HR: 1340h
AN: A13A-0887    [Abstracts]
TI: Evidence for mid and High-Latitude Cirrus Cloud Well Above the Tropopause Caused by Isentropic Transport of Tropical Water Vapour
AU: Spang, R
EM: r.spang@fz-juelich.de
AF: Research Center Jülich, Institute for Chemistry and Dynamics of the Geosphere, ICG I, Staatsforst Stetternich, Juelich, 52425 Germany
AU: Riese, M
EM: m.riese@fz-juelich.de
AF: Research Center Jülich, Institute for Chemistry and Dynamics of the Geosphere, ICG I, Staatsforst Stetternich, Juelich, 52425 Germany
AU: * Grooss, J
EM: j.-u.groos@fz-juelich.de
AF: Research Center Jülich, Institute for Chemistry and Dynamics of the Geosphere, ICG I, Staatsforst Stetternich, Juelich, 52425 Germany
AU: Gunther, G
EM: g.guenther@fz-juelich.de
AF: Research Center Jülich, Institute for Chemistry and Dynamics of the Geosphere, ICG I, Staatsforst Stetternich, Juelich, 52425 Germany
AU: Trieu, B
EM: b.trieu@fz-jeulich.de
AF: University of Wuppertal, Department of Physics, Gass Str. 20, Wuppertal, 42119 Germany
AB: Despite the great importance of several trace constituents (especially water vapour and clouds) in the UT/LS region for the climate system, the distribution of these quantities is far from being well understood. This is a result of the existing lack of global observations with sufficiently high vertical and horizontal resolution. The Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) instrument made a number of snapshots of the UT/LS during its two Space Shuttle missions and demonstrated the potential of the IR limb viewing technique to provide information on several trace constituents and subvisible cirrus clouds (SVC) with comparably high spatial resolution. The presentation gives an overview of CRISTA-2 water vapour and cirrus observations (August 1997) in the UT/LS in comparison with corresponding ECMWF data and simulations by the chemical transport model CLaMS (Chemical Lagrangian Model of the Stratosphere). The observations suggest considerable flux of moisture from the tropical troposphere into the extra-tropical lowermost stratosphere, accompanied by high cirrus cloud occurrence frequencies even at rather high northern latitudes (65 deg N at 350 K surface). The observations are well captured by CLaMS simulations, which highlight the connection between isentropic quasi-horizontally transport of water vapour from the tropics and the occurrence of cirrus clouds in the lowermost stratosphere well above the tropopause.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0320 Cloud physics and chemistry
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005