Double tropopause characteristics from the full radio occultation record
Presenter:
Hallgeir Wilhelmsen
Wegener Center for Climate and Global Change, University of Graz, Graz, Austria, and FWF-DK Climate Change, University of Graz, Graz, Austria, and Institute for Geophysics, Astrophysics, and Meteorology/Institute of Physics (IGAM/IP), University of Graz, Graz, Austria.
Wegener Center for Climate and Global Change, University of Graz, Graz, Austria, and FWF-DK Climate Change, University of Graz, Graz, Austria, and Institute for Geophysics, Astrophysics, and Meteorology/Institute of Physics (IGAM/IP), University of Graz, Graz, Austria, and GeoForschungsZentrum Potsdam (GFZ), Potsdam, Germany.
Talk
The lapse rate tropopause definition from WMO (1957) enables us to detect double tropopauses from temperature profiles. Double tropopauses occur when the higher tropical tropopause domain overlap the lower mid-latitude tropopause domain. Double tropopauses have been associated with e.g. jet streams, Rossby wave breaking, poleward transport events, warm conveyor belts, or mountain gravity waves.
Due to the high accuracy in the tropopause altitude region and the high vertical resolution, radio occultation measurements are ideal to investigate the thermal tropopause. Also, the global coverage of the measurements facilitates studying double tropopauses globally.
In this work we present an analysis of double tropopauses using the full Wegener Center WEGC OPSv5.6 data record, from September 2001 to December 2018.
We also show a possible association between double tropoauses frequency and the El Niño Southern Oscillation.
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