Transcript Presentation Slides for Chapter 11, Part 1 of Fundamentals of Atmospheric Modeling 2nd Edition Mark Z.

Presentation Slides
for
Chapter 11, Part 1
of
Fundamentals of Atmospheric Modeling
2nd Edition
Mark Z. Jacobson
Department of Civil & Environmental Engineering
Stanford University
Stanford, CA 94305-4020
[email protected]
March 21, 2005
Types of Gases
Inorganic gases
Contain O, N, S, Cl, Br, and maybe H or C, but not both
Nitric oxide -- N O
Carbon dioxide -- O C O
Organic gases
Contain both H and C, but may also contain other atoms
O
Formaldehyde --
H
C
H
Acetone --
H
H
O
H
C
C
C H
H
Peroxyacetylnitrate --
H
H
H
C
H
O
O
C
O
O
N
O
Hydrocarbons
Organic gases that contain only hydrogen and carbon
Alkanes - Carbons bonded by a single bond
Propane --
H
H
H
H
C
C
C
H
H
H
H
Cycloalkanes - A ring of alkanes
Cyclobutane --
H2C
CH2
H2C
CH2
Alkenes - Carbons bonded by a double bond
H
Ethene (ethylene) --
H
C
H
C
H
Hydrocarbons
Aromatics - Carbons that form a benzene ring
CH 3
Toluene --
Terpenes - Biogenic hydrocarbons
Isoprene --
H
C
H2C
CH3
C
CH2
Definitions
Non-methane hydrocarbons (NMHC)
Hydrocarbons, except for methane
Oxygenated hydrocarbons
Hydrocarbons 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)
NO + O3
NO2 + O2
(11.2)
NO2 + h
NO + O
 < 420 nm
(11.3)
O + O2 + M
O3 + M
Time rate of change of nitrogen dioxide
dNO 2 
(11.4)
 k1NOO 3  J NO 2 
dt
Steady state --> photostationary state relationship
O 3
J NO 2 
k1NO
(11.5)
Photostationary State Relationship
Example 11.1:
Estimate ozone mixing ratio when
pa
= 1013 hPa
NO = 5 pptv
k1
= 1.8x10-14 cm3 molec.-1 s-1
Solution:
[O3] = 1.1x1012 molec. cm-3
Nd
= 2.46 x 1019 molec. cm-3
O3 = 44.7 ppbv
T
= 298 K
NO2 = 10 pptv
J
= 0.01 s-1
Other Reactions Affecting Ozone
Photodissociation of ozone
O3 + h
(11.6)
 < 310 nm
O2 + O(1D)
(11.7)
O3 + h
 > 310 nm
O2 + O
Conversion of excited to ground-state atomic oxygen
M
O(1D)
O
(11.8)
Hydroxyl Radical Sources
Major
(11.9)
O(1D) + H2O
Minor
2OH
(11.10-13)
HONO + h
OH + NO
 < 400 nm
HNO3 + h
OH + NO2
 < 335 nm
H2O2 + h
2OH
 < 355 nm
HO2 + NO2
 < 330 nm
OH + NO3
< 330 nm
HO2NO2 + h
Scavenging by Hydroxyl Radical
(11.14-17)
OH + O3
HO2 + O2
OH + H2
H2O + H
OH + HO2
OH + H2O2
H2O + O2
HO2 + H2O
Scavenging by Hydroxyl Radical
(11.19-23)
M
OH + NO2
OH + SO2
OH + CO
OH + CH4
HNO3
M
HSO 3
H + CO2
H2O + CH3
Hydroperoxy Radical Production
(11.27)
M
H + O2
HO2
(11.28)
HO2 NO2
M
HO2 + NO2
Hydroperoxy Radical Loss
Hyrdoxyl radical reactions in presence of NO
HO2 + NO
HO2 + NO2
HO2
+
O3
OH + NO2
M
HO2NO2
OH + 2O2
(11.29)
(NO > 10 pptv)
(11.30)
(NO 3-10 pptv)
(11.31)
HO2 + HO2
H2O2 + O2
(NO < 3 pptv)
Nighttime Nitrogen Chemistry
Production of nitrate radical
(11.32)
NO2 + O3
NO3 + O2
Dinitrogen pentoxide formation / decomposition
NO2 + NO3
M
N2O5
(11.33)
Nighttime Nitrogen Chemistry
Dinitrogen pentoxide reaction, photolysis
N2O5 + H2O(aq)
(11.34)
2HNO3(aq)
(11.36)
N2O 5 + h
 < 385 nm
NO2 + NO3
Nitrate radical photolysis (lifetime of minutes)
NO3 + h
(11.35)
NO2 + O
410 nm < < 670 nm
NO + O2
590 nm < < 630 nm
Ozone From Carbon Monoxide
CO + OH
CO2 + H
M
H + O2
NO + HO2
NO2 + h
NO + O
O + O2 + M
HO2
NO2 + OH
 < 420 nm
O3 + M
(11.37-41)
Ozone Formation From Methane
CH4 + OH
H
+ NO
H
H
H
H
+ O2, M
C
H
Methyl
radical
H
C
O
O
H
+ HO2
Methylperoxy
radical
O + O2 + M
O
O
H
HO2
C
H
Formaldehyde
H
H
NO + O
C
+ O2
H
Methoxy
radical
NO2
O2
NO2 + h
(11.42)
CH3 + H2O
C
O
O
H
(11.43)
H
Methyl
hydroperoxide
 < 420 nm (11.40)
O3 + M
(11.41)
Methyl Hydroperoxide Decomposition
(11.44)
+ h
 < 360 nm
H
H
H
H
C O
O H
H
+ O2
C O
OH
H
Methoxy
radical
+ OH
H
Methyl
hydroperoxide
H
H2O
C
O
H
Methylperoxy
radical
O
H
HO2
O
C
H
Formaldehyde
Ethane Oxidation
Methylperoxy radical production and loss
H
H
H
C
C
H
H
Ethane
+ OH
H
H
H2O
H
H
C
C
H
H
Ethyl radical
(11.45)
+ O2, M
H
H
H
C
C
H
H
O
O
Ethylperoxy radical
Ethane Oxidation
(11.46)
+ NO
H H
H
H H
H
C
C
O
NO2
C
H
O
H H
H
H H
+ NO2
H
C
O
C
H
Acetaldehyde
H H
M
C
H
HO2
Ethoxy radical
O
Ethylperoxy radical
C
+ O2
C
O
O
O
N
H H
Ethylperoxynitric acid
O
Propane Oxidation
Methylperoxy radical production and loss
H
H
H
H
C
C
C
H
H
H
+ OH
H
H
H2O
Propane
H
H
C
C
C
H
H
H
+ O2, M
H
n-Propyl radical
+ NO
H
NO2
H
H
H H
C
C
H
H H
C
(11.47)
H
H
C
C
C
H
H
H
O
O
n-Propylperoxy radical
+ O2
O
n-Propoxy radical
H
H
HO2
H
O H
C
C
H
C H
H
Acetone
Formaldehyde/Acetaldehyde Photolysis
Formaldehyde
O
O
H
H
C
+ h
(11.48)
+ H
 < 334 nm
Formyl
radical
C
H
 < 370 nm
CO + H2
Formaldehyde
Acetaldehyde
H
H
C
O
C
H
H
Acetaldehyde
(11.49)
H
+ h
H
C
O
+
H
M ethyl radical
Eormyl radical
O
H
Formyl radical
(11.50)
+ O2
C
H
Formyl
radical
 < 325 nm
C
CO
HO2
Formaldehyde/Acetaldehyde Reaction
Formaldehyde
(11.51)
+ OH
O
H
O
C
C
H
Formaldehyde
H
H2O
Formyl radical
Acetaldehyde
H
H
C
O
(11.52)
+ OH
C
H
H
Acetaldehyde
H
H
H2O
C
O
C
H
Acetyl radical
H
+ O2, M
H
C
H
O
C
O O
Peroxyacetyl
radical
Formaldehyde/Acetaldehyde Reaction
PAN formation
(11.53)
H
+ NO
H
C
O
C
O
H
H
H
C
H
O
NO2
Acetyloxy radical
C
O
Peroxyacetyl
radical
O
H
+ NO2, M
H
C
H
O
C
O O
O
N
O
Peroxyacetyl nitrate
Acetone Photolysis
(11.55)
H
H
O
H
C
C
C H
H
H
Acetone
H
+ h
H
C
H
O
C
H
Acetyl radical
+
H
C
H
Methyl radical
Sulfur Photochemistry
Biogenic 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
S
O
O
Sulfur
dioxide
+ O2
O
+ OH, M
O
S
HO
(11.74)
O
S
O
Bisulfite
HO2
O
O
+ H2O
O
Sulfur
trioxide
S
OH
OH
Sulfuric
acid
DMS Abstraction Pathway
Sulfur dioxide production from dimethyl sulfide (DMS)
(11.56)
H
H
H
C
S
H
+ OH
H
C H
H
H
Dimethyl sulfide (DMS)
NO2
C
H
S
H
+ O2
H
C
H
S
C
H
DM S oxy radical
S
H
C
O
O
H
DMS peroxy radical
O
H
M
O
C
H
H
H
DMS radical
H
H
C
H
H2O
+ NO
H
C
S
+
H
C
H
H
M ethanethiolate
radical
Formaldehyde
DMS Abstraction Pathway
Methanethiolate radical reaction
(11.57)
+ NO
H
H
NO2
H
H
C
H
+ O2, M
S
H
M ethanethiolate
radical
H
C
O*
S
Excited methanethiolate
peroxy radical
S
O
H
M ethanethiolate oxy
radical
O
H
C
H
M
H
C
O
S
O
H
M ethanethiolate
peroxy radical
DMS Abstraction Pathway
Methanethiolate oxy radical reaction
(11.58)
H
M
H
C
+
H
M ethyl
radical
H
H
C
S
O
H
M ethanethiolate oxy
radical
H
O2
C
O
S
O
Sulfur monoxide
H
+ O3
S
O
H
M ethanethiolate
peroxy radical
DMS Abstraction Pathway
Sulfur dioxide production from sulfur oxide
+ O2
S
S
O
Sulfur
monoxide
(11.59)
O
O
Sulfur
dioxide
O
Sulfur dioxide production from sulfur oxide
H
H
C
O
S
O
H
M ethanethiolate
peroxy radical
(11.60)
H
M
H
C
H
M ethyl radical
+
S
O
O
Sulfur dioxide
DMS Addition Pathway
Methanethiolate oxy radical reaction
(11.61)
M
H
H
C
H
H
S
C
+ OH
H
H
H
H
OH H
C
S
H
C
H
H
H
H
C
DM S-OH adduct
S
O
+ H
H
M ethanesulfenic
acid
+ OH, 2O2
H O H
H
Dimethyl sulfide (DM S)
H
H
2HO2
C
S
C
H
O
H
C
H
M ethyl
radical
H
Dimethyl sulfone (DM SO2)
DMS Addition Pathway
Methanesulfenic acid oxidation
H
H
C
H
S
M ethanesulfenic
acid
H
+ OH
O
H
(11.62)
H
H2O
C
S
O
H
M ethanethiolate oxy
radical
DMDS Reaction
OH addition
(11.63)
H
H
H
C
S
S
H
C
H
+ OH
H
H
H
C
H
H
S
O
+
H
H
Dimethyl disulfide (DM DS)
M ethanesulfenic
acid
M ethanethiolate
radical
(11.64)
H
C
H
S
H
Photolysis
H
C
H
S
S
C
H
H
+ h
H
Dimethyl disulfide (DM DS)
2 H
C
S
H
M ethanethiolate
radical
Biogenic Sulfur
Hydrogen sulfide oxidation
+ OH
S
H
(11.65)
S
H
H
H2O
Hydrogen
sulfide
Hydrogen sulfide radical reaction
Hydrogen
sulfide radical
(11.66)
+ O2
S
S
H
O
OH
Hydrogen
sulfide radical
Sulfur
monoxide
Sulfur dioxide production from sulfur oxide
+ O2
S
O
Sulfur
monoxide
S
O
O
O
Sulfur
dioxide
(11.59)
Volcanic Sulfur
Sulfur monoxide production from carbonyl sulfide
O
C
S
S
+ OH
H
Hydrogen sulfide
radical
Carbonyl
sulfide
(11.68)
+ CO2
(11.69)
O
C
S
+ h
CO
Carbonyl
sulfide
S
+
Carbon
monoxide
Atomic
sulfur
(11.70)
+ O2
S
S
Atomic
sulfur
O
 < 260 nm
O
Sulfur
monoxide
Volcanic Sulfur
Sulfur oxide production from carbon disulfide
S
C
S
S
+ OH
+
H
Hydrogen sulfide
radical
Carbon
disulfide
(11.71)
O
C
S
Carbonyl
sulfide
(11.72)
S
C
S
+ h
C
Carbon
disulfide
S
Carbon
monosulfide
+
 < 340 nm
S
Atomic
sulfur
(11.73)
C
S
Carbon
monosulfide
+ O2
O
C
S + O
Carbonyl
sulfide
Urban Photochemistry
Ozone production in smog
NO + ROG*
(11.75-8)
NO2 + ROG**
NO + O3
NO2 + O2
NO2 + h
NO + O
O + O2 + M
O3 + M
 < 420 nm
Ozone Isopleth
0.32
0.32
0.16
0.24
0.24
0.08
0.16
0.1
0.4
3
0.15
0.08 = O (g), ppmv
NO
x x (ppmv)
0.2
NO
(g) (ppmv)
0.25
0.05
0
0
0.5
Contours are ozone (ppmv)
1
1.5
ROG (ppmC)
2
Fig. 11.1
Wind speed (m
-1
-1
s ))
Wind speed (m s
Sea Breeze
7
6
5
4
3
2
1
Day 1
Day 2
Day 3
0
0 6 12 18 24 30 36 42 48 54 60 66 72
Hour of day
Fig. 11.2
Central Los Angeles
August 28, 1987
0.2
NO
NO
2
O
0.1
3
0
0
6
12
18
Hour of day
24
Volume mixing ratio (ppmv)
0.3
Volume mixing ratio (ppmv)
Volume mixing ratio (ppmv)
Source/Receptor Regions in Los Angeles
0.3
San Bernardino
August 28, 1987
0.2
NO
O
3
2
0.1
NO
0
0
6
12
18
Hour of day
24
72
Fig. 11.2
Daily Los Angeles Emission (1987)
Gas
Carbon monoxide
Nitric oxide
Nitrogen dioxide
Nitrous acid
Total NOx+HONO
Sulfur dioxide
Sulfur trioxide
Total SOx(g)
Alkanes
Alkenes
Aldehydes
Ketones
Alcohols
Aromatics
Hemiterpenes
Total ROGs
Methane
Emission (tons/day)
9796
754
129
6.5
889.5
109
4.5
113.5
1399
313
108
29
33
500
47
2429
904
Percent of total
69.3
Total emission
14,132
100
6.3
0.8
27.2
6.4
Table 11.2
Percent Emission by Source
Nitric oxide from combustion
N
N
+ O
Source Category
Stationary
Mobile
Total
O
(11.79)
+ heat
CO(g)
2
98
100
NOx(g)
24
76
100
2 N
SOx(g)
38
62
100
O
ROG
50
50
100
Table 11.4
Organic Gases Emitted in Greatest
Abundance in Los Angeles (1987)
1. Methane
2. Toluene
3. Pentane
4. Butane
5. Ethane
6. Ethylene
7. Octane
8. Xylene
9. Heptane
10. Propylene
11. Chloroethylene
12. Acetylene
13. Hexane
14. Propane
15. Benzene
Table 11.3
Most Important Gases in Smog in Terms
of Ozone Reactivity and Abundance
1. m- and p-Xylene
2. Ethene
3. Acetaldehyde
4. Toluene
5. Formaldehyde
6. i-Penane
7. Propene
8. o-Xylene
9. Butane
10. Methylcyclopentane
Table 11.6
Lifetimes of ROGs Against Loss in
Urban Air
ROG Species
n-Butane
trans-2-butene
Acetylene
Formaldehyde
Acetone
Ethanol
Toluene
Isoprene
Phot.
------7h
23 d
-------
OH
22 h
52 m
3d
6h
9.6 d
19 h
9h
34 m
HO2 O
1000 y 18 y
4y
6.3 d
--2.5 y
1.8 h 2.5 y
----------6y
--4d
Table 11.5
NO3
29 d
4m
--2d
----33 d
5m
O3
650 y
17 m
200 d
3200 y
----200 d
4.6 h
OH Sources in Polluted Air
Early morning source
HONO + h
(11.80)
 < 400 nm
OH + NO
Mid-morning source
HCHO + h
(11.81)
 < 334 nm
H + HCO
M
H + O2
HO2
HCO + O2
HO2 + CO
NO + HO2
NO2 + OH
(11.82)
(11.83)
(11.84)
Hydroxyl Rad. Sources in Polluted Air
Afternoon source
O3 + h
(11.88)
 < 310 nm
O2 + O(1D)
O(1D) + H2O
2 OH
(11.86)
Alkene Reaction With Hydroxyl Radical
Ethene oxidation
H
H
C
+ OH, M
(11.87)
H
C
H
C
H
Ethene
OH
H
H
C
H
Ethanyl radical
+ O2, M
H O + NO
C C O
H
H
NO2
Ethanolperoxy
radical
H
OH
H
OH
C
H
H
C O
H
Ethanoloxy
radical
Alkene Reaction With Hydroxyl Radical
Ethanoloxy radical oxidation
(11.88)
H
72%
H
OH
C
H
H
C O
H
Ethanoloxy
radical
C
2
H
Formaldehyde
+ O2
H
HO2
O
OH
C
28%
H
O
C
H
Glycol aldehyde