HR: 0800h
AN: A21E-0768    [Abstracts]
TI: Investigating In-cloud Relative Humidity and Thin Cirrus in the Upper Tropical Atmosphere Using AIRS, CALIPSO, and MLS
AU: * Liang, C K
EM: cliang@atmos.ucla.edu
AF: Joint Institute for Regional Earth System Science and Engineering, University of California, Los Angeles 9258 Boelter Hall Box 957228, Los Angeles, CA 90095-7228, United States
AU: Kahn, B H
EM: Brian.H.Kahn@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive Mail Stop 169-237, Pasadena, CA 91109, United States
AU: Eldering, A
EM: Annmarie.Eldering@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive Mail Stop 183-601, Pasadena, CA 91109, United States
AU: Fetzer, E J
EM: Eric.J.Fetzer@jpl.nasa.gov
AF: Jet Propulsion Laboratory, 4800 Oak Grove Drive Mail Stop 169-237, Pasadena, CA 91109, United States
AB: We investigate vertical and horizontal distributions of tropical oceanic thin cirrus optical and microphysical properties observed by the Atmospheric Infrared Sounder (AIRS). These properties are related to thermodynamic quantities, i.e., relative humidity with respect to ice (RHi), and cloud top temperature derived from the AIRS Level 2 operational soundings. Differences between all sky and in-cloud RHi are explored and possible mechanisms that explain these anomalies are discussed. Furthermore, we evaluate the hypothesis that many of the observed clouds are physically much thinner than the nominal resolution of AIRS, which may lead to dry biases of in-cloud RHi. To test this we exploit the co-located AIRS RHi and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) cloud thickness. Finally, we diagnose the ability of AIRS to measure water vapor in the Tropical Tropopause Layer (TTL) using co- located observations from the Microwave Limb Sounder (MLS). From this, a combined AIRS-MLS RHi product is used to investigate joint distributions of cirrus microphysical and optical properties, and RHi in the TTL.
DE: 3311 Clouds and aerosols
DE: 3360 Remote sensing
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting