Operation of two Doppler on Wheels (DOW) mobile X-band radars during COPS

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The Convective and Orographically-induced Precipitation Study (COPS) is an international field experiment scheduled to take place over moderate-mountain terrain in southwestern Germany and eastern France during June-August 2007, This proposal provides the scientific justification and experimental integration design for the deployment of two Doppler on Wheels (DOWs) mobile radars in the Black Forest region during COPS. The overarching COPS goal is to improve the skill of quantitative forecasts oforographically- induced convective precipitation. The terrain relief in the COPS region is -1000 m and it suffers from low forecast skill of quantitative precipitation and flash flooding potential. The DOW component of COPS aims to combine the DOW data with the multitude of European research and operational instruments to improve the basic understanding of the initiation and evolution of convection over moderate-mountain terrain. This improved understanding is expected to impact very short period forecasts of convective and precipitation processes. COPS research objectives directly complement research strategies developed in workshops sponsored by the U.S. Weather Research Program to improve Quantitative Precipitation Forecasts (QPFs; Fritsch and Carbone 2004; Dabberdt et al. 2005). COPS complements two recent field programs: the International H2O Project (IHOP_2002) and the Convective Storm Initiation Project (CSIP) in 2005. These three convection initiation and QPF field programs together cover broad flow regimes, varying topography, and extreme land-use variations. With different countries taking the lead on providing facilities, the programs are more cost effective than if the U.S. or E.U. attempted several programs aimed at different flow regimes over their regions. The mobility of the DOW radars will be a tremendous asset to COPS. This mobility enables them to be deployed in a variety of locations as meteorological conditions dictate. The DOWs will be strategically deployed in locations such that they can obtain dual- Doppler wind retrievals in regions not well observed by the German C-band operational and POLDIRAD research radars, such as in the lowest kilometer within the far reaches of the dual-Doppler lobes of those radars or within regions beyond the dual-Doppler lobes of these radars. Retrieval of the low-level kinematic fields is essential for understanding the boundary layer processes critical to convection initiation. COPS will be the first major international field campaign focused on the improvement of summertime convective QPF in a moderate-mountain region. It will constitute a major contribution to one of the most difficult and societally relevant research problems facing the atmospheric sciences community. Successful completion of the proposed research will improve the basic understanding of the initiation and evolution of convection over moderate-mountain terrain.