HR: 0800h
AN: U21A-0807    [Abstracts]
TI: Towards Benchmark Climatologies of the Global Atmosphere With Radio Occultation Data From CHAMP
AU: * Foelsche, U
EM: ulrich.foelsche@uni-graz.at
AF: Wegener Center for Climate and Global Change (WegCenter) and Institute for Geophysics, Astrophysics, and Meteorology (IGAM), Univ. of Graz, Austria, Leechgasse 25, Graz, 8010 Austria
AU: Gobiet, A
EM: andreas.gobiet@uni-graz.at
AF: Wegener Center for Climate and Global Change (WegCenter) and Institute for Geophysics, Astrophysics, and Meteorology (IGAM), Univ. of Graz, Austria, Leechgasse 25, Graz, 8010 Austria
AU: Steiner, A K
EM: andi.steiner@uni-graz.at
AF: Wegener Center for Climate and Global Change (WegCenter) and Institute for Geophysics, Astrophysics, and Meteorology (IGAM), Univ. of Graz, Austria, Leechgasse 25, Graz, 8010 Austria
AU: Kirchengast, G
EM: gottfried.kirchengast@uni-graz.at
AF: Wegener Center for Climate and Global Change (WegCenter) and Institute for Geophysics, Astrophysics, and Meteorology (IGAM), Univ. of Graz, Austria, Leechgasse 25, Graz, 8010 Austria
AU: Borsche, M
EM: michael.borsche@uni-graz.at
AF: Wegener Center for Climate and Global Change (WegCenter) and Institute for Geophysics, Astrophysics, and Meteorology (IGAM), Univ. of Graz, Austria, Leechgasse 25, Graz, 8010 Austria
AU: Pirscher, B
EM: barbara.pirscher@stud.uni-graz.at
AF: Wegener Center for Climate and Global Change (WegCenter) and Institute for Geophysics, Astrophysics, and Meteorology (IGAM), Univ. of Graz, Austria, Leechgasse 25, Graz, 8010 Austria
AU: Lackner, B
EM: lackner@ifz.tu-graz.ac.at
AF: Wegener Center for Climate and Global Change (WegCenter) and Institute for Geophysics, Astrophysics, and Meteorology (IGAM), Univ. of Graz, Austria, Leechgasse 25, Graz, 8010 Austria
AU: Schmidt, T
EM: tschmidt@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Wickert, J
EM: jens.wickert@gfz-potsdam.de
AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AB: The radio occultation (RO) technique is based on a satellite-to-satellite limb sounding concept using microwave signals to probe the Earth's atmosphere. The propagation of Global Navigation Satellite System (GNSS) signals is influenced by the atmospheric refractivity field resulting in slowing and bending of the signal. The atmospheric phase delay as the principle observable is measured with millimetric accuracy. It is the basis for high-quality retrievals of atmospheric key variables, particularly of temperature profiles. Highest temperature accuracies of < 1 K are obtained in the upper troposphere and lower stratosphere. The high accuracy, long-term stability, self-calibrated nature, all-weather capability, high vertical resolution, and global coverage of RO data suggests them as a promising tool for global short- and long-term monitoring of atmospheric temperature change with benchmark quality. The German/US research satellite CHAMP (CHAllenging Minisatellite Payload for geoscientific research) continuously records RO profiles since March 2002. The mission is expected to last at least until 2007, thus CHAMP RO data provide the first opportunity to create real RO based climatologies on a longer term. We have developed a retrieval scheme which is tailored to minimizing biases, yielding a new atmospheric data set especially tuned for monitoring climate variability and change. The retrieved atmospheric profiles (150-160 profiles/day) are used to create climatologies on a monthly, seasonal, and annual basis by standard averaging-and-binning techniques. Here, we show temperature climatologies from the spring season (MAM) 2002 to the summer season (JJA) 2005, with special focus on potential sampling errors due to spatial and temporal undersampling of the true evolution of atmospheric fields and effects like drift in local time of the satellite orbit. Our results show that useful temperature climatologies resolving horizontal scales > 1000 km can be obtained even with data from a single RO receiver. RO based climatologies have the potential to improve modern operational climatologies, especially in regions where the data coverage and/or the vertical resolution and accuracy of RO data is superior to traditional data sources.
DE: 1610 Atmosphere (0315, 0325)
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1640 Remote sensing (1855)
SC: Union [U]
MN: Fall Meeting 2005