The contributions of the MAGIC project to the COST 716 objectives of assessing the operational potential of ground-based GPS meteorology on an international scale

MAGIC (Meteorological Applications of GPS Integrated Column Water Vapor Mea surements in the Western Mediterranean) is a 3 year project financed in par t by the European Commission for research on deriving and validating robust GPS integrated water vapor (IWV) and zenith tropospheric delay (ZTD) data sets and developing methods to assimilate the data into numerical weather p rediction models (NWP) and test their impact. It was conceived independentl y from the COST 716 action, which seeks to coordinate research in the domai n at an international scale, but addresses some of the same objectives. Thi s has led to a productive cooperation between the two initiatives and their participants, and motivated the decision of MAGIC participants to provide research results as part of the COST demonstration system. Currently a data base of 1.5 years of ZTD data are available on the MAGIC web site which has been validated through comparisons with radiosondes which gives difference s with a standard deviation of 10 mm ZTD or the equivalent error in IWV of 1.6 kg/m(2). NWP assimilation tests will be carried out in the final year o f the project. (C) 2001 Elsevier Science Ltd. All rights reserved.