HR: 0800h
AN: A21A-0714    [Abstracts]
TI: Tropical Cirrus Cloud Characteristics Using MODIS Level-3 Data
AU: Meyer, K
EM: kmeyer@ariel.met.tamu.edu
AF: Texas A&M University, Department of Atmospheric Sciences 3150 TAMU, College Station, TX 77843-3150 United States
AU: * Yang, P
EM: pyang@ariel.met.tamu.edu
AF: Texas A&M University, Department of Atmospheric Sciences 3150 TAMU, College Station, TX 77843-3150 United States
AU: Gao, B
EM: gao@nrl.navy.mil
AF: Naval Research Laboratory, Code 7230, Washington, DC 20375 United States
AU: Wiscombe, W
EM: warren.j.wiscombe@nasa.gov
AF: NASA Goddard Space Flight Center, Code 913, Greenbelt, MD 20771 United States
AB: The knowledge of the optical and microphysical properties of cirrus clouds is an important aspect of radiative and climate research. Cirrus clouds may substantially regulate the longwave energy balance near the tropical tropopause, yet the net effect of such clouds is not yet known. In fact, cirrus clouds have been identified as one of the most uncertain components in climate research. In this study, we detail a method for inferring tropical cirrus cloud optical thickness from MODIS level-3 derived cirrus reflectance and solar/satellite view geometry data. We then demonstrate the applicability of this method using independent MODIS level-3 data files from NASA's Aqua satellite to obtain the average daily tropical cirrus optical thickness. A preliminary study has also been conducted to ascertain the general characteristics of tropical cirrus cover using two years of Aqua MODIS data. This study includes the frequency of occurrence (number of days with cirrus optical thickness greater than zero), the spatial distribution of the optical thickness fields, as well as the latitudinal distribution of tropical cirrus clouds. The retrieval method described here is complimentary to the MODIS cloud retrieval product (included in level-3 data) for the case of tropical cirrus clouds.
DE: 8040 Remote sensing
DE: 4847 Optics
DE: 0360 Transmission and scattering of radiation
DE: 0669 Scattering and diffraction
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting