Presentation Slides for Chapter 15 of Fundamentals of Atmospheric Modeling 2 nd Edition
Presentation Slides for Chapter 11, Part 1 of Fundamentals of Atmospheric Modeling 2 nd Edition
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Transcript of Presentation Slides for Chapter 11, Part 1 of Fundamentals of Atmospheric Modeling 2 nd Edition
Presentation Slides for
Chapter 11, Part 1of
Fundamentals of Atmospheric Modeling 2nd Edition
Mark Z. JacobsonDepartment of Civil & Environmental Engineering
Stanford UniversityStanford, CA [email protected]
March 21, 2005
Types of GasesInorganic gases
Contain O, N, S, Cl, Br, and maybe H or C, but not both
Nitric oxide --
Organic gasesContain both H and C, but may also contain other atoms
Carbon dioxide --
Formaldehyde --
Acetone --
Peroxyacetylnitrate --
N O O C O
H C
O
H
H C
H
C
H
O
C
H
H
H
C C
O
O
H
H
H
O
N
O
O
HydrocarbonsOrganic gases that contain only hydrogen and carbon
Propane --
Alkanes - Carbons bonded by a single bond
Cyclobutane --
Ethene (ethylene) --
Cycloalkanes - A ring of alkanes
Alkenes - Carbons bonded by a double bond
H C
H
C
H
H
C
H
H
H
H
H2
C
H2
C CH2
CH2
C C
H
H
H
H
Hydrocarbons
Toluene --
Aromatics - Carbons that form a benzene ring
Isoprene --
Terpenes - Biogenic hydrocarbons
CH3
H
C C
H2
CCH
2
CH3
DefinitionsNon-methane hydrocarbons (NMHC)
Hydrocarbons, except for methane
Oxygenated hydrocarbonsHydrocarbons with oxygenated functional groups, such as aldehydes, ketones, alcohols, acids, and nitrates, added to them
Reactive organic gas (ROG)The sum of oxygenated and NMHC
Total organic gas (TOG)The sum of ROG and methane
Photostationary State Relationship(11.1)
(11.2)
(11.3)
NO + O3
NO2
+ O2
NO2
+ h ν + NO O λ < 420 nm
O + O2
+ M O3
+ M
d NO2[ ]dt
=k1 NO[ ] O3[ ]−J NO2[ ]
O3[ ]=J NO2[ ]k1 NO[ ]
Time rate of change of nitrogen dioxide (11.4)
Steady state --> photostationary state relationship (11.5)
Photostationary State RelationshipExample 11.1:Estimate ozone mixing ratio when
pa = 1013 hPa T = 298 KNO = 5 pptv NO2 = 10 pptvk1 = 1.8x10-14 cm3 molec.-1 s-1 J = 0.01 s-1
Solution:[O3] = 1.1x1012 molec. cm-3
Nd = 2.46 x 1019 molec. cm-3
O3 = 44.7 ppbv
Other Reactions Affecting OzonePhotodissociation of ozone (11.6)
(11.7)
Conversion of excited to ground-state atomic oxygen (11.8)
O3
+ h νO
2 + (O
1
D ) λ < 310 nm
O3
+ h ν O2
+ O λ > 310 nm
O(
1
D ) O
M
Hydroxyl Radical SourcesMajor (11.9)
Minor (11.10-13)
O(1
D ) + H2
O 2OH
HONO + h ν + OH NO λ < 400 nm
HNO3
+ h ν + OH NO2
λ < 335 nm
H2
O2
+ h ν 2OH λ < 355 nm
HO2
NO2
+ h ν
HO2
+ NO2
+ OH NO3
λ < 330 nm
λ < 330 nm
Scavenging by Hydroxyl Radical(11.14-17)
OH + O3
HO2
+ O2
OH + H2
H2
O + H
OH + HO2
H2
O + O2
OH + H2
O2
HO2
+ H2
O
Scavenging by Hydroxyl Radical(11.19-23)
M
OH + NO2
HNO3
OH + SO2
HSO3
M
OH + CO H + CO2
OH + CH4
H2
O + CH3
Hydroperoxy Radical Production
(11.27)
(11.28)
M
H + O2
HO2
HO2
NO2
HO2
+ NO2
M
Hydroperoxy Radical Loss
Hyrdoxyl radical reactions in presence of NO (11.29)
(11.30)
(11.31)
(NO > 10 pptv)
(NO 3-10 pptv)
(NO < 3 pptv)
M
H O2
+ NO OH + NO2
HO2
+ NO2
HO2
NO2
HO2 +
O3
OH + 2O2
HO2
+ HO2
H2
O2
+ O2
Nighttime Nitrogen Chemistry
Production of nitrate radical (11.32)
Dinitrogen pentoxide formation / decomposition (11.33)
NO2
+ O3
NO3
+ O2
M
NO2
+ NO3
N2
O5
Nighttime Nitrogen Chemistry
Dinitrogen pentoxide reaction, photolysis (11.34)
Nitrate radical photolysis (lifetime of minutes) (11.35)
(11.36)
N2
O5
+ H2
O(aq) 2HNO3
(aq)
N2
O5
+ h ν NO2
+ NO3
λ < 385 nm
NO3
+ h ν
NO2
+ O
+ NO O2
410 <nm λ < 670 nm
590 < nm λ < 630 nm
Ozone From Carbon Monoxide
(11.37-41)CO + OH CO2
+ H
M
H + O2
HO2
NO + HO2
NO2
+ OH
NO2
+ h ν + NO O λ < 420 nm
O + O2
+ M O3
+ M
Ozone Formation From Methane(11.42)
(11.43)
CH4
+ OH CH3
+ H2
O
+ O2
, M
C
H
H
H
Methyl
radical
C
H
H
H
O
O
Methylperoxy
radical
H
C O
H
H
Methoxy
radical
O2
NO2
+ NO
+ HO2
H C
H
O
H
O H
Methyl
hydroperoxide
H C
O
H
Formaldehyde
+ O2
HO2
(11.40)
(11.41)
NO2
+ h ν + NO O λ < 420 nm
O + O2
+ M O3
+ M
Methyl Hydroperoxide Decomposition
(11.44)
H C
O
H
Formaldehyde
+ O2
HO2
H
C O
HOH
Methoxy
radical
H C
H
O
H
O H
+ h ν
C
H
H
H
O
O
Methylperoxy
radical
Methyl
hydroperoxide
λ < 360 nm
H
+ OH
H2
O
Ethane Oxidation
Methylperoxy radical production and loss (11.45)
Ethane
H C
H
C
H
H
H
H C
H
C
H
H
H
Ethyl radical
H
H C
H
C
H
O
H
H
O
Ethylperoxy radical
+ O2
, M
+ OH
H2
O
Ethane Oxidation(11.46)
H C
H
C
H
O
H
H
O
Ethylperoxy radical
H C
H
C
H
H
H
Ethoxy radical
O
NO2
+ NO
Acetaldehyde
H C
H
C
H
O
H
+ O2
HO2
+ NO2
M
H C
H
C
H
H
O
H
Ethylperoxynitric acid
O
N
O
O
Propane OxidationMethylperoxy radical production and loss (11.47)
+ O2
, M
H C
H
C
H
H
C
H
H
HH C
H
C
H
H
C
H
H
Propane n -Propyl radical
H H
H C
H
C
H
H
C
H
H
O
H
n -Propylperoxy radical
O
+ OH
H2
O
NO2
+ NO
H C
H
C
H
H
H
n -Propoxy radical
C
H
H
O H C
H
C
H
O
C
H
H
H
Acetone
+ O2
HO2
Formaldehyde/Acetaldehyde PhotolysisFormaldehyde (11.48)
Acetaldehyde (11.49)
Eormyl radical (11.50)
H C
O
H
Formaldehyde
+ h ν
+ H
Formyl
radical
+ CO H2
λ < 334 nm
λ < 370 nm
C
HO
+ h ν
C
H
H
H
CH C
H
C
H
Acetaldehyde Methyl radical Formyl radical
+
O
H
O
H
λ < 325 nm
Formyl
radical
C
O
H
CO
+ O2
HO2
Formaldehyde/Acetaldehyde ReactionFormaldehyde (11.51)
Acetaldehyde (11.52)
CH C
Formaldehyde Formyl radical
O
H
O
H
+ OH
H2
O
C C
O
H
H
H
H
Acetaldehyde Acetyl radical
C C
OH
H
H
Peroxyacetyl
radical
C C
O
O
H
H
H
O
+ OH
H2
O
+ O2
, M
Formaldehyde/Acetaldehyde Reaction
PAN formation (11.53)
Peroxyacetyl
radical
C C
O
O
H
H
H
O
Acetyloxy radical
C C
O
O
H
H
H
Peroxyacetyl nitrate
C C
O
O
H
H
H
O
N
O
O
NO2
+ NO
+ NO2
, M
Acetone Photolysis
(11.55)
H C
H
C
H
O
C
H
H
H
Acetone
+ h νC
H
H
H
Methyl radical
+
Acetyl radical
C C
OH
H
H
Sulfur PhotochemistryBiogenic sulfur
H2S -- hydrogen sulfide
CH3SH -- methyl sulfide
CH3SCH3 -- dimethyl sulfide (DMS)
CH3SSCH3 -- methyl disulfide
Volcanic sulfur
CS2 -- carbon disulfide
OCS -- carbonyl sulfide
SO2 -- sulfur dioxide
H2S -- hydrogen sulfide
Sulfur Photochemistry
Sulfuric acid formation from sulfur dioxide (11.74)
S
OO
O
S
HO O
O
S
O O
+ OH, M+ H
2O
Sulfur
dioxide
Bisulfite Sulfur
trioxide
Sulfuric
acid
S
O
OH
O OH
+ O2
HO2
DMS Abstraction Pathway
Sulfur dioxide production from dimethyl sulfide (DMS) (11.56)
+ O2
H C
H
S
H
C
H
H
H H C
H
S
H
C
H
H
H C
H
S
H
C
H
H
O
O
Dimethyl sulfide (DMS) DMS radical DMS peroxy radical
+ OH
H2
O
H C
H
S
H
C
H
H
O H C
H
S
H
+
H C
O
H
DMS oxy radical Methanethiolate
radical
Formaldehyde
M
NO2
+ NO
DMS Abstraction Pathway
Methanethiolate radical reaction (11.57)
H C
H
S
H
H C
H
S
H
O
O
Methanethiolate
radical
Excited methanethiolate
peroxy radical
*
H C
H
S
H
O
O
Methanethiolate oxy
radical
Methanethiolate
peroxy radical
M
H C
H
S
H
O
+ O2
, M
NO2
+ NO
DMS Abstraction Pathway
Methanethiolate oxy radical reaction (11.58)
H C
H
H
Methyl
radical
H C
H
S
H
O
+
H C
H
S
H
O
O
S O
Sulfur monoxide
Methanethiolate
peroxy radical
Methanethiolate oxy
radical
M
+ O3
O2
DMS Abstraction Pathway
Sulfur dioxide production from sulfur oxide (11.59)
Sulfur dioxide production from sulfur oxide (11.60)
S
OO
OSulfur
monoxide
S O
Sulfur
dioxide
+ O2
S
OO
H C
H
H
+H C
H
S
H
O
O
Methyl radical Sulfur dioxideMethanethiolate
peroxy radical
M
DMS Addition Pathway
Methanethiolate oxy radical reaction (11.61)
H C
H
S
H
C
H
H
H
+ OH
Dimethyl sulfide (DMS)
H C
H
S
H
C
H
H
H
OH
H C
H
H
H C
H
S
H
O
H
O
S C
O
C
H
H
H
H
H
H
+
Dimethyl sulfone (DMSO2
)
Methanesulfenic
acid
Methyl
radical
DMS-OH adduct
M
+ OH, 2O2
2 HO2
DMS Addition Pathway
Methanesulfenic acid oxidation (11.62)
Methanethiolate oxy
radical
H C
H
S
H
O
H
Methanesulfenic
acid
H C
H
S
H
O
+ OH
H2
O
DMDS Reaction
OH addition (11.63)
Photolysis (11.64)
H C
H
S
H
S C
H
H
H H C
H
S
H
O
H
H C
H
S
H
+
Dimethyl disulfide (DMDS) Methanesulfenic
acid
Methanethiolate
radical
+ OH
H C
H
S
H
S C
H
H
HH C
H
S
H
2
Dimethyl disulfide (DMDS)Methanethiolate
radical
+ h ν
Biogenic SulfurHydrogen sulfide oxidation (11.65)
Hydrogen sulfide radical reaction (11.66)
Sulfur dioxide production from sulfur oxide (11.59)
S
HH
S
H
Hydrogen
sulfide
Hydrogen
sulfide radical
+ OH
H2
O
+ O2
S
H
OH
Hydrogen
sulfide radical
Sulfur
monoxide
S O
S
OO
OSulfur
monoxide
S O
Sulfur
dioxide
+ O2
Volcanic SulfurSulfur monoxide production from carbonyl sulfide (11.68)
(11.69)
(11.70)
+ OHO C S
S
H
Hydrogen sulfide
radical
+ CO2
Carbonyl
sulfide
Carbonyl
sulfide
O C S +
Carbon
monoxide
Atomic
sulfur
+ h ν λ < 260 nmCO S
O
+ O2
Sulfur
monoxide
S O
Atomic
sulfur
S
Volcanic SulfurSulfur oxide production from carbon disulfide (11.71)
(11.72)
(11.73)
+ OHS C S
S
H
O C S+
Carbon
disulfide
Hydrogen sulfide
radical
Carbonyl
sulfide
S C S +C S
Carbon
disulfide
Carbon
monosulfide
Atomic
sulfur
+ h ν S λ < 340 nm
+ O2
C S
Carbon
monosulfide
+ OO C S
Carbonyl
sulfide
Urban PhotochemistryOzone production in smog (11.75-8)
NO + ROG * NO2
+ ROG **
NO + O3
NO2
+ O2
NO2
+ h ν + NO O λ < 420 nm
O + O2
+ M O3
+ M
0 0.5 1 1.5 2
0
0.05
0.1
0.15
0.2
0.25
ROG (ppmC)
NO
x
(g) (ppmv)
0.4
0.32
0.24
0.16
0.08 = O
3
(g), ppmv
Ozone Isopleth
Fig. 11.1Contours are ozone (ppmv)
NO
x (pp
mv)
0.24
0.08
0.32
0.16
Sea Breeze
Fig. 11.2
0
1
2
3
4
5
6
7
0 6 12 18 24 30 36 42 48 54 60 66 72
Wind speed (m s
-1
)
Hour of day
Day 1 Day 2
Day 3
Win
d sp
eed
(m s
-1)
Source/Receptor Regions in Los Angeles
0
0.1
0.2
0.3
0 6 12 18 24
Volume mixing ratio (ppmv)
Hour of day
O
3
NO
2NO
Central Los Angeles
August 28, 1987
Vol
ume
mix
ing
rati
o (p
pmv)
Fig. 11.2
0
0.1
0.2
0.3
0 6 12 18 7224
Volume mixing ratio (ppmv)
Hour of day
O
3
NO
2
NO
San Bernardino
August 28, 1987
Vol
ume
mix
ing
rati
o (p
pmv)
Daily Los Angeles Emission (1987)
Table 11.2
Gas Emission (tons/day) Percent of totalCarbon monoxide 9796 69.3
Nitric oxide 754Nitrogen dioxide 129Nitrous acid 6.5
Total NOx+HONO 889.5 6.3Sulfur dioxide 109Sulfur trioxide 4.5
Total SOx(g) 113.5 0.8Alkanes 1399Alkenes 313Aldehydes 108Ketones 29Alcohols 33Aromatics 500Hemiterpenes 47
Total ROGs 2429 27.2Methane 904 6.4
Total emission 14,132 100
Percent Emission by Source
Nitric oxide from combustion (11.79)
N N O O N O+ 2+ heat
Table 11.4
Source Category CO(g) NOx(g) SOx(g) ROG Stationary 2 24 38 50Mobile 98 76 62 50Total 100 100 100 100
Organic Gases Emitted in Greatest Abundance in Los Angeles (1987)
Table 11.3
1. Methane2. Toluene3. Pentane4. Butane5. Ethane6. Ethylene7. Octane8. Xylene
9. Heptane10. Propylene11. Chloroethylene12. Acetylene13. Hexane14. Propane15. Benzene
Most Important Gases in Smog in Terms of Ozone Reactivity and Abundance
Table 11.6
1. m- and p-Xylene2. Ethene3. Acetaldehyde4. Toluene5. Formaldehyde6. i-Penane7. Propene8. o-Xylene9. Butane10. Methylcyclopentane
Lifetimes of ROGs Against Loss in Urban Air
Table 11.5
ROG Species Phot. OH HO2 O NO3 O3 n-Butane --- 22 h 1000 y 18 y 29 d 650 ytrans-2-butene --- 52 m 4 y 6.3 d 4 m 17 mAcetylene --- 3 d --- 2.5 y --- 200 dFormaldehyde 7 h 6 h 1.8 h 2.5 y 2 d 3200 yAcetone 23 d 9.6 d --- --- --- ---Ethanol --- 19 h --- --- --- ---Toluene --- 9 h --- 6 y 33 d 200 dIsoprene --- 34 m --- 4 d 5 m 4.6 h
OH Sources in Polluted AirEarly morning source (11.80)
Mid-morning source (11.81)
(11.82)
(11.83)
λ < 400 nmOH + NOHONO + h ν
HCHO + h ν λ < 334 nm + H HCO
M
H + O2
HO2
HCO + O2
HO2
+ CO
(11.84)NO + HO
2NO
2 + OH
Hydroxyl Rad. Sources in Polluted Air
Afternoon source (11.88)
(11.86)
O3
+ h ν O2
+ (O1
D ) λ < 310 nm
O(1
D ) + H2
O 2 OH
Alkene Reaction With Hydroxyl Radical
Ethene oxidation (11.87)
C C
H
H
H
H
Ethene
C C
H
H
H
H
Ethanyl radical
OH
C C
H
H
H
H
Ethanolperoxy
radical
OH
O
O
C C
H
H
H
H
Ethanoloxy
radical
OH
O
+ OH, M + O2
, M
NO2
+ NO
Alkene Reaction With Hydroxyl Radical
Ethanoloxy radical oxidation (11.88)
Formaldehyde
C O
H
H
C C
H
H
H
H
Ethanoloxy
radical
OH
O
C C
H
H
O
H
OH
Glycol aldehyde
72% 2
28%
+ O2
HO2