Project: D-PHASE, Demonstration of Probabilistic Hydrological and Atmospheric Simulation of flood Events in the Alpine region - The Mesoscale Alpine Programme (MAP, the first WWRP Research and Development Project (RDP)) is an international research initiative devoted to the study of atmospheric and hydrological processes over mountainous terrain. It aims towards expanding our knowledge of weather and climate over complex topography, and thereby to improve current forecasting capabilities. A large-scale field phase in the Alpine region took place from 7 September to 15 November 1999. D-PHASE (Demonstration of Probabilistic Hydrological and Atmospheric Simulation of flood Events in the Alpine region) is a WWRP Forecast Demonstration Project (FDP) and aims at demonstrating some of the many achievements of MAP, in particular the ability of forecasting heavy precipitation and related flooding events in the Alpine region. The MAP FDP will address the entire forecasting chain ranging from limited-area ensemble forecasting, high-resolution atmospheric modelling(km-scale), hydrological modelling, and nowcasting to decision making by the end users, i.e., it is foreseen to set up an end-to-end forecasting system. The demonstration period of MAP D-PHASE will be 1 June to 30 November 2007. See also official homepage: http://www.map.meteoswiss.ch/map-doc/dphase/dphase_info.htm Please be aware of the common COPS/GOP/D-PHASE data policy, which you please find at http://cops.wdc-climate.de/ Summary: Accurate initialization of the water vapor field is important for NWP. With recent advances in Global Positioning System (GPS) atmospheric remote sensing, ground-based GPS receivers have become an important instrument that can provide high resolution water vapor measurements operationally at low cost with an accuracy of a few millimeters. The system can operate in all weather conditions. During the COPS campaign, a dense network of GPS receivers was installed. This data has been assimilated in real-time into the MM5 4DVAR system to improve quantitative precipitation forecasts and process understanding. Operational forecasts initialized with 4DVAR and corresponding CONTROL forecasts, initialized only by the ECMWF forecast,ran the whole COPS/D-PHASE period to provide a basis for future statistical investigations. This experiment contains only the innermost domain (2km) of the forecast initialized with the operational ECMWF forecast only (CONTROL). The corresponding 4DVAR forecast can be found as experiment dphase_mm5_2_4d. Assimilation run: - 18 km horizontal resolution - 36 level up tp 100 hPa - 64x70 grid points - MM5 3.4 (4DVAR version) - Kuo convection scheme - MRF PBL scheme - Simple radiation - Warm cloud microphysics - 3 hour assimilation window Free forecast run: only innermost 2km domain (CDOM) was archived) - Triple 2-way nested 24h forecast (18, 6, 2 km resolution) - 36 level up to 100 hPa - 64x70 points (18 km), 106x109 points (6 km), 169x184 points (2 km) - MM5 3.7.4 - Kain Fritsch 2 cumulus (no parameterization in the 2 km domain) - Reisner2 cloud microphysics - RRTM LW + Dudhia SW radiation - MRF PBL scheme - 5 layer soil model Note: here the datasets differ in time resolution (DDOM:1h, CDOM 15min) not in region. Grid description:"CDOM"+"DDOM":xinc/yinc:2.0 xnpole/ynpole:0.0 xfirst:6.0205 yfirst:47.0167 xsize:184.0 ysize:169.0