HR: 10:35h
AN: A12A-02    [Abstracts]
TI: A Mass Balance for the Lowermost Stratosphere: Extratropical Versus Tropical Origin
AU: * Hoor, P M
EM: hoor@mpch-mainz.mpg.de
AF: Max-Planck-Institute for Chemistry, Dept.: Air Chemistry, P.O. Box 3060, Mainz, D-55020 Germany
AU: Gurk, C
EM: gurk@mpch-mainz.mpg.de
AF: Max-Planck-Institute for Chemistry, Dept.: Air Chemistry, P.O. Box 3060, Mainz, D-55020 Germany
AU: Fischer, H
EM: hofi@mpch-mainz.mpg.de
AF: Max-Planck-Institute for Chemistry, Dept.: Air Chemistry, P.O. Box 3060, Mainz, D-55020 Germany
AB: During the SPURT-project between 2001 and 2003 airborne in-situ measurements of trace gases in particular of CO, N2O and CO2 were performed in the tropopause region over Europe. A major objective was to get an overview on the distribution of these trace gases in the tropopause region to identify transport and mixing from the troposphere into the lowermost stratosphere and seasonal variations of the underlying processes. Mixing across the extratropical tropopause was found to affect mainly a layer which follows the local tropopause. This mixing layer exhibits the photochemical characteristic of both, the troposphere and the stratosphere. At large distances from the local tropopause the high precision measurements of CO2 with its well known tropospheric seasonal cycle facilitated to identify the tropical tropopause region as a source region for tropospheric air in the extratropical lowermost stratosphere, using the propagation of the CO2-seasonal cycle. The estimated transport times from the tropics are only on the order of weeks. On the basis of the in-situ measurements of CO we establish a mass balance for the lowermost stratosphere including transport from the extratropics as well as from the tropical tropopause region. We estimate that at large distances from the local tropopause the tropical tropospheric fraction dominates over tropospheric input from the extratropics, highlighting the importance of the tropical troposphere even for the lowermost stratosphere over Europe.
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3362 Stratosphere/troposphere interactions
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0341 Middle atmosphere--constituent transport and chemistry (3334)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting