A case study of very high resolution meteorological modelling in Alpine landscapes using MM5 and WRF

Numerical modelling in complex topographical areas is a challenge for mesoscale meteorological models and results are often not sufficiently realistic. To address this problem, making use of increasing computer capabilities, mesoscale models such as WRF and its predecessor MM5 are being pushed to higher horizontal and vertical resolutions in an attempt to better resolve the complex phenomena existing at this scale. Additional input data, such as higher resolved driving fields and static input fields (e.g. highly resolved DEM, snow cover maps) derived from satellite data, could help improving the results.

A case study is performed for two different mountainous stations, one located on the top of a mountain ridge (Schauinsland, Black Forest, Germany) and the other located on the bottom of an alpine valley (Innsbruck, Alps, Austria). High resolution meteorological numerical modelling for two selected episodes is carried out using two different mesoscale models, MM5 version 3.7 and WRF-ARW Version 3.2. SRTM3" data is used as elevation data. Evaluations of the influences of increasing horizontal (up to 200 m) and vertical (up to 80 sigma levels) resolutions in these complex topographical areas will be done. Comparison of the two models in simulating two different alpine landscapes and improvements of input files (e.g. DEM data) will be done.

Acknowledgements: This work is part of the HiRmod project, funded by the Austrian Climate and Energy Fund through the Austrian Climate Research Programme.