Global, Regional, and Urban Climate Effects of Air Pollutants
Mark Z. Jacobson
Dept. of Civil & Environmental Engineering
Stanford University
Modeled CO2(g) and Modeled v Measured Ocean pH 1751-2003
280
300
320
340
360
380
8.1
8.15
8.2
8.25
8.3
1750 1800 1850 1900 1950 2000
DataModel
pH-500Tg-C/yBBemis
CO 2
mix
ing
ratio
(pp
mv)
Surface ocean pH
Year
CO
2(g)
mix
ing
rati
o (p
pmv)
Surface ocean pH
Data from Friedli et al. (1986) and Keeling and Whorf (2003)
Modeled Ocean Profiles 2004; 2104 Under SRES A1B Emission Scenario
7.8 7.9 8 8.1 8.2
0
500
1000
1500
2000
20042104
pH
Dep
th (
m)
(a)
1.9 2 2.1 2.2 2.3
0
500
1000
1500
2000
20042104
Total inorganic carbon (mmol/kg)
Dep
th (
m)
(b)
Dep
th (
m)
Dep
th (
m)
Effect of CO2(g) on Atmospheric Acids
10-18
10-16
10-14
10-12
10-10
10-8
10-6
2000 2020 2040 2060 2080 2100
Ammonia x (-1)Nitric acidHydrochloric acidSulfur dioxide
Mix
ing
rati
o (p
pbv)
Year of simulation
Diff. between A1B base and today
(d)
Mix
ing
rati
o (p
pbv)
Interstitialaerosol
Liquid Ice
Shrinkage, precipitation, rainout, and washout
Cloud evaporation --> interstitial aerosol plus evaporated cores
Condensation/deposition of water vapor onto aerosol particlesCoagulation: Aerosol-aerosol Aerosol-liquid Aerosol-ice Aerosol-graupel Liquid-liquid Liquid-ice Liquid-graupel Ice-ice Ice-graupel Graupel-graupelGas dissolution. aqueous chemistry, hom.-het. freezing, contact freezing
Graupel
Dissolved,reacted
gas
Aerosol-particle
core
Coagulatedaerosolparticle
Gas dissolutionand aerosol-
particlecoagulation
during precip.(washout)
Rainoutof core andexisting gas
Cloud Microphysical and Chemical Processes
Comparison of ff BC Climate Responses1. Jacobson (JGR 107, D19, 2002). Size resolved (1 distribution) multi-component aerosols, size-
resolved cloud formation on aerosols, size-resolved treatment of first and part of second indirect effects, climatological snow/ice albedo, emissions of Cooke et al. (1999), 2-D ocean module, many feedbacks.
• Fossil fuel BC+OM: +0.3 K (5-y average)+0.35 K (last year) Range of all simulations (+0.15 to +0.5)
2. Ibid. (JGR 2004, in press). Same as (1) but treated first and second indirect effects, calculated snow/ice albedo, used early Bond et al. (2004) inventory.
• Fossil fuel + biofuel BC+OM: +0.27 K (10-y avg. snow contrib. +0.06 K)
3. Ibid. Recent results. Same as (2) but used most recent Bond et al (2004) emission,, used two distributions (emitted ff+bf BC+OM and emitted other + heterocoagulated BC) and 10 layers of energy diffusion to deep ocean.
• Fossil fuel + biofuel BC+OM: +0.29 K (6-y avg.)
Ten-Year-Avg. Globally-Averaged Temperature Profile Differences
-0.4 -0.2 0 0.2 0.4
1
10
100
1000
-0.4-0.2 0 0.2 0.4
Temperature (K)with minus without ff+bf BC+OM
Pres
sure
(hP
a) LayerC
umul
ativ
e
Pre
ssur
e (h
Pa)
With snow/sea ice absorption and with-w/o ff+bf BC+OM
-0.4 -0.2 0 0.2 0.4
1
10
100
1000
-0.4-0.2 0 0.2 0.4
Temperature (K)w-w/o BC snow+sea ice absorption
Pre
ssur
e (h
Pa)
Layer
Cum
ulat
ive
Pre
ssur
e (h
Pa)
Contribution of BC absorption by snow/sea ice
-2
-1.5
-1
-0.5
0
0.5
2000 2020 2040 2060 2080 2100Coo
ling
(K
) af
ter
elim
inat
ing
anth
. em
iss.
Year
f.f. BC+OM
CO2(50y)
CH4(10y)
CO2(95y)
CO2(30y)
Temperature Changes Due to Eliminating Emission of Anthropogenic CO2, CH4, and f.f. BC+OM
Coo
ling
(K
) af
ter
elim
inat
ing
ant
hrop
ogen
ic e
mis
sion
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10Temperature difference (K) w-w/o ghg+aerosols
Observed and Modeled Temp. Diff. w-w/o GHG and Aerosols
Schneider and Held (2001)L
atit
ude
(deg
rees
)
(4 y an. avg.)
(January only
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6Temperature difference (K) w-w/o ghg
Modeled (4 y avg.) Temp. Diff. w-w/o Anth. GHG alone
Lat
itude
(de
gree
s)
Modeled (4 y avg.) and Radiosonde Vertical Temp. (K) dif. w-w/o GHG and Aerosols
Radiosonde dataAngell et al. (1999)
-2
-1.5
-1
-0.5
0
0.5
1
1960 1970 1980 1990 2000
Tem
pera
ture
dev
iati
on (
oC
)
Year
100-30 mb
300-100 mb
850-300 mb
Near-surface
Tem
pera
ture
dev
iatio
n (
K)
-75 -50 -25 0 25 50 75
50
40
30
20
10
0
Latitude (degrees)
Alt
itud
e (k
m)
-6 -5 -4 -3 -2 -1 0 1 2 3Temperature difference (K) w-w/o ghg+aerosols
Alt
itud
e (k
m)
300-100 mb ≈ 9-16 km100-30 mb ≈ 16-24 km
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.0005 0.0010 0.0015August column BC dif. (g/m2) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.00000 0.00025 0.00050 0.00075 0.00100February column BC dif. (g/m2) w-w/o anth. aer.
Feb. & Aug. California Column BC Dif. w-w/o Anth. Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.0025 0.0050 0.0075August column POM dif. (g/m2) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.0000 0.0025 0.0050 0.0075February column POM dif. (g/m2) w-w/o anth. aer.
Column POM Dif. w-w/o Anth. Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.002 0.004 0.006August column SOM dif. (g/m2) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.00000 0.00005 0.00010 0.00015 0.00020February column SOM dif. (g/m2) w-w/o anth. aer.
Column SOM Dif. w-w/o Anth. Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.000 0.001 0.002February column S(VI) dif. (g/m2) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.000 0.001 0.002 0.003August column S(VI) dif. (g/m2) w-w/o anth. aer.
Column S(VI) Dif. w-w/o Anth. Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.000 0.001 0.002August column NO3- dif. (g/m2) w-w/o anth. aer
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.0000 0.0005 0.0010February column NO3- dif. (g/m2) w-w/o anth. aer.
Column NO3- Dif. w-w/o Anth. Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.00000 0.00025 0.00050 0.00075February column NH4+ dif. (g/m2) w-w/o anth. aer.
Column NH4+ Dif. w-w/o Anth. Aer.
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.0000 0.0005 0.0010 0.0015August column NH4+ dif. (g/m2) w-w/o anth.a er.
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.000 0.025 0.050 0.075August column total aerosol dif. (g/m2) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.000 0.025 0.050 0.075February column aerosol LWC dif. (g/m2) w-w/o anth. aer.
Column Aerosol LWC Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.000 0.025 0.050 0.075August column total aerosol dif. (g/m2) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-0.025 0.000 0.025 0.050 0.075February column total aerosol dif. (g/m2) w-w/o anth. aer.
Column Total Aerosol Dif. w-w/o Anth. Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.0 0.1 0.2 0.3August aerosol 550 nm optical depth dif. w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-0.0 0.1 0.2 0.3February aerosol 550 nm optical depth dif. w-w/o anth. aer.
Aerosol 550 nm Optical Depth Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0 5 10August cloud optical depth dif. w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0 5 10 15February cloud optical depth dif. w-w/o anth. aer.
Cloud 550 nm Optical Depth Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
Cloud 550 nm Scattering Optical Depth Profile Dif.
-0.1 0 0.1 0.2 0.3 0.4 0.5 0.6
100
1000
Feb.Aug.
-0.10 0.10.20.30.40.50.6
Cloud scattering optical depthw-w/o anth. aer.
Pre
ssur
e (h
Pa)
CaliforniaP
ress
ure
(hP
a)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-20 -10 0 10August down-up surface solar dif. (W/m2) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-30 -20 -10 0 10 20February down-up surface solar dif. (W/m2) w-w/o anth. aer.
Down-Up Surface Solar Radiation Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-6 -3 0 3 6August down-up surface thermal-IR dif. (W/m2) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-5 0 5 10 15February down-up thermal-IR dif. (W/m2) w-w/o anth. aer.
Down-Up Surface Thermal-IR Radiation Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-5 -4 -3 -2 -1 0 1 2
100
1000
-5 -4 -3 -2 -1 0 1 2
Irradiance (W/m2)w-w/o anth. aer.
Pre
ssur
e (h
Pa)
California
Feb
. sol.A
ug
. so
l.
Feb
. TIR
Au
g. T
IR
Irradiance Profile Dif. Over California
Pre
ssur
e (h
Pa)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-1.4 -1.2 -1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6February near-surface temperature dif. (K) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-0.4 -0.3 -0.2 -0.1 -0.0 0.1 0.2 0.3August near-surface temperature dif. (K) w-w/o anth. aer.
Near-surface Temperature Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
32.5 35.0 37.5 40.0
10
8
5
2
0
Latitude (degrees)A
ltit
ude
(km
)
-0.1 0.0 0.1August zonal temperature dif. (K) w-w/o anth. aer.32.5 35.0 37.5 40.0
10
8
5
2
0
Latitude (degrees)
Alt
itud
e (k
m)
-0.1 0.0 0.1February zonal temperature dif. (K) w-w/o anth. aer.
Zonal Temp. Profile Dif. w-w/o Anth.Aer.
Alt
itud
e (k
m)
Alt
itud
e (k
m)
-0.1 -0.05 0 0.05
100
1000
Feb.Aug.
-0.1 -0.05 0 0.05
Temperature (K)w-w/o anth. aer.
Pre
ssur
e (h
Pa)
California
Temperature Profile Dif. Over California
Pre
ssur
e (h
Pa)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-0.04 -0.02 0.00 0.02August near-surface relative humidity dif. (fract.) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-0.030 -0.018 -0.007 0.005 0.017 0.028 0.040February near-surface RH dif. (fract.) w-w/o anth. aer.
Near-surface RH Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
32.5 35.0 37.5 40.0
10
8
5
2
0
Latitude (degrees)
Alt
itud
e (k
m)
-0.01 0.00 0.01August zonal relative humidity dif. (frac.) w-w/o anth aer.
32.5 35.0 37.5 40.0
10
8
5
2
0
Latitude (degrees)
Alt
itud
e (k
m)
-0.015 -0.010 -0.005 0.000 0.005 0.010February zonal relative humidity dif. (frac.) w-w/o anth. aer.
Zonal RH Dif. w-w/o Anth.Aer.
Alt
itud
e (k
m)
Alt
itud
e (k
m)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-0.005 0.000 0.005August cloud LWC dif. (kg/m2) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-0.0050 -0.0025 0.0000 0.0025 0.0050February cloud LWC dif. (kg/m2) w-w/o anth. aer.
Cloud LWC Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-4 10-6 -2 10-6 0 2 10-6
100
1000
Feb.Aug.
-4 10-6-2 10
-60 2 10
-6
Cloud ice (kg/m2)w-w/o anth. aer.
Pre
ssur
e (h
Pa)
California
0 0.0002
100
1000
Feb.Aug.
0 0.0002
Cloud LWC (kg/m2)w-w/o anth. aer.
Pre
ssur
e (h
Pa)
California
Cloud Liquid and Ice Profile Dif. Over California
Pre
ssur
e (h
Pa)
Pre
ssur
e (h
Pa)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.00 1.25 2.50 3.75 5.00February baseline precipitation (mm/day)
Modeled vs. Measured Feb. 1999 Precipitation
Lat
itud
e (d
egre
es)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.00 1.25 2.50 3.75 5.00February baseline precipitation (mm/day)
Modeled Feb. 1999 vs. Measured Feb. Clim. Prec.
Lat
itud
e (d
egre
es)
Data courtesy of Guido Franco
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-0.2 -0.1 0.0 0.1 0.2August precipitation dif. (mm/day) w-w/o anth. aer.
-0.2 -0.1 0.0 0.1 0.2February precipitation dif. (mm/day) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
-0.2 -0.1 0.0 0.1 0.2February precipitation dif. (mm/day) w-w/o anth. aer.
Precipitation Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-0.2 -0.1 0.0 0.1 0.2August precipitation dif. (mm/day) w-w/o anth. aer.
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.0000 0.0060 0.0120 0.0180 0.0240 0.0300August baseline BC in precipitation (g/kg)
-125.0 -122.5 -120.0 -117.5
40.0
37.5
35.0
32.5Lat
itud
e (d
egre
es)
0.000 0.002 0.004 0.006February baseline BC in precipitation (g/kg)
Baseline BC in precipitation
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
0.00 0.01 0.02 0.03 0.04August column total aerosol dif. (g/m2) w-w/o anth. aer.
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
0.00 0.01 0.02 0.03 0.03 0.04 0.05 0.06February column total aerosol dif. (g/m2) w-w/o anth. aer.
SCAB Column Total Aerosol Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
0.00 0.05 0.10 0.15August aerosol optical depth dif. w-w/o anth. aer.
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
0.03 0.08 0.13 0.18February aerosol optical depth dif. w-w/o anth. aer.
SCAB Aerosol Optical Depth Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5August cloud optical depth dif. w-w/o anth. aer.
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-1 0 1 2 3 4February cloud optical depth dif. w-w/o anth. aer.
SCAB Cloud Optical Depth Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-0.02 0 0.02 0.04 0.06 0.08
100
1000
Feb.Aug.
-0.02 0 0.020.040.060.08
Cloud scattering optical depthw-w/o anth. aer.
Pre
ssur
e (h
Pa)
South CoastAir Basin
Cloud 550 nm Scattering Optical Depth Profile Dif.
Pre
ssur
e (h
Pa)
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-15.0 -12.5 -10.0 -7.5 -5.0 -2.5 0.0 2.5August down-up surface solar dif. (W/m2) w-w/o anth. aer.
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-14 -12 -10 -8 -6 -4 -2 0 2 4 6 8 10February down-up surface solar dif. (W/m2) w-w/o anth. aer.
SCAB Down-Up Surface Solar Radiation Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-2.00 -1.50 -1.00 -0.50 0.00August downard UV radiation dif. (W/m2) w-w/o anth. aer.
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-1.25 -1.00 -0.75 -0.50 -0.25 0.00 0.25February downward UV dif. (W/m2) w-w/o anth. aer.
SCAB Downward UV Radiation Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-2.5e-05 0.0e+00 2.5e-05August near-surface OH dif. (ppbv) w-w/o anth. aer.
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-0.000015 -0.000010 -0.000005 0.000000February near-surface OH dif. (ppbv) w-w/o anth. aer.
SCAB Near-Surface OH Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-4 -2 0 2 4August down-up surface thermal-IR dif. (W/m2) w-w/o anth. aer.
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0February down-up surface thermal-IR (W/m2) w-w/o anth. aer.
SCAB Down-Up Surface Thermal-IR Radiation Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-4 -3 -2 -1 0 1
100
1000
-4 -3 -2 -1 0 1
Irradiance (W/m2)w-w/o anth. aer.
Pre
ssur
e (h
Pa)
South CoastAir Basin
Feb
. so
l.
Au
g. s
ol.
Feb. TIR
Au
g. T
IR
Irradiance Profile Dif. Over SCAB
Pre
ssur
e (h
Pa)
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-0.2 -0.1 0.0 0.1 0.2August near-surface temperature dif. (K) w-w/o anth. aer.
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-0.15 -0.10 -0.05 -0.00 0.05 0.10 0.15February near-surface air temperature dif. (K) w-w/o anth. aer.
SCAB Near-Surface Temperature Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-0.02 0 0.02
100
1000
-0.02 0 0.02
Temperature (K)w-w/o anth. aer.
Pre
ssur
e (h
Pa)
South CoastAir Basin
Feb.
Aug.
Temperature Profile Dif. Over SCAB
Pre
ssur
e (h
Pa)
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
0.0 0.3 0.7 1.0 1.4 1.7 2.1 2.4 2.8August baseline precipitiaton (mm/day)
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5February baseline precipitation (mm/day)
SCAB Baseline Precipitation
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-0.3 -0.2 -0.1 -0.0 0.1 0.2 0.3August precip. dif. (mm/day) w-w/o anth. aer.
-119 -118 -117 -116
34.5
34.0
33.5
33.0
Lat
itud
e (d
egre
es)
-0.3 -0.2 -0.1 -0.0 0.1 0.2 0.3February precipitation dif. (mm/day) w-w/o anth. aer.
SCAB Precipitation Dif. w-w/o Anth.Aer.
Lat
itud
e (d
egre
es)
Lat
itud
e (d
egre
es)
Summary• Globally-averaged surface ocean pH may have decreased from about
8.25 to 8.14 from 1751 to 2004 Under the SREAS A1B emission scenario, pH may decrease to 7.85 in 2100, for an increase in the hydrogen ion by a factor of 2.5 since 1751. Ocean acidification may increase concentrations of atmospheric acids and decrease those of bases, although the magnitude is uncertain.
• Three global simulation results suggest a warming due to ff+bf BC of +0.25 to +0.3 K in the 5- to 10-year average with a range of +0.15 K to +0.5 K
• Maximum warming and cooling due to anthropogenic GHGs and aerosols exceed those of GHGs alone. Aerosols act on top of GHGs to enhance extreme warm and cool climate conditions.
• Modeled aerosol particles and gas-phase precursors appear to decrease precipitation in mountainous regions and increase it beyond the mountains, cool surface-air temperatures, slightly increase atmospheric temperatures, reduce solar and UV radiation and OH, and increase thermal-IR radiation to the surface in California.