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Space-Based Constraints on NOx Emissions and Aerosol Single Scattering Albedo. Chris Sioris Kelly Chance. Randall Martin Aaron Van Donkelaar. Lyatt Jaegl é. Global Surface NO x Emissions Uncertain to Factor of 2 Implications for Tropospheric Ozone, Aerosols, and Indirect Effect. GEIA
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Space-Based Constraints on NOx Emissions and Aerosol Single Scattering Albedo Chris SiorisKelly Chance Randall Martin Aaron Van Donkelaar Lyatt Jaeglé
Global Surface NOx Emissions Uncertain to Factor of 2Implications for Tropospheric Ozone, Aerosols, and Indirect Effect GEIA Duncan et al. Yienger and Levy A priori Relative Uncertainty
SCIAMACHY/GOME Spectral Measurement Regions 30 km x 60 km 40 km x 320 km
Spectral Fit of NO2 Distinct NO2 Spectrum Solar Io Ozone Backscattered intensity IB NO2 Scattering by Earth surface and by atmosphere Albedo A O2-O2 Nonlinear least-squares fitting
Perform a Radiative Transfer Calculation to Account for Viewing Geometry and ScatteringCloud Screening: Remove Scenes with IB,c > 0.7*IB,o IB,c IB,o Io q • FRESCO Clouds Fields [Koelemeijer et al., 2002] • Surface Reflectivity [Koelemeijer et al., 2003] • LIDORT Radiative Transfer Model [Spurr et al., 2002] Rc Ro Pc dt Rs
Cloud-filtered Tropospheric NO2 Columns Observed from the SCIAMACHY Satellite Instrument (Data ICARTT) Lifetime ~ hours NO/NO2 W ALTITUDE May-Sept 2004 detection limit
Major Urban Centers Are Concentrated NOx Sources May-Sept 2004 detection limit
SPACE-BASED CONSTRAINTS ON NOx EMISSIONS Tropospheric NO2 Columns GOME GEOS-CHEM model (GEIA) JJA 1997 r = 0.75 bias=5% 1015 molecules cm-2 Martin et al. [2003] Error weighting A priori emissions (GEIA) A posteriori emissions Difference
43 Tg N May-Sept 2004 43 - 38 Tg N SCIAMACHY minus a priori
Satellite Observations of Soil NOx Emissions from Sahel40% of African NOx Emissions from Soils Results for the year 2000 Jaeglé, Martin, et al., JGR, 2004
Aerosol Single Scattering Albedo Major Source of Uncertainty in Global Radiative Forcing Estimates IPCC [2001]
Maximum Sensitivity to Aerosol Optical Thickness Over Dark SurfacesMore Sensitive to Single Scattering Albedo Over Bright Surfaces Staten Island Refinery Fire Saharan Dust Plume King et al., BAMS, 1999
TOMS Aerosol Index Measures Absorbing Aerosols In Ultraviolet Where Rayleigh Scattering Acts as Bright Surface July TOA spectral albedo measured by GOME
MODIS Optical Depth Includes Both Scattering and Absorbing Aerosols • Requires • aerosol size distribution information (AERONET and GEM-AQ) • Aerosol relative vertical distribution (LIDAR, GEM-AQ) • Use radiative transfer model to calculate SSA that reproduces observed Aerosol Index July 2000 MODIS AOD at 470 nm July 2000
Funding • Canadian Foundation for Climate and Atmospheric Sciences (CFCAS) • Natural Sciences and Engineering Research Council of Canada (NSERC) • National Aeronautics and Space Administration (NASA) • Canadian Foundation for Innovation (CFI) • Nova Scotia Research and Innovation Trust (NSRIT)