Extended Abstract (372K)P7.13
The effects of multilayer clouds on MODIS cloud effective radius and optical thickness retrievals
Shaima L. Nasiri, CIMSS/Univ. of Wisconsin, Madison, WI; and G. R. McGarragh
The focus of our study is the observation of multilayer clouds by satellites. Several multilayer cloud detection techniques have recently been proposed and developed. We demonstrate one such technique which identifies MODIS pixels that potentially contain thin cirrus overlying lower-level water clouds. Our approach is suitable for daytime imagery and uses the 1.63 µm or 2.13 µm band reflectance, and the 8.5 and 11 µm band brightness temperatures. We will present results that correlate occurrences of multilayer clouds with MODIS effective radius and optical thickness retrievals. Since the effective radius and optical thickness retrievals are made under the assumption of single layer clouds, we investigate the errors incurred by not accounting for multilayer clouds. We present results on several different spatial scales. First, we look at radiative transfer calculations to assess the maximum effect of multilayer clouds on an individual pixel. Next, we look at the retrievals within sub-granule sized scenes with a high percentage of multilayer clouds. We will also present imagery showing these effects on both regional and global MODIS data.
Poster Session 7, Retrievals and Cloud Products: Part 1
Thursday, 23 September 2004, 9:30 AM-11:00 AM
Previous paper Next paper