HR: 14:40h
AN: A53D-04    [Abstracts]
TI: Comparison of Tropical GPS Radio Occultation Temperature and Water Vapor Retrievals with Ground-based Lidar and Radiosonde
AU: * Peng, G S
EM: grace.s.peng@aero.org
AF: Space Sciences Department, The Aerospace Corporation P.O. Box 92957 - M2/259, Los Angeles, CA 90009-2957 United States
AU: Farley, R W
EM: Robert.W.Farley@aero.org
AF: Photonics Technology Department, The Aerospace Corporation P.O. Box 92957 - M2/253 , Los Angeles, CA 90009-2957 United States
AU: Wessel, J E
EM: John.E.Wessel@aero.org
AF: Photonics Technology Department, The Aerospace Corporation P.O. Box 92957 - M2/253 , Los Angeles, CA 90009-2957 United States
AB: An intercomparison of temperature and water vapor soundings from CHAMP and SAC-C GPS radio occultations with coincident ground-based lidar measurements by the Aerospace Transportable Lidar System (ATLS) and ancillary radiosondes is presented. GPS occultations provide globally distributed high vertical resolution, horizontally averaged soundings of atmospheric refractivity. Stratospheric and upper tropospheric temperature and lower tropospheric water vapor can be obtained from refractivity. Imperfect ionospheric corrections and assumptions of mesosphere and upper stratosphere (~35-80 km) temperatures can result in unphysical oscillations in the upper regions of the GPS occultation temperature profile. Results from a recent January lidar campaign conducted in Hawaii during which lidar and GPS occultation detected significant medium to large-scale stratospheric wave activity are analyzed. An upper bound for physically significant temperature oscillations, atmospheric gravity waves, is deduced. Comparisons of water vapor are complicated by both its high temporal and spatial variability and the ambiguity in measuring water vapor and temperature with the GPS occultation method. However, we show that the vertical structure of water vapor in radiosonde, lidar and GPS occultation is in reasonable agreement.
DE: 3362 Stratosphere/troposphere interactions
DE: 3374 Tropical meteorology
DE: 3384 Waves and tides
DE: 3394 Instruments and techniques
DE: 0350 Pressure, density, and temperature
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting