Exploitation of Ground Based GPS for Numerical Weather Prediction and Climate Applications in Europe

The operational potential of ground-based GPS data to the fields of climate and Numerical Weather Prediction (NWP) is demonstrated in the European COST-716 action. The best way hitherto for NWP is to assimilate Zenith Total Delay (ZTD), but in order to be useful the estimates must arrive within 1 hour and 45 minutes.To demonstrate this a trial was started in March 2001 involving several analysis centres, each processing a GPS network and delivering estimates of ZTD to a gateway at the UK Met Office in a standard meteorological data format. The network consists of 120 GPS stations in Europe, of which several are processed by more than one analysis centre. The algorithms, dataflow, formats and assimilation into Numerical Weather Prediction (NWP) models have been tested on 15 days of GPS data which were processed off-line, but to near-real time quality, for the period of June 9–23, 2000.In this paper we will focus on the achievements of COST-716, give an overview of the demonstration experiments and provide an outlook to future implementation of GPS data usage within operational meteorology and climate research.