Transcript Linking Urban Pollution, Tropospheric Chemistry and

Urban Air Pollution, Tropospheric
Chemistry, and Climate Change:
An Integrated Modeling Study
Chien Wang
MIT
Linking Urban Pollution, Tropospheric
Chemistry and Climate Change
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Impact of urban air pollution on global tropospheric
chemistry and climate (e.g., tropospheric O3 and NOx
budgets, radiative forcing by O3 and aerosols);
Impact of future climate change on urban air pollution
and tropospheric chemistry (e.g., effects of clouds, UV,
precipitation, H2O, and temperature on reaction rates);
Interaction between urban/tropospheric chemistry and
climate under various emissions policies;
Anthropogenic aerosols' impact on human health;
Impact of air pollution and climate change on natural
ecosystems
Integrated Modelling Study
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Climate-chemistry interactions require models with integrated
components of atmosphere, ocean, tropospheric chemistry,
emissions (policy and non-policy), and ecosystem;
Integration time:  10 years for tropospheric chemistry studies
(primarily due to CH4 and O3 simulation as well as aerosol
forcing assessment),  100 years for tropospheric chemistry and
climate interaction studies;
Subgrid scale nature of urban and fast tropospheric chemistry as
well as lightning production of certain chemical species in
current global models with resolution coarser than ~100 km
requires adequate parameterizations for relevant processes;
Data base (measurement and emissions);
Computational efficiency (parallel, esp. distributed memory
computing)
MIT Interactive Chemistry-Climate Model
Atmospheric Chemistry Model
25 Chemical species
4 Aerosol groups
Advection, convection, and mixing
Gaseous and aqueous reactions
Wet and dry deposition
Concentrations
of chemicals
MIT 2DLO,
NCAR CCM/CSM, MIT AIM/OGCM
Urban Air Pollution Model
Natural Emission Model
Ocean Carbon Model
EPPA and Emission Preprocessor
Terrestrial Ecosystem Model
NPP, NEP, soil carbon pool
Climate Model
Circulation and state of atmosphere
Land and ocean
Clouds and Precipitation
Radiation
Winds, T, H2O,
precipitation
and radiative fluxes
Urban Air Pollution Model and Global Chemistry Model
Projected Future Increases of Emissions
(Emissions/Emissions of 1995; MIT EPPA)
4
SO2
Ratios
3.5
3
BC
2.5
OC
2
1.5
1
0.5
1995
2010
2025
2040
2055
Year
2070
2085
2100
Barrow (40W 70N)
Mauna Loa (155.4W 19.3N)
50.00
140.00
OBS 1992
Model
40.00
Surface BC in ng/M^3
Surface BC in ng/M^3
45.00
OBS 1989
Model
120.00
100.00
80.00
60.00
40.00
35.00
30.00
25.00
20.00
15.00
10.00
20.00
5.00
0.00
0.00
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov Dec
1
3
4
5
6
7
8
9
Month
Amsterdam Island (77.3E 37.5S)
South Pole (102W 87S)
10
11
12
3.50
14.00
OBS 1991
12.00
OBS 1989
Model
3.00
Model
10.00
Surface BC in ng/M^3
Surface BC in ng/M^3
2
Month
8.00
6.00
4.00
2.00
2.50
2.00
1.50
1.00
0.50
0.00
0.00
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug
Sep
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug
Sep
Oct
Nov
Dec
Summary
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Integrated models are needed for linking urban air pollution,
tropospheric chemistry, and climate; required integration time
varies from 10 - 100 years depending on the given topics;
Adequate parameterizations of urban scale air chemistry and
other subgrid scale chemical processes in global models are
critical to modeling results;
Future black carbon emissions may increase according to the
MIT EPPA Model;
Modeled radiative forcing of aerosols is highly uncertain,
multiple year integrations with uncertainty analyses are needed
for assessment;
Policy and health issues related to urban air pollution and
anthropogenic emissions of aerosols need to be explored and
inclusion of interaction between tropospheric chemistry and
climate change is important.