Special Issue on Multi-Angle Measurements and Models.pdf

Aerosol Properties Derived from Aircraft Multi-angle Imaging Over Monterey Bay Ralph Kahn, Pranab Banerjee, Duncan McDonald Jet Propulsion Laboratory,California Institute of Technology 4800 Oak Grove Drive, Pasadena CA 91 109 \ For: The JournalGeophysicalof Research, Atmospheres Special Issue on Multi-Angle Measurements and Models March, 2000 1 Abstract ThefirstgenericandclimatologicalaerosolretrievalsusingAirMISRdataare presented. Observations in a cloud-free region over MontereyBayonJuly 29, 1999, yieldcomplementary generic and climatological results. According to the generic retrieval, the cross-section-weighted, column-mean aerosol properties are: 2, = 0.1 -I: 0.05, with a preference for values on the low side of the range, ra = 0.45 0.15, with a preference for the 0.30 to 0.40 sub-range, ni 0.003, with 0.0 as the most likely value. These properties correspondingto a large spherical column-average particle, such assea salt. The climatologicalretrieval identifies a Maritime airmass, having a total aerosol opticaldepth about 0.1, and fractional optical depths for sea salt of 50% in MISR Band 2, and 40% for the sulfate + carbonaceous (medium, spherical) components, to an accuracy of about k 15%.These results, in good agreementwithnearby surface-based andaircraft observations, represent an early step toward the goal of adding spatial detail and information about temporal variability to the global aerosolclimatologywith MISR multi-angle data. 1. Introduction The Multi-angle Imaging SptectroRadiometer (MIS