Aerosol Information From High-Resolution Oxygen A-Band Measurements From Space
Geddes, Alexander; Boesch, Hartmut
University of Leicester, UNITED KINGDOM
Satellite instruments such as the Greenhouse gas Observing SATellite (GOSAT) measures shortwave infrared (SWIR) spectra with very high spectral resolution to retrieve greenhouse gas columns with high precision and accuracy. To mitigate path length variations related to scattering from aerosols and clouds, GOSAT also acquires spectra of the near-infrared oxygen A-band. Spectra of Oxygen absorption if measured with high signal-to-noise and spectral resolution can provide valuable information on optical depth as well as on the vertical distribution of aerosols which can otherwise only be obtained from active lidar measurements. Here we present a characterization of the expected information content and retrieval precision of aerosol parameters, such as optical depth or height and width of an aerosol layer, for a range of geophysical conditions including single and multiple aerosol layers and types for the simulated spectra of GOSAT and the forthcoming OCO-2, CarbonSat and Sentinel-5P missions. We also demonstrate the effects of unknown aerosol type and of non-aerosol parameters such as surface pressure, temperature and albedo on the aerosol retrieval.