HR: 0800h
AN: A51D-0823    [Abstracts]
TI: Current Status of the SAGE III Water Vapor Measurements: Algorithm Development and Preliminary Intercomparisons
AU: * Chiou, E
EM: e.chiou@larc.nasa.gov
AF: SAIC Corporation, One enterprise Pkwy, Suite 300, Hampton, VA 23666 United States
AU: Chu, W P
EM: w.p.chu@larc.nasa.gov
AF: NASA Langley Research Center, MS 475, NASA Langley, Hampton, VA 23681 United States
AU: Thomason, L W
EM: l.w.thomason@larc.nasa.gov
AF: NASA Langley Research Center, MS 475, NASA Langley, Hampton, VA 23681 United States
AB: The Stratospheric Aerosol and Gas Experiment III (SAGE III) is part of NASA's Earth Observing System (EOS) program. The SAGE III instrument, onboard the METEOR 3M-1, was successfully launched on December 10, 2001. Since then SAGE III data products of aerosol, ozone, nitrogen dioxide and cloud occurrence have been archived and released. Monitoring the stratospheric water vapor is also one of the major goals of SAGE III mission. Water vapor measurements from SAGE III are accomplished through the absorption signals observed with 29 channels from 930 nm to 960 nm wavelength region. The retrieval of water vapor profiles has been complicated by a number of factors including the etaloning effects due to attenuator plate and the spectroscopic uncertainty of the ozone cross sections in the corresponding wavelength region. In this presentation, a review of SAGE III water vapor retrieval algorithm will be given. Errors due to the contributions of interfering species will be discussed. Several modification schemes added to the pre-launched algorithm will be shown to demonstrate the efforts to account for the noises caused by the etaloning efftects. Preliminary results will be shown that compare SAGE III retrieved water vapor profiles with the coincident measurements from balloon-borne frost-point hygrometers and several satellite instruments (SAGE II, HALOE, and POAM-III). The agreement is generally within 10% to 12% with no systematic biases for altitudes below 27 km. Agreement diverges rapidly above this altitude, with SAGE III having systematic wet biases of the order of 1 ppmv (or approximately 20%).
DE: 3360 Remote sensing
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0694 Instrumentation and techniques
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting