Analysis of A-Train Tropospheric NO2 and Aerosol Data

Pepijn Veefkind

OMI Tropospheric NO2 2005-2007Linear color scale from 0-1.3 1016 molecules/cm2

OMI Tropospheric NO2 2005-2007Linear color scale from 0-0.5 1016 molecules/cm2

Sources of NOx and Aerosol

Emission Source NOx Aerosol

Fossil Fuel Combustion x x

Biomass Burning x x

Desert Dust x

Sea Spray x

Lightning x

Biogenic x

Soils x

In Europe NOx is an important precursorfor ammonium nitrate particles

In Europe NOx is an important precursorfor ammonium nitrate particles

Total Emissions from of SOx and NOx in Europe for 1995

Data taken from Schaap et al.ACP 4, 857-874, 2004

OMI NO2 and MODIS AOT

Time period 2005-2007Gridded 1x1 degree

OMI Tropospheric NO2 MODIS AOT at 550 nm

West-EuropeEast EuropeMediterenean

Region Correlation Slope

West Europe 0.79 0.93 10-17

East Europe 0.58 1.68 10-17

Mediterenean -0.20 N/a

Total Emissions from of SOx and NOx in Europe for 1995

NOx SOx

Image from Schaap et al.ACP 4, 857-874, 2004In Eastern Europe more SOx is emitted per unit NOx,

leading to more aerosol mass per unit NOx and toa larger slope between the NO2 concentration and AOT

In Eastern Europe more SOx is emitted per unit NOx,leading to more aerosol mass per unit NOx and to

a larger slope between the NO2 concentration and AOT

Global Analysis

• OMI NO2 Domino Product monthly mean (regridded 1x1 degree)

• MODIS Aqua AOD at 550 nm monthly mean, (1x1 degree)

• Correlation calculated for 10x10 degree regions (max 100 points, at least 50 co-locations)

• Data is filtered for tropospheric NO2 larger than 5x1014 molec./cm2

• Data period 2005-2007

AOD

Trop. NO2

GOCART Model Data from the NASA GIOVANNI web site

Sulfate

Dust

Organic Carbon

MODIS Aqua

Correlation between NO2 and AOD

NW Europe E USA

Beijng E Coast Africa

Summary• High spatial resolution gridded data set of OMI

tropospheric NO2 data over Europe;

• Significant correlation between AOT and tropospheric NO2 is observed in both industrial and biomass burning regions.

• The slope between tropospheric NO2 and AOT is larger for East Europe as compared to West Europe, which may be explained by the difference of NOx and SO2 emissions;

• The combined analysis of AOD and tropospheric NO2

provide information on the aerosol sources.

Ground Based In-Situ Data

• LML Dutch air quality network, www.rivm.nl/lml• Regional, City and Street stations• Mean yearly value per station for 12:00 to 14:00 hrs

Comparison with the LML

Data from October 2004 to September 2005