J.Haase1, E. Calais2, J. Talaya3, A. Rius4, F. Vespe5, R. Santangelo6, X.-Y. Huang7, J. Davila8, M. Ge2, A. Flores4, H. Vedel7, K. Mogensen7, X. Yang7
1ACRI, BP. 234, F-06904 Sophia Antipolis, jh@acri.fr; 2CNRS, F-06560 Valbonne, 3ICC, E-08038 Barcelona, 4IEEC, E-08034 Barcelona, 5ASI, I-75100 Matera, 6OGMO, I-41100 Modena, 7DMI, DK-2100 Copenhagen, 8ROA, E-1110 Cadiz.
Since the use of Global Positioning System (GPS) receivers for measuring integrated water vapor (IWV) was first proposed, the coverage of GPS stations in Europe has been steadily increasing. As this potential observation network grows, so does its attraction to the meteorological community, but so also does the complexity of managing a disperse network of independently run stations. Compiling a data set from different processing centers for NWP model validation or assimilation tests requires validation of the consistency of the GPS processing methods and quality control of the output GPS IWV data. One objective of the MAGIC project (Meteorological Applications of GPS Integrated Column Water Vapor Measurements in the Western Mediterranean) is to demonstrate that this level of consistency can be achieved in direct response to the operational requirements of the meteorological community. The Danish Meteorological Institute (DMI) is the partner in the project charged with evaluating the impact of the GPS IWV data in the HIRLAM NWP model. DMI has given a target value of 0.5 cm in ZTD as an acceptable error level. In preliminary tests comparing the operational results of two of the processing centers (CNRS, IEEC), the difference between the ZTD has a standard deviation of 0.6 cm, which almost already satisfies the DMI requirement. Further results will be presented, as well as comparisons with the third processing center (ASI). A presentation of the overall objectives of testing the impact of GPS IWV data in NWP will also be provided.