Abstract
The assimilation of GPS radio occultations within the three-dimensional variational data assimilation system of the German Weather Service requires GPS radio occultation bending angle forward operators. To optimize the forward operator setup, different one- and three-dimensional bending angle forward operators are evaluated. The innovation statistics for radio occultation data from the CHAMP, GRACE-A, and FORMOSAT-3/COSMIC satellites are compared with estimates based on the background- and observation errors specified in the assimilation scheme. A numerical experiment is performed to assess the impact of assimilated radio occultation data on the weather forecast scores, to be compared to an experiment assimilating conventional observation data only.
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Acknowledgements
We thank the GeoForschungsZentrum (GFZ) Potsdam for reliably providing CHAMP and GRACE-A data sets of radio occultation data, both offline and near real time processed. The FORMOSAT-3/COSMIC project is gratefully mentioned for free provision of radio occultation data. We thank Michael Gorbunov for making the CT2 processing method and both bending angle forward operators available to us. The German Ministry for Education and Research supported the research project NRT-RO related to the near real time provision and usage of radio occultation data within the GEOTECHNOLOGIEN research program.
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Pingel, D., Rhodin, A. (2009). Assimilation of Radio Occultation Data in the Global Meteorological Model GME of the German Weather Service. In: Steiner, A., Pirscher, B., Foelsche, U., Kirchengast, G. (eds) New Horizons in Occultation Research. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-00321-9_10
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DOI: https://doi.org/10.1007/978-3-642-00321-9_10
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