HR: 0800h
AN: A41B-0435    [Abstracts]
TI: Retrieval of Aerosol Optical Thickness and Normalized Water-Leaving Radiances From the SeaWiFS and MODIS Sensors Over the Chesapeake Bay Area (Case 2 Water)
AU: * Ahmad, Z
EM: Ziauddin.Ahmad-1@nasa.gov
AF: Science and Data Systems,Inc., 16509 Copperstrip Lane, Silver Spring, MD 20906, United States
AU: Kwiatkowska, E J
EM: Ewa.Kwiatkowska@nasa.gov
AF: Science Applications International Corporation, 10260 Campus Point Drive, San Diego, CA 92121, United States
AU: Franz, B A
EM: Brayn.A.Franz@nasa.gov
AF: Science Applications International Corporation, 10260 Campus Point Drive, San Diego, CA 92121, United States
AU: McClain, C R
EM: Charles.R.McClain@nasa.gov
AF: NASA Goddard Space Flight Center, Greenbelt Road, Greenbelt, MD 20771, United States
AB: Presently, a suite of 12 aerosol models are used for atmospheric correction purposes to retrieve normalized water-leaving radiances in the visible bands of the SeaWiFS and MODIS sensors. These aerosol models are based on Shettle and Fenn's models (1979) of tropospheric and oceanic aerosols. Over most of the open oceans of the world (case 1 water), the atmospheric correction algorithm has been shown to work reasonably well. However, over case 2 waters, (for example Chesapeake Bay) the algorithm often yields negative water- leaving radiances, particularly, in the blue bands of the two sensors. In addition, over the coastal areas, the retrieved aerosol optical thickness (AOT) in the 865/869 bands are often higher than the in situ AERONET retrievals. Our analysis of the AERONET data show that Shettle and Fenn's aerosol models are not representative of the aerosols generally found over the coastal region of the Eastern United States. We show that use of wrong aerosol models often results in negative water-leaving radiances. Also, the backscattering of the solar irradiance in the near IR bands by phytoplankton and non-algal suspended particles results in overestimation of AOT. Based on the AERONET data, we have developed a set of new aerosol models for the atmospheric correction over Chesapeake Bay. Results from the new aerosol models, including comparison of satellite-derived AOT and the AERONET in the visible and near IR bands, will be presented.
DE: 0480 Remote sensing
DE: 3360 Remote sensing
DE: 4801 Aerosols (0305, 4906)
DE: 4906 Aerosols (0305, 4801)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting