TARFOX Abstracts
at AGU Special Sessions
Baltimore, MD, 5/29-30, 1997

"Note that abstracts submitted to AGU electronically may also be located and viewed at the AGU website http://www.agu.org/meetings/waissm97.html."

Session A42D
Thursday 5/29, 1330-1635

"Retrieval of Aerosol Properties from the MODIS Airborne Simulator on the ER2 during the TARFOX experiment"

The idea is to use the measured radiance at the top of the atmosphere (TAO) in a wide spectral range (0.55-2.13 µm) to monitor the aerosol optical thickness (proportional to the aerosol total loading) and the aerosol size distribution (integrated on the vertical column) of the ambient (undisturbed) aerosol over ocean by comparing the radiance's with look-up table values. Even with the large spectral coverage provided by MODIS, there are not too many parameters that can be retrieved and pre-assumptions on the shape of the size distribution are required. Therefore, in the look-up table computations, the size distribution is described with two modes that are log-normals. The selected size distribution mergers that accumulation mode that is dominant by gas phase with that by cloud phase. It also mergers maritime particles with dust. We are so expecting to retrieve two 'free' parameters which are the ratio between the two modes and the optical thickness, as well as the mean particle size and the width of each mode, included in the table, which better fit the measurements. The algorithm has been successfully applied to actual data sets acquired during TARFOX and tested against ground and airborne measurements provided by the AErosol RObotic NETwork (AERONET), field network of sun-sky radiometers (Remer et al., 1997), and by the in-situ and radiometric measurements performed onboard the C-131A aircraft (Hobbs et al., 1997). A preliminary analysis shows that the derived optical thicknesses are in a good agreement with the airborne measurements acquired during clear and hazy conditions by the C-131 at the sea level. The retrieved size distributions compare also very well with the aerosol size distributions derived from the sun-sky measurements.

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Last updated Apr-30-1997

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