Aerosol scavenging in continental outflow pathways

Constraints on Aerosol Scavenging in
Continental Outflow
Patrick Kim, Daniel Jacob, Helen Amos,
Jenny Fisher, Qiaoqiao Wang
Harvard University
GEOS-Chem Users’ Meeting
May 2, 2011
Modeling Long-range Aerosol Transport
Satellite Observations:
Aerosol Optical Depth (MODIS)
Carbon Monoxide (AIRS)
Aerosol Extinction (CALIOP)
What can we learn about aerosol export from satellite observations?
AOD:CO Correlations
Region of Interest
AOD:CO Correlations
Daily Collocated Aerosol and CO
April 2008
Satellite Observations
(MODIS, AIRS)
- Strong observed
correlations over
major sources
- GEOS-Chem
qualitatively
reproduces the
observed AOD:CO
relationships
Aerosol Optical Depth
GEOS-Chem
CO (molecules/cm2)
Surface AOD Measurements – AERONET
Station Locations
- FLAMBE improves model
comparison to AERONET
(Reduced mean bias and
improved correlation)
- Model performs poorly at sites
underestimating dust mixed
with pollution
Aerosol Vertical Profiles
Average Aerosol Vertical Profile (April 2008)
Altitude (km)
- Good model
agreement with
CALIOP in the
main transport
paths out of Asia
Model underestimate
associated with sources,
not scavenging
Aerosol extinction coefficient (km-1)
Aerosol Vertical Profiles
Altitude (km)
Average Aerosol Vertical Profile (April 2008)
Aerosol extinction coefficient (km-1)
Large changes in the aerosol vertical profile between the GEOS-5 and
MERRA met fields
Preliminary Conclusions & Future Work
- FLAMBE biomass burning emissions improve GEOS-Chem comparison
to AERONET relative to the GFED2 monthly product
- GEOS-Chem is capable of representing aerosol export out of Asia
but has trouble simulating Saharan dust events mixing with local
pollution
- There can be large differences in the simulated aerosol vertical
profile due to changes in both the scavenging parameterization
and the met fields themselves – this requires further investigation
Special Thanks to:
AIRS Science Team
CALIPSO Science Team
Tackett
MODIS Science Team
Juying Warner
Dave Winker, Mark Vaughan, Jason
Lorraine Remer, Shana Mattoo