Improving Calipso Lidar retrievals using MODIS TOA reflectances

1
Improving Calipso Lidar retrievals using MODIS
TOA reflectances

• Leona Charles, Barry Gross, Min Min Oo, Fred
  Moshary, Sam Ahmed
• Optical Remote Sensing Lab
• City College of New York

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Motivation

• Surface PM2.5 (aerosol mass) is crucial to air
  pollution monitoring and transport models
• Accurate surface level backscatter is a very
  strong predictor of PM2.5
• Calipso lidar measurements can in principal
  obtain surface level backscatter
• Unfortunately, lidar processing requires accurate
  knowledge of aerosol extinction/backscatter (S)
  ratios
• Present Calipso algorithms use global aerosol
  models with S ratio uncertainties estimated at
  30
• Therefore, we want to further constrain the
  possible atmospheres with MODIS TOA Reflectances
  in the VIS bands

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Backscatter Retrievals
Calipso Alone
Calipso MODIS Constraints
15
Range
Uncertainty Spreads of 15
Uncertainty Spreads of 30-40