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.