DEVELOPMENT OF A HYDROLOGIC RUNOFF MODULE FOR A MESOSCALE ATMOSPHERIC MODEL

Wolfram Rühaak, Nicole Mölders
Institute for Meteorology - University Leipzig
wruehaak@curie.meteo.uni-leipzig.de/Fax: +49-341-97-32899

The efficiency of atmospheric models to describe the water cycle depends crucially on the integration of all partial cycles.
Therefore, the aim of this project is to develop a surface runoff and channel flow module on a subgrid scale, and to implement it into a mesoscale non-hydrostatic atmospheric model (the Leipzig version of GESIMA).
Overland and channel flow are modelled by a simplified form of the Barré de Saint-Venant equations linked with the Manning equation.
Due to the different characteristic sizes in meteorological vs. hydrological simulations the integration of the different spatial scaling and time steps is one of the most challenging parts.
Preliminary results of numerical studies will be presented and discussed.