Three-dimensional model simulations of CRISTA trace gas measurements

Abstract

Abstract The Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) experiment aboard the Shuttle Pallet Satellite (SPAS) was successfully flown on the Space Shuttle missions STS66 (November 94) and STS85 (August 97). During the first flight the atmosphere was found to be highly structured at horizontal scales less than 1000 km. Several streamers were found in various trace gas distributions. Trace gas distributions were modeled for the measurement period of the first flight (Nov. 4 to Nov. 12, 1994) by using a three-dimensional chemical transport model (CTM) of the middle atmosphere. The CTM is driven by wind and temperature data provided by the UK Meterological Office (UKMO). It uses the transport scheme and the chemistry code of the NCAR ROSE model (Research on Ozone in the Stratosphere and its Evolution). In this paper, modeled distributions of HNO 3 and CFC-11 are compared to respective CRISTA measurements. It is shown that the CTM captures the main structures of the measured trace gas distributions. The CTM has also been used for a data assimilation system. This system is briefly described and first results are presented.