1. Randall Martin Space-based Constraints on Emissions of Nitrogen Oxides With contributions from: Chris Sioris, Kelly Chance (Smithsonian Astrophysical Observatory) Lyatt Jaeglé (Univerisity of Washington) Yongtao Hu, Armistead Russell (Georgia Tech) Tom Ryerson (NOAA)

2. Relative Uncertainty Global Surface NO x Emissions Uncertain to Factor of 2 Implications for Tropospheric Ozone, Aerosols, and Indirect Effect Here in Tg N yr -1 (based on) Fossil Fuel 24 (GEIA) Biomass Burning 6 (Duncan et al., 2003) Soils 5 (Yienger and Levy, 1995) NOx Emissions (Tg N yr -1 ) Fossil Fuel (20-33) Biomass Burning (3-13) Soils (4-21)

3. Top-Down Information from the GOME and SCIAMACHY Satellite Instruments Nadir-viewing solar backscatter instruments including ultraviolet and visible wavelengths Low-elevation polar sun-synchronous orbit, late morning observation time GOME 1995-2002 Spatial resolution 320x40 km 2 Global coverage in 3 days SCIAMACHY 2002-present Spatial resolution 60x30 km 2 Global coverage in 6 days

4. Cloud-filtered Tropospheric NO 2 Columns Determined from SCIAMACHY May-Oct 2004 detection limit Retrieval based on Martin et al., 2002, 2003 Retrieval: Spectral fit Remove stratosphere Account for scattering

5. Use a CTM to Conduct a Chemical Inversion to Map NO x Emissions from Retrieved NO 2 Columns Emission NO NO 2 HNO 3 lifetime ~hours NITROGEN OXIDES (NO x ) BOUNDARY LAYER GOME SCIAMACHY NO / NO2   W ALTITUDE Tropospheric NO 2 column ~ E NOx

6. May-Oct 2004 48 Tg N yr -1 48 - 38 Tg N yr -1 Global Top-Down Emission Inventory Reveals Major Discrepancy in NOx Emissions from Megacities GEIA

7. ICARTT: COORDINATED ATMOSPHERIC CHEMISTRY CAMPAIGN OVER EASTERN NORTH AMERICA AND NORTH ATLANTIC IN SUMMER 2004 International, multi-agency collaboration targeted at regional air quality, pollution outflow, transatlantic transport, aerosol radiative forcing Terra ERS MISR, MODIS, MOPITT ERS-2 GOME Envisat SCIAMACHY Aqua AIRS, MODIS NASA DC-8 UK BAE-143 DLR Falcon NOAA-P3 Canada Convair NASA Proteus

8. North American NOx Emissions (May – October) Largest Change in Northeastern US Coast 10 11 atoms N cm -2 s -1 Bottom-up (NAPAP)Top-Down (SCIAMACHY) SCIAMACHY - NAPAP 7.6 Tg N 8.4 Tg N 0.8 Tg N r 2 = 0.85

9. Evaluate Top-Down and Bottom-Up NOx Inventories Conduct GEOS-CHEM Simulation For Each Inventory Sampled GEOS-CHEM Along Flight Tracks  NO x (ppbv) Simulation with SCIAMACHY – Original NOx Emission Inventory  HNO 3 (ppbv)

10. In Situ Airborne Measurements Support Top-Down Inventory In Situ GEOS-CHEM (Bottom-up) GEOS-CHEM (Top-Down) New EnglandNew England + GulfRemote P-3 Measurements from Tom Ryerson (NOAA)

11. Algorithm for partitioning top-down NO x inventory (2000) Algorithm tested using synthetic retrieval GOME NO x emissions Fuel Combustion 1. Spatial location of FF- dominated regions in a priori (>90%) 1 Biomass Burning 2. Spatiotemporal distribution of fires used to separate BB/soil VIRS/ATSR fire counts Soils No fires + background 2 Jaeglé et al., 2005

12. Soil emissions A posteriori 70% larger than a priori! A priori A posteriori Largest soil emissions: seasonally dry tropical + fertilized cropland ecosystems (±200%) (±90%) r 2 = 0.62 Soils Onset of rainy season: Pulsing of soil NO x ! North Eq. Africa Jaeglé et al., 2005 Soils East Asia

13. Error weighting EMIS: Emissions Mapping Integration Science Optimize North American NO x Emissions A posteriori emissions Top-Down Emissions May-Oct 2004 10 15 molecules cm -2 NOx Emissions (SMOKE/G.Tech) SCIAMACHY NO 2 Columns 10 11 molec N cm -2 s -1 Aug 2004