.

6418

8.10

193.

6917

7.34

191.

6019

4.48

202.

9021

3.88

245.

6019

6.41

204.

1321

9.49

209.

27n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

202.

1423

4.64

188.

1019

3.69

177.

3419

1.60

194.

4820

2.90

213.

8824

5.60

196.

4120

4.13

219.

4920

9.27

% o

f poi

nts

outs

ide

2 σ

812

05

66

55

50

93

23

% c

hang

e in

avg

neg

l. ot

lrs-4

.1-6

.00.

0-3

.7-5

.0-4

.5-3

.3-2

.8-4

.00.

0-5

.7-2

.4-1

.3-2

.1B

est

Day

s#

pts

1317

1419

1818

2019

1915

5758

5492

mea

n38

.15

37.7

327

.87

28.9

733

.04

29.8

429

.18

36.4

833

.89

31.1

231

.27

32.5

833

.99

31.8

9σ

9.21

9.36

8.12

8.05

9.52

7.26

8.44

8.64

5.78

8.83

7.97

7.57

7.69

7.73

n pt

s ou

side

of 1

σ3

84

74

83

54

416

1215

25n

pts

ousi

de o

f 2 σ

10

01

11

21

11

33

24

avg

negl

out

side

pts

40.0

137

.73

27.8

730

.07

34.4

930

.74

31.4

237

.57

34.6

032

.74

32.4

033

.72

34.8

132

.87

n pt

s ou

side

of 3

σ0

00

00

00

00

00

11

2av

g ne

gl o

utsi

de p

ts38

.15

37.7

327

.87

28.9

733

.04

29.8

429

.18

36.4

833

.89

31.1

231

.27

33.0

234

.47

32.4

2n

pts

ousi

de o

f 4 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

38.1

537

.73

27.8

728

.97

33.0

429

.84

29.1

836

.48

33.8

931

.12

31.2

732

.58

33.9

931

.89

n pt

s ou

side

of 5

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts38

.15

37.7

327

.87

28.9

733

.04

29.8

429

.18

36.4

833

.89

31.1

231

.27

32.5

833

.99

31.8

9%

of p

oint

s ou

tsid

e 2

σ8

00

56

610

55

75

54

4%

cha

nge

in a

vg n

egl.

otlrs

4.9

0.0

0.0

3.8

4.4

3.0

7.7

3.0

2.1

5.2

3.6

3.5

2.4

3.1

C-29

Figure C-19. Effect of Outliers at Point Reyes IMPROVE Monitor for 2σ range (Deciviews).

Figure C-20. Effect of Outliers at Point Reyes IMPROVE Monitor for 2σ range (LightExtinction).

0

5

10

15

20

25

30

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Dec

ivie

ws


0

20

40

60

80

100

120

140

1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1994-1996

1995-1997

1996-1998

1994-1998

Year

Aer

osol

Lig

ht E

xtin

ctio

n (M

m-1

)


C-3

0

Tab

le C

-19.

Vis

ibili

ty D

ata

for

Poi

nt R

eyes

IMP

RO

VE

Mon

itor

(D

eciv

iew

s).

DE

CIV

IEW

S19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s16

1819

1620

1815

1713

1452

4745

80m

ean

25.0

021

.70

22.1

520

.93

21.5

223

.76

20.5

119

.46

20.2

718

.89

21.1

719

.92

19.4

920

.59

σ5.

022.

914.

913.

465.

084.

993.

921.

773.

102.

014.

192.

972.

293.

77n

pts

ousi

de o

f 1 σ

35

41

38

34

33

87

814

n pt

s ou

side

of 2

σ0

10

11

02

11

14

34

5av

g ne

gl o

utsi

de p

ts25

.00

21.3

322

.15

20.1

720

.80

23.7

619

.17

19.1

819

.74

18.4

720

.31

19.3

518

.94

19.9

0n

pts

ousi

de o

f 3 σ

00

01

00

00

00

01

12

avg

negl

out

side

pts

25.0

021

.70

22.1

520

.17

21.5

223

.76

20.5

119

.46

20.2

718

.89

21.1

719

.71

19.3

320

.28

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts25

.00

21.7

022

.15

20.9

321

.52

23.7

620

.51

19.4

620

.27

18.8

921

.17

19.9

219

.49

20.5

9n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

25.0

021

.70

22.1

520

.93

21.5

223

.76

20.5

119

.46

20.2

718

.89

21.1

719

.92

19.4

920

.59

% o

f poi

nts

outs

ide

2 σ

06

06

50

136

87

86

96

% c

hang

e in

avg

neg

l. ot

lrs0.

0-1

.70.

0-3

.7-3

.30.

0-6

.5-1

.4-2

.6-2

.2-4

.1-2

.9-2

.8-3

.4B

est

Day

s#

pts

1618

1916

2018

1517

1314

5247

4580

mea

n8.

909.

839.

118.

839.

548.

387.

797.

958.

249.

248.

118.

058.

458.

34σ

1.72

1.22

1.09

0.97

1.15

1.76

1.35

1.01

1.61

1.20

1.41

1.32

1.32

1.44

n pt

s ou

side

of 1

σ4

66

78

34

85

317

1418

30n

pts

ousi

de o

f 2 σ

01

10

11

00

00

22

24

avg

negl

out

side

pts

8.90

10.0

09.

248.

839.

668.

637.

797.

958.

249.

248.

258.

188.

588.

52n

pts

ousi

de o

f 3 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

8.90

9.83

9.11

8.83

9.54

8.38

7.79

7.95

8.24

9.24

8.11

8.05

8.45

8.34

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts8.

909.

839.

118.

839.

548.

387.

797.

958.

249.

248.

118.

058.

458.

34n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

8.90

9.83

9.11

8.83

9.54

8.38

7.79

7.95

8.24

9.24

8.11

8.05

8.45

8.34

% o

f poi

nts

outs

ide

2 σ

06

50

56

00

00

44

45

% c

hang

e in

avg

neg

l. ot

lrs0.

01.

71.

40.

01.

33.

00.

00.

00.

00.

01.

71.

51.

52.

1

C-3

1

Tab

le C

-20.

Vis

ibili

ty D

ata

for

Poi

nt R

eyes

IMP

RO

VE

Mon

itor

(L

ight

Ext

inct

ion)

.L

IGH

T E

XT

INC

TIO

N19

8919

9019

9119

9219

9319

9419

9519

9619

9719

9819

94-1

996

1995

-199

719

96-1

998

1994

-199

8W

ors

t D

ays

# pt

s16

1819

1620

1815

1713

1452

4745

80m

ean

128.

3481

.50

94.2

377

.38

90.4

411

1.75

74.7

661

.07

69.7

257

.47

82.0

367

.20

62.2

575

.37

σ78

.02

30.2

161

.16

46.7

572

.75

66.4

043

.62

13.7

128

.56

15.5

750

.72

30.1

819

.69

43.8

3n

pts

ousi

de o

f 1 σ

23

41

33

22

31

67

59

n pt

s ou

side

of 2

σ1

11

11

12

11

14

34

5av

g ne

gl o

utsi

de p

ts11

6.39

77.1

486

.54

66.1

378

.09

102.

8459

.17

58.7

364

.45

53.9

570

.05

60.7

557

.20

66.1

4n

pts

ousi

de o

f 3 σ

00

01

10

00

00

22

13

avg

negl

out

side

pts

128.

3481

.50

94.2

366

.13

78.0

911

1.75

74.7

661

.07

69.7

257

.47

75.2

462

.36

60.6

568

.99

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

1av

g ne

gl o

utsi

de p

ts12

8.34

81.5

094

.23

77.3

890

.44

111.

7574

.76

61.0

769

.72

57.4

782

.03

67.2

062

.25

72.9

9n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

128.

3481

.50

94.2

377

.38

90.4

411

1.75

74.7

661

.07

69.7

257

.47

82.0

367

.20

62.2

575

.37

% o

f poi

nts

outs

ide

2 σ

66

56

56

136

87

86

96

% c

hang

e in

avg

neg

l. ot

lrs-9

.3-5

.3-8

.2-1

4.5

-13.

7-8

.0-2

0.9

-3.8

-7.6

-6.1

-14.

6-9

.6-8

.1-1

2.2

Bes

t D

ays

# pt

s16

1819

1620

1815

1713

1452

4745

80m

ean

14.6

716

.91

15.0

114

.28

16.1

113

.43

11.9

712

.26

13.0

615

.35

12.7

212

.56

13.4

813

.26

σ4.

033.

202.

622.

392.

903.

772.

892.

243.

532.

883.

072.

893.

003.

18n

pts

ousi

de o

f 1 σ

46

67

87

48

53

1916

1934

n pt

s ou

side

of 2

σ0

10

00

10

00

01

00

2av

g ne

gl o

utsi

de p

ts14

.67

17.3

115

.01

14.2

816

.11

13.9

211

.97

12.2

613

.06

15.3

512

.87

12.5

613

.48

13.4

4n

pts

ousi

de o

f 3 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

14.6

716

.91

15.0

114

.28

16.1

113

.43

11.9

712

.26

13.0

615

.35

12.7

212

.56

13.4

813

.26

n pt

s ou

side

of 4

σ0

00

00

00

00

00

00

0av

g ne

gl o

utsi

de p

ts14

.67

16.9

115

.01

14.2

816

.11

13.4

311

.97

12.2

613

.06

15.3

512

.72

12.5

613

.48

13.2

6n

pts

ousi

de o

f 5 σ

00

00

00

00

00

00

00

avg

negl

out

side

pts

14.6

716

.91

15.0

114

.28

16.1

113

.43

11.9

712

.26

13.0

615

.35

12.7

212

.56

13.4

813

.26

% o

f poi

nts

outs

ide

2 σ

06

00

06

00

00

20

03

% c

hang

e in

avg

neg

l. ot

lrs0.

02.

40.

00.

00.

03.

60.

00.

00.

00.

01.

20.

00.

01.

4

INTERPOLATING RELATIVE HUMIDITY W EIGHTING FACTORS … RH.pdf · INTERPOLATING RELATIVE HUMIDITY W...

Documents

Transcript of INTERPOLATING RELATIVE HUMIDITY W EIGHTING FACTORS … RH.pdf · INTERPOLATING RELATIVE HUMIDITY W...