Trends in the Wet and Dry Deposition of Nitrogen and Sulfur Species Christopher Lehmann.
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Transcript of Trends in the Wet and Dry Deposition of Nitrogen and Sulfur Species Christopher Lehmann.
Trends in the Wet and Dry Deposition of Nitrogen and
Sulfur Species
Christopher Lehmann
Atmospheric Deposition
EMISSIONS
REMOVAL
Precipitation volume/time
WET DEPOSITIONPRECIPITATION
DRY DEPOSITIONAEROSOL PARTICLES
& GASES
Deposition velocity
ATMOSPHERIC TRANSPORT & TRANSFORMATION
REACTIONS
ADVERSEENVIRONMENTAL
EFFECTS
Atmospheric Emissions
0
5
10
15
20
25
30
1970 1975 1980 1985 1990 1995 2000 2005
Em
issi
on
s, T
erag
ram
s
Ammonia Nitrogen Oxides Sulfur Dioxide
2010
8.1 Tg
1990 Clean Air Act Amendments9.1 Tg reduction (1980-2000)
Source: U.S. EPA
Atmospheric Emissions
0
5
10
15
20
25
30
1970 1975 1980 1985 1990 1995 2000 2005
Em
issi
on
s, T
erag
ram
s
Ammonia Nitrogen Oxides Sulfur Dioxide
1990 Clean Air Act Amendmentspower plant and mobile source emissions reduced
Source: U.S. EPA
Atmospheric Emissions
0
5
10
15
20
25
30
1970 1975 1980 1985 1990 1995 2000 2005
Em
issi
on
s, T
erag
ram
s
Ammonia Nitrogen Oxides Sulfur Dioxide
Ammonia Increases?
Source: U.S. EPA
…or not?
National Trends Network (NTN)
Source: NADP
Sulfate Ion Concentrations1985-2004
1985 19861984
Source: NADP
2004 20052003
Sulfate Ion Concentrations1985-2004
Source: NADP
Sulfate Trend in Precipitation1985-2004
INCREASING
Trend
DECREASING
TrendNumber of
SitesNumber
SignificantNumber of Sites Number
Significant
5 0 154 141
Seasonal Kendall Trend Test, α = 90%Sen’s Median Estimator of Trend
Sulfate Trend in Precipitation1985-2004
INCREASING
Trend
DECREASING
TrendNumber of
SitesNumber
SignificantNumber of Sites Number
Significant
5 0 154 141
Trends Emissions Concentration
-45% -46%
Nitrate Ion Concentrations1985-2004
1985 19861984
Source: NADP
Nitrate Ion Concentrations1985-2004
2004 20052003
Source: NADP
INCREASING
Trend
DECREASING
TrendNumber of
SitesNumber
SignificantNumber of Sites Number
Significant
71 36 88 45
Nitrate Trend in Precipitation1985-2004
Seasonal Kendall Trend Test, α = 90%Sen’s Median Estimator of Trend
INCREASING
Trend
DECREASING
TrendNumber of
SitesNumber
SignificantNumber of Sites Number
Significant
71 36 88 45
Nitrate Trend in Precipitation1985-2004
Trends Emissions Concentration
-17% -3%
Ammonium Ion Concentrations1985-2004
1985 19861984
Source: NADP
2004 20052003
Ammonium Ion Concentrations1985-2004
Source: NADP
Ammonium Trend in Precipitation1985-2004
INCREASING
Trend
DECREASING
TrendNumber of
SitesNumber
SignificantNumber of Sites Number
Significant
142 101 17 3
Seasonal Kendall Trend Test, α = 90%Sen’s Median Estimator of Trend
Ammonium Trend in Precipitation1985-2004
INCREASING
Trend
DECREASING
TrendNumber of
SitesNumber
SignificantNumber of Sites Number
Significant
142 101 17 3
Trends Emissions Concentration
+24% +29%
Atmospheric Deposition
EMISSIONS
REMOVAL
Precipitation volume/time
WET DEPOSITIONPRECIPITATION
DRY DEPOSITIONAEROSOL PARTICLES
& GASES
Deposition velocity
ATMOSPHERIC TRANSPORT & TRANSFORMATION
REACTIONS
ADVERSEENVIRONMENTAL
EFFECTS
CASTNET Filter Pack
Images provided by Clean Air Status and Trends Network (U.S. EPA)
Clean Air Status & TrendsNetwork (CASTNET)
• Weekly 3-stage filter pack samples– Teflon filter: particulate sulfate and nitrate– Nylon filter: nitric acid, sulfur dioxide– Impregnated cellulose: sulfur dioxide
CASTNET
Source: www.epa.gov/castnet
NTN NV05Great Basin National Park
CASTNET CTH110Connecticut Hill, NY
Precipitation Sulfate Concentrations, 2003-2005
(NADP)
Particulate SulfateConcentrations, 2003-2005
(CASTNET)
Particulate Sulfate Concentration Trend
Precipitation Sulfate Concentration Trend
NADP/NTNCASTNET
Precipitation Nitrate Concentrations, 2003-2005
(NADP)
Particulate NitrateConcentrations, 2003-2005
(CASTNET)???
???
Precipitation Ammonium Concentrations, 2003-2005
(NADP)
Particulate AmmoniumConcentrations, 2003-2005
(CASTNET)
???
Particulate AmmoniumConcentration Trend
Precipitation AmmoniumConcentration Trend
NADP/NTNCASTNET
CMU-model Ammonia-N Emissions 2002 (includes soil emissions)
2000 - 1990 Emissions Differences
???
??? Ammonia Emissions vs.
Ammonium Trends1985 – 2004 Ammonium Trend
Why do trends in ammonia emissions and ammonium
deposition differ?
Sulfate, Ammonium & Nitrate Reactions
Transport Distance
NH4+ HSO4
-+ ⇌ NH4+ NH4
+ SO4=
Seinfeld and Pandis, 1998
NH4+ +
Ammonium Sulfate
Sulfate, Ammonium & Nitrate Reactions
Transport Distance
NH4+ HSO4
-+ ⇌ NH4+ NH4
+ SO4=
NH3,g HNO3,g+ ⇌ NH4 NO3
Seinfeld and Pandis, 1998
NH4+ +
Ammonium Sulfate
Ammonium Nitrate
Sulfate, Ammonium & Nitrate Reactions
Transport Distance
NH4+ HSO4
-+ ⇌ NH4+ NH4
+ SO4=
NH3,g HNO3,g+ ⇌ NH4 NO3
NH3,g
Seinfeld and Pandis, 1998
NH4+ +
Ammonium Sulfate
Ammonium Nitrate
Ammonia Gas
Ammonium vs. Sulfate TrendsBondville, IL
Particulate Concentrations
Precipitation Concentrations
Ammonia vs. Ammonium ConcentrationsBondville, IL
LOESS of Raw Data180-day window
0
20
40
60
80
100
1-Nov-04 6-Nov-04 11-Nov-04 16-Nov-04 21-Nov-04 26-Nov-04 1-Dec-04 6-Dec-04 11-Dec-04
Am
moniu
m c
once
ntr
atio
n in
Pre
cipitat
ion,u
eq/L
0
5
10
15
20
Am
monia
Conce
ntr
atio
n in
Gas
,ppb
Ammonium in Precipitation Ammonia in Gas
Ammonia Gas vs. Precipitation AmmoniumBondville, IL
Conclusion
There is a need for a network of ammonia gas monitoring sites in the U.S. (nitric acid too….)– Compare with precipitation ammonium
measurements from the NADP/NTN, particulate ammonium from CASTNET
– Validate ammonia emissions inventories– Improves evaluation of nitrogen dry deposition
with measurements not currently included in existing networks.
How to Monitor Ammonia Gas
Source: www.ogawausa.com
Source: Minutes, NADP Joint Subcommittee, Fall 2005 (attachments)
Acknowledgements
The NADP receives support from the U.S. Geological Survey; Environmental Protection Agency; National Park Service; National Oceanic and Atmospheric Administration; U.S. Department of Agriculture-Forest Service; U.S. Fish & Wildlife Service; Bureau of Land Management; Tennessee Valley Authority; and U.S. Department of Agriculture - Cooperative State Research, Education, and Extension Service via cooperative agreement. Additional support is provided by other federal, state, local, and tribal agencies, State Agricultural Experiment Stations, universities, and nongovernmental organizations. Any findings or conclusions in this presentatoin do not reflect the views of the U.S. Department of Agriculture or other NADP sponsors.
S. Larson, V. Bowersox, T. Bond, D. Wuebbles
Colleagues at:
National Atmospheric Deposition Program
Illinois State Water Survey