Center for Global and Regional Environmental Research, The University of Iowa, Iowa City, USA

Aerosols are Pervasive Throughout Asian
Environments
Mineral Dust
BC from Pollution & Fires

Generation of inorganic and organic aerosols by gas-to-particle conversion and nucleation
A Key Science Issue: Chemistry/Aerosol/Regional
Climate Coupling
Radiative Forcing
Anthropogenic Biogenic Tropospheric O
3
Stratospheric input
Gas-phase Tropospheric
Chemistry
Flux of gaseous species to clouds
Heterogeneous
NOx/NOy chemistry
Free radical
Scavenging ?
Alteration of
Actinic flux
Cloud processing
Tropospheric
Clouds
Tropospheric
Aerosols
CCN
Direct effect
Sea salt
Mineral dust
Biomass burning particles
NH
3
Sulfates (via gas-phase chemistry)
Carbonaceous particles
Radiative Forcing
Alteration of cloud albedo
(indirect effect)
Cirrus
Stratus modified after J.H.Seinfeld 1999

• Increase SO
2 to sulfate conversion rates.
• Increase the importance of dry deposition.
• Decrease the lifetime of SO x
, NO y and VOC?
• Control the partitioning of semi-volatile species (e.g.,
HNO
3
).
• Influence precipitation pH.
• Provide reaction channels which may: recycle No x
; produce particulate nitrate; make longer chain VOCs; provide radical sources; and indirectly/directly Perturb O
3
; and alter water uptake.
• Alter photolysis rates.

MODELING
FIELD
STUDY
LABORATORY
(Vicki Grassian
–leader)
•3D STEM-III transport/chemistry/deposition model
•Dynamics of Aerosol Processes
•Combined Kinetic/Thermodynamic
Approach
•New Approach for Secondary
Organic Aerosol Partitioning
•Sensitivity Analysis and Improved
Numerical Methods
•Spectroscopic Measurements
•Detailed Reaction Mechanisms
•Kinetic Measurements
•Surface Coverages
• Adsorption Isotherms
Can change the chemical balance of the atmosphere in two ways
Sink
NO
2
NO
2
+
Reactive Surface
NO
2
+
O
+ NO
H(a) + NO
2
HONO

INTERACTIONS OF SO
2
WITH MINERAL AEROSOL CHANGE
SULFATE SIZE DISTRIBUTION AS WELL AS THE CHEMICAL
LIFETIMES OF SULFUR. THESE INTERACTIONS HAVE
IMPLICATIONS FOR RADIATIVE FORCING
Song et al., JGR in press

Calculated Fine and Coarse Mode Aerosol Distributions in the Boundary Layer; PEM-WEST B

Calculated Fine and Coarse Mode Aerosol Distributions in the
Boundary Layer; PEM-WEST B

Calculated Fine and Coarse Mode Aerosol Distributions at 5 km;
PEM-WEST B

Calculated Fine and Coarse Mode Aerosol Distributions at 5 km;
PEM-WEST B

% Decrease in HO
2 levels due to RXNs on Mineral Aerosol
(May 1987)

NO x
3
+ H x
O y
Rxns; Direct O
3
:
Rxn; and Combination

Nitric Acid Reactions with Calcium Carbonate are not Limited to the Surface, and Change the Water Uptake Properties and Particle
Morphology
TEM Images of CaCO
3
Particles
CaCO
3
0.5 
HNO
3
Reacted
CaCO
3
Goodman et al.,
JGR, 105:29053,
2000

STEM on-line TUV overview
TUV TOP
80km
Overtop O
3
=
STEM TOP
15km
Ice cloud
Water cloud
Inputted from
STEM 3-D field
Surface reflection absorption by gas-phase species
O
3
, SO
2 and NO
2
O
3
(Dobson) below STEM top height
EP/TOMS Total Ozone (Dobson )
Sea Salt
Output:
30 kinds of
J-values for SAPRC99
Dust
Black Carbon
Organic Carbon mechanism
Sulfate
Other PM2.5 and Other PM10

HO
2
HO
NO
3
N
2
O
5 h n
H
2
O
HNO
3
O
2 h n
O
3
HO
HO
2
O
2
HO
RO
NO
2 h n
CH
3
COO
2
Mineral Optical Depth
O
3
HO
2
RO
2
NO
Emission
CH
3
COO
2
NO
2
Fall
Impact of Aerosols on the
Photochemical Oxidant
Cycle Through Photolysis
Rates
Season
Winter
Spring
Summer
Aerosol
D
Sulfate
D
Soot
D
Mineral
D
TSP impact on O
3
% % % %
-
+
Mean
\
18.9
\
48.6
\
13.2
-8.6
-25.8
-5.8
\
58.7
-33.0
-
+
Mean
1.3
\
13.1
24.4
\
9.7
-3.7
-11.1
-3.2
\
36.8
-16.8
-
+
Mean
1.5
\
13.7
25.4
\
8.3
-4.0
-12.9
-3.0
\
37.6
-19.1
-
+
Mean
\ \
15.5
27.3
\
9.2
-6.1
-13.5
-3.8
\
40.3
-20.6
NO x
NMHC
O
3
HO x
UVB
%Change NO
2
Photolysis
Ozone variations (%) due to dust

What is the Importance of Heterogeneous Chemistry on
Mineral Aerosol Surfaces in the Troposphere?
Answer Requires :
• Knowing what chemistry occurs on/in the aerosol.
• Quantifying mineral surfaces in space and time.
• Assessing how mineral aerosols age; and how surfaces activate/deactivate, take on water, etc.
• Quantifying aerosol /radiation interactions.
• Resolving chemical composition as a function of size.

 4%/yr urban growth rate in
Asia-Pacific region
 23 megacities in 1995 (17 in developing countries) to 36 in
2025 (23 in Asia)
 Asia presently has ~1 billion urban dwellers, projected to grow to ~3 billion in 2025

10 Asian Megacities will account for ~40% of GNP in
2025

Each 1 million urban inhabitants emit average of
25,000 tons of CO
2 every day
(six times global per capita average)

Indoor and Outdoor air pollution pose severe human health concerns

100%
80%
60%
40%
20%
0%
D ha ka
Be iji ng
Sh an gh ai
C ho ng qi ng
M um ba i
Ja ka rta
Se ou l
Ba ng ko k
Others
Gas
Fuel Oil
Biofuel
Coal
100%
80%
60%
40%
20%
0%
D ha ka
Be iji ng
Sh an gh ai
C ho ng qi ng
M um ba i
Ja ka rta
Se ou l
Ba ng ko k
OTHER
PP
TRAN
DOM
IND
CON

% Contribution of Megacities to Total Sulfur Deposition
50
40
30
20
10
0
-10
-20
60 70 80 90 100 110 120 130 140 150
40
30
20
10
5
60
50

1200
1000
800
600
1975
1980
1990
1995
2000
400
200
0
D ha ka
Be iji ng
Sh an gh ai
C ho ng qi ng
M um ba i
Ja ka rta
Se ou l
Ba ng ko k
(b)
400
300
200
100
0
800
700
600
500
D ha ka
2010
2010maxf
2020
2020maxf
Be iji ng
Sh an gh ai
C ho ng qi ng
M um ba i
Ja ka rta
Se ou l
Ba ng ko k
Figure 2.
Comparison of SO
2
Emissions from the Megacities of Asia, ktons/year
(a) For year 1975, 1980, 1990, 1995 and 2000
(b) For year 2010 and 2020 from RAINS-Asia 7.52

32 o
30 o 36’
120 o 36’
Shanghai
East China
Sea
Shanghai Province
122 o
 Forward looking policies which anticipate growth in environmental growth and/or retrofitting are most cost-effective.

Policy trajectories include
(example): 1995 - distant siting
(50 km to 75km); 2000 - ESP, coal washing; 2010 - 2050 - fabric filters and low-NOx burners.

IGCC technology for new power plants and relocation of major industrial estates and power plants to outside the city limits.

Scenario ==>
% Emission Reduction
Sulfur
NOx
TSP
PM10
PM2.5
Scenario ==>
Total # of Deaths Avoided
Total # of Chronic Bronchitis Cases Avoided
Total # of Hospital Visits Avoided
Total # of Emergency Hospital Visits Avoided
Total # of Hospital Admissions Avoided
Total Control Costs (US $ in millions)
Total Benefits Due to Human Impacts Avoided (in millions US $)
Median
Health Benefit to Scenario Cost Ratio
C1
Industrial
14
6
9
12
13
C1
1771
1106
60752
30603
27433
94
106 - 887
265
1.1 - 9.4
C2
Power Sector
41
13
3
4
4
C2
2789
1740
95619
48166
43177
395
168 - 1, 396
419
0.4 - 3. 5

Ambient Air Quality Curve in Shanghai mg/m 3
0. 35
0. 3
0. 25
0. 2
0. 15
0. 1
0. 05
0
1991 1992 1993 1994 1995 1996 1997 1998 1999
TSP
NOx
SO 2
Concentration Change of Major Air Pollutants in Urban
Area of Shanghai from 1991 to 1999

Air Pollution and Climate Issues are Intimately Linked
China
Emissions in 2000 1 (Tg)
D in
China’s emissions
(2000 –
1995)
(Tg)
Total global fossil fuel emission ca~1995
(Tg)
Change in
China’s emissions as
% of global total anthropogenic fuel combustion
(%)
Temp.
Response function
D T/ D Emissions
(K/Tg) 2,4
Estimated
Change in global temperatures due to changes in
China’s emissions between 1995 and 2000
(K) 3,4
SO
2
20.8
-4.95 134 -3.7% -8.2 10 -3 +0.04
BC 0.91
-0.43 5.1
-8.4% 6.5 10 -2 -0.026
CO
2
CH
4
3,218
33.4
-109 29,700
+1.16 360
-0.037%
+0.32%
3.0 10 -5 -0.003
7.5 10 -4 +0.001
Net change: S = +0.012

Urban Air
Pollution
Control
Policies and
Technical
Options
Bombay
Shanghai
Urban Air
Quality
Management
• Megacities feel the change first.
•
Health impacts as a primary measure, urban centers will react to policy measures faster than a province or a region.
•
Important challenge is how to integrate climate and urban air quality in a manner that enables the evaluation of complex policies.