Global Upper Tropospheric/lower Stratospheric Water Vapor and Isotopologues from Satellites
Stiller, Gabriele P.1; Lossow, Stefan1; Kiefer, Michael1; Read, William G.2; Rosenlof, Karen H.3; Garcia-Comas, Maya4; Hervig, Mark. E.5; Nedoluha, Gerald6; Remsberg, Ellis. E.7; Russell III, James M.8; Thomason, Larry W.7; Urban, Joachim9; Walker, Kaley A.10; Weber, Mark. E.11; Weigel, Katja11; Zawodny, Joseph M.7
1Karlsruhe Institute of Technology, IMK-ASF, GERMANY; 2Jet Propulsion Laboratory, California Institute of Technology, UNITED STATES; 3ESRL Chemical Science Division, NOAA, UNITED STATES; 4Instituto de Astrofísica de Andalucía, CSIC, SPAIN; 5GATS Inc., Driggs, ID, UNITED STATES; 6Remote Sensing Physics Branch, NRL, UNITED STATES; 7NASA Langley Research Center, UNITED STATES; 8Atmospheric and Planetary Sciences Faculty, Hampton University, UNITED STATES; 9Department of Earth and Space Sciences, Chalmers University of Technology, Gothenburg, SWEDEN; 10Department of Physics, University of Toronto, CANADA; 11Institute for Environmental Physics, University of Bremen, GERMANY

The past decade has been a "golden age" for observations of middle atmospheric trace gas distributions from space since numerous satellite instruments have been in orbit. One of the most important trace species with respect to its impact on global climate and stratospheric chemistry is water vapor. The presentation will provide an overview on the currently available data base - including both the Envisat instruments and ESA Third Party Mission data - and on climatologies derived from the satellite data sets covering the altitude range from the upper troposphere to the lower mesosphere. The current and planned efforts within the SPARC Water Vapor Assessment II (WAVAS II) to intercompare the available satellite data sets and perform a quality assessment will be presented, with some focus on the difficulties which we are facing on the way to a consistent multi-instrument long-term data set covering the last 30 years. We will also discuss the distribution of water vapor isotopologues, mainly HDO, which can be derived from satellite data, and what can be learned from those about the transport of water vapor from the troposphere into the stratosphere, including phase transition processes (convective processes, freeze-drying, and overshooting of ice particles). Finally, future perspectives for the continuation of middle atmosphere water vapor observations from space will be discussed.