Alpine regional downscaling of reanalysis data using the LAM ALADIN

Principal Investigator

Dr. Alexander Beck
Department of Meteorology and Geophysics,
University of Vienna
Althanstrasse 12, UZA II
A-1090 Wien, Austria

alexander.beck@univie.ac.at

Project description

The performance of limited-area models (LAM) is crucially dependent on the quality of the coupling data from the host model. High-quality data of the atmospheric state is available from the reanalysis efforts carried out at major NWP centres. The local interpretation of these data sets as well as application within hydrological models requires spatial downscaling from almost 100km to a few kilometres. This scale gap is crucial for the regional interpretation of the data over complex terrain such as the European Alps.

Within this special project, the LAM ALADIN (see, e.g., Bubnova et al. 1995 and http://www.cnrm.meteo.fr/aladin/) shall be nested into reanalysis from the ECMWF ERA40 project as well as from the reanalysis of the 70-day Special Observing Period (SOP) of the Mesoscale Alpine Project (MAP; Bougeault et al. 2001) that has become available recently (Keil and Cardinali 2003). Emphasis will be given to the description of the hydrological cycle in Alpine areas as well as the quality of high-resolution precipitation forecasts. Moreover the quality of the selected Alpine watersheds. On the basis of the experiments carried out for the MAP SOP a limited set of downscaling experiments will be carried for selected decades within the ERA40 period to assess parameters relevant for regional climatologies.

Resources are requested mainly for accessing the MARS database and for carrying out the necessary post processing of the data for application within ALADIN. A limited set of IFS experiments is planned to provide coupling data for ALADIN on an hourly basis.

Bougeault, P., P. Binder, A. Buzzi, R. Houze, J. Kuettner, R.B. Smith, R. Steinacker, and H. Volkert, 2001: The MAP Special Observing Period. Bull. Amer. Soc ., 82, 433-462.

Keil , Ch. , and C. Cardinali, 2003: The ECMWF Re-Analysis of the Mesoscale Alpine Programme Special Observing Period. ECMWF Tech. Memo 401, 34pp.

Bubnova, R., G. Hello, P. Bernard, and J.F. Geleyn, 1995: Integration of the fully elastic equations cast in the hydrostatic pressure terrain-following coordinate in the framework of the ARPEGE/Aladin NWP system. Monthly Wea. Rev. , 123, 515-535.

For more details, please also refer to the latest Progress Report

Additional information

Project started in 2004.