Kelly Chance Smithsonian Astrophysical Observatory INTERPRETING TROPOSPHERIC COMPOSITION FROM SATELLITE OBSERVATIONS OF SCATTERED RADIATION Randall Martin Kelly Chance Smithsonian Astrophysical Observatory Daniel Jacob Harvard University Dalhousie University

PRESENT AND FUTURE SATELLITE OBSERVATIONS OF TROPOSPHERIC CHEMISTRY Platform multiple ERS-2 Terra ENVISAT Space station Aura TBD Sensor TOMS AVHRR/SeaWIFS GOME MOPITT MODIS/MISR SCIAMACHY MIPAS SAGE-3 TES OMI MLS CALIPSO OCO Launch 1979 1995 1999 2002 2004 2005 O3 N N/L L CO CO2 NO NO2 HNO3 CH4 HCHO SO2 BrO HCN aerosol Increasing spatial resolution

TROPOSPHERIC OZONE COLUMNS (Sep’96-Aug’97) GEOS-CHEM TOMS (CCD) DJF MAM JJA SON R = 0.66 MODEL BIAS = -0.5 DU Martin et al., 2002a

OZONE ENHANCEMENT FROM LIGHTNING (GEOS-CHEM) largely explains observed wave-1 pattern in TOMS ozone Martin et al., 2002a

SCAN-ANGLE METHOD OBSERVES OZONE FROM BIOMASS BURNING OVER NORTHERN AFRICA DURING DJF Fire-counts Ozone in Dobson Units Kim et al., 2003

HOW DO WE EVALUATE AND IMPROVE BOTTOM-UP INVENTORIES? Surface NOX Global NOx Emissions (Tg N yr-1) Fossil Fuel (20-33) Biomass Burning (3-13) Soils (4-21) Here in Tg N yr-1 (based on) Fossil Fuel 24 (GEIA) Biomass Burning 6 (Logan/Duncan) Soils 5 (Yienger and Levy)

USE GOME MEASUREMENTS TO RETRIEVE NO2 COLUMNS TO MAP NOx EMISSIONS Retrieval Summary Spectral Fit (423-451 nm) GOME Total Slant Column Remove Stratosphere Tropospheric Slant Column Tropospheric NO2 column ~ ENOx Calculate AMF Tropospheric Column BOUNDARY LAYER Martin et al., 2002b NO2 NO/NO2   W ALTITUDE NO lifetime ~hours HNO3 Emission NITROGEN OXIDES (NOx)

VERTICAL COLUMNS CONFINED TO REGIONS OF SURFACE EMISSIONS Cloud/albedo artifacts removed by AMF calculation NO/NO2   WITH ALTITUDE NOx lifetime <1day Slant Vertical Martin et al., 2002b

GEOS-CHEM Tropospheric NO2 GOME Tropospheric NO2 GEOS-CHEM Tropospheric NO2 r=0.75 bias 5% Martin et al., 2003 1015 molecules cm-2

STRATEGY: OPTIMIZE SURFACE INVENTORY USING A PRIORI BOTTOM-UP AND GOME TOP-DOWN INFORMATION Top-down emissions A priori emissions A posteriori emissions A priori errors Top-down errors Martin et al., 2003

OPTIMIZED SURFACE NOX EMISSIONS 36.4 Tg N yr-1 37.7 Tg N yr-1 Martin et al., 2003

A POSTERIORI MINUS A PRIORI EMISSIONS Martin et al., 2003