Transcript Impact of Mexico City on Regional Air Quality

Impact of Mexico City on Regional Air Quality
Louisa Emmons
Jean-François Lamarque
NCAR/ACD
Chem-Climate WG White Paper
Hemispheric pollution to regional air quality: An issue of resolution
Louisa Emmons, Lyatt Jaegle, Loretta Mickley
Scientific advances to be accomplished within this project
1) Improved understanding of feedbacks between climate change and air pollution: effects
of changing temperatures/precipitation/water vapor on chemistry, effects of changing
emissions (biogenic NOx and VOC, lightning NOx, biomass burning, anthropogenic
emissions), effects of changing meteorology (synoptic and hemispheric scales,
stratosphere-troposphere exchange).
2) Improved understanding of feedbacks between climate change and export of pollution to
the global atmosphere: will a warmer climate lead to more efficient export of pollution?
How will it affect the long-range transport of pollution?
3) Improved understanding of the horizontal resolution needed to
accurately predict the influences of future climate change on regional air
quality and vice versa, through the use of the Weather Research and
Forecasting (WRF) model in conjunction with CAM.
4) Exploration of the possibility of downscaling global simulations for analysis of regional air
quality.
MILAGRO
March 2006
Comprehensive set
of measurements
from city to regional
scales
INTEX-B - NASA - DC-8 based in Houston
MIRAGE-Mex - NSF - C-130 based in Veracruz;
ground measurements
MAX-Mex - DOE - G1
MCMA - Molina Center - surface and mobile lab
Model Simulations
Meteorology: NCEP/GFS analyses (42 levels)
Emissions:
anthropogenic: POET-2000 and Mexico NEI (1999)
biomass burning: GFED-2 and C. Wiedinmyer’s N.America
calculations (MODIS daily fire counts)
MOZART-4
T42 (2.8°)
T85 (1.4°)
T170 (0.7°)
CAM-Chem
0.47°x0.63°
Model Evaluation
Comparison to C-130 measurements - all flights binned by altitude
Mexico
City
points
Finer resolution generally matches observations better
Model Evaluation
Acetone [ppbv]
CO [ppbv]
O3 [ppbv]
Comparison to surface measurements (T1)
Ozone from Mexico City - March 2006
NO emissions from Mexico City are
“tagged” to quantify O3
production
Average over March 2006, surface
to 400 hPa
T85 has higher concentrations over
Mexico City, but not larger
regional impact
NO emissions
POET emissions inventory
March 19 strong outflow event
2.8
°
1.4
°
T85 - higher O3 throughout
plume than T42
CAM-Chem - higher O3 over
city but weaker plume
C-130 data will be used to
evaluate
0.5
°
Radiative forcing of Mexico City emissions
Shortwave flux at the surface
24-hour average
W/m2
CAM-Chem, 0.47x0.63 resolution, driven by NCEP-GFS winds
CAM-Chem/DART in support of ARCTAS
Arctic Research of the Composition of the Troposphere from Aircraft
and Satellites (ARCTAS)
NASA aircraft campaign coincident with NOAA and DOE experiments
Part of POLARCAT/IPY
April - Fairbanks - Arctic haze, surface halogen chemistry
July - near Edmonton - Boreal wildfires
Chemical Forecasts
EnKF Data Assimilation: met
obs, MOPITT CO, MODIS
AOD
Then free-running forecasts
(5 days) for flight planning
Post-campaign Analysis
Evaluate and improve CAMChem
Interpret aircraft and satellite
observations