HR: 0800h
AN: A41A-0027    [Abstracts]
TI: Uncertainties of clear sky pixels in constructing surface reflectance for aerosol retrieval
AU: * Moon, K
EM: kjmoon3@freechal.com
AF: Global Environment Laboratory, Yonsei University, 134 Sinchon-dong, Seodaemoon-gu, Seoul, 120-749 Korea, Republic of
AU: Yoon, J M
EM: cromx2@yonsei.ac.kr
AF: Global Environment Laboratory, Yonsei University, 134 Sinchon-dong, Seodaemoon-gu, Seoul, 120-749 Korea, Republic of
AU: Kim, J
EM: jkim2@yonsei.ac.kr
AF: Global Environment Laboratory, Yonsei University, 134 Sinchon-dong, Seodaemoon-gu, Seoul, 120-749 Korea, Republic of
AU: Cho, H K
EM: hkcho@atmos.yonsei.ac.kr
AF: Global Environment Laboratory, Yonsei University, 134 Sinchon-dong, Seodaemoon-gu, Seoul, 120-749 Korea, Republic of
AB: The retrieval algorithms for the aerosol optical depth(AOD) from geostationary satellites usually assume clear sky pixel from the background composite which is constructed from the minimum visible reflectance during the previous 21 days to one month. The observed minimum reflectance are regarded as the aerosol free conditions for the pixel and are compared with the top-of-the-atmospehre reflectance from radiative transfer models with zero aerosol optical depth to retrieve surface reflectance. These surface reflectance affects the accuracy of AODs retrieved. Thus, in this study, using the ground-based measurements such as Rotating Shadowband Radiometer at Yonsei University, Seoul are analyzed to assess the uncertainties of the minimum reflectance composite in detail. From the time series of the ground-based dataset, minimum total optical depths(TOD) for the previous one months are obtained and compared with Rayleigh plus ozone optical depths. The result shows significant deviation from clear sky conditions especially in polluted areas from the minimum composite even during the previous 60 days.
DE: 0305 Aerosols and particles (0345, 4801)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting