randall martin aaron van donkelaar
DESCRIPTION
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 - PowerPoint PPT PresentationTRANSCRIPT
Randall MartinAaron Van Donkelaar
Chris Sioris Kelly Chance
Lyatt Jaeglé
Space-Based Constraints on NOx Emissions Space-Based Constraints on NOx Emissions and Aerosol Single Scattering Albedoand Aerosol Single Scattering Albedo
Global Surface NOGlobal Surface NOx x Emissions Uncertain to Factor of 2Emissions Uncertain to Factor of 2Implications for Tropospheric Ozone, Aerosols, and Indirect EffectImplications for Tropospheric Ozone, Aerosols, and Indirect Effect
Relative Uncertainty
GEIA
Duncan et al.
Yienger and Levy
A priori
SCIAMACHY/GOME Spectral Measurement RegionsSCIAMACHY/GOME Spectral Measurement Regions
40 km x 320 km 30 km x 60 km
Spectral Fit of NOSpectral Fit of NO22
Scattering by Earth surface and by atmosphere
Backscatteredintensity IB
Solar Io
Distinct NO2 Spectrum
RingeIAI s
B )()()( 0
Nonlinear least-squares fitting
Ozone
NO2
O2-O2
Albedo A
Perform a Radiative Transfer Calculation to Account for Viewing Perform a Radiative Transfer Calculation to Account for Viewing Geometry and ScatteringGeometry and Scattering
Cloud Screening: Remove Scenes with ICloud Screening: Remove Scenes with IB,c B,c > 0.7*I> 0.7*IB,oB,o
RcRo
IB,o IB,c
Pc
Rs
•FRESCO Clouds Fields [Koelemeijer et al., 2002]
•Surface Reflectivity [Koelemeijer et al., 2003]
•LIDORT Radiative Transfer Model [Spurr et al., 2002]
d
Io
Cloud-filtered Tropospheric NOCloud-filtered Tropospheric NO22 Columns Observed from the Columns Observed from the
SCIAMACHY Satellite Instrument SCIAMACHY Satellite Instrument (Data (Data ICARTT) ICARTT)
May-Sept 2004
detectionlimit
NO/NO2
W ALTITUDE
Lifetime ~ hours
Major Urban Centers Are Concentrated NOx SourcesMajor Urban Centers Are Concentrated NOx Sources
May-Sept 2004
detectionlimit
1015 molecules cm-2
r = 0.75 bias=5%
JJA 1997
SPACE-BASED CONSTRAINTS ON NOSPACE-BASED CONSTRAINTS ON NOx x EMISSIONSEMISSIONS
Tropospheric NO2 ColumnsGOME GEOS-CHEM model (GEIA)
Errorweighting
A priori emissions (GEIA) A posteriori emissions Difference
Martin et al. [2003]
May-Sept 2004
43 Tg N
43 - 38 Tg N
SCIAMACHY minus a priori
Satellite Observations of Soil NOx Emissions from SahelSatellite Observations of Soil NOx Emissions from Sahel40% of African NOx Emissions from Soils40% of African NOx Emissions from Soils
Jaeglé, Martin, et al., JGR, 2004
Results for the year 2000
Aerosol Single Scattering Albedo Major Source of Aerosol Single Scattering Albedo Major Source of Uncertainty in Global Radiative Forcing EstimatesUncertainty in Global Radiative Forcing Estimates
IPCC [2001]
Maximum Sensitivity to Aerosol Optical Thickness Over Dark SurfacesMaximum Sensitivity to Aerosol Optical Thickness Over Dark SurfacesMore Sensitive to Single Scattering Albedo Over Bright SurfacesMore Sensitive to Single Scattering Albedo Over Bright Surfaces
King et al., BAMS, 1999
Saharan Dust Plume Staten Island Refinery Fire
TOMS Aerosol Index Measures Absorbing Aerosols In Ultraviolet TOMS Aerosol Index Measures Absorbing Aerosols In Ultraviolet Where Rayleigh Scattering Acts as Bright SurfaceWhere Rayleigh Scattering Acts as Bright Surface
]})/[(log])/[({log100 3603311036033110 Rayleighmeas IIIIAI
July
300 400 500 600 700 800W avelength [nm ]
0.0
0.2
0.4
0.6
Ref
lect
ivity
TOA spectral albedo measured by GOME
MODIS Optical Depth Includes Both Scattering and MODIS Optical Depth Includes Both Scattering and Absorbing AerosolsAbsorbing Aerosols
MODIS AOD at 470 nm
July 2000
July 2000
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
FundingFunding
• 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)