P104   Sensitivity of Regional Climate Simulations for Europe to WRF Physics

Mooney, P.A., F.J. Mulligan, R. Fealy, National University of Ireland Maynooth, Ireland

The Advanced Research Weather Research and Forecasting (WRF) model is employed as a regional climate model for the European WCRP CORDEX Region 4 (http://copes.ipsl.jussieu.fr/SF_RCD_CORDEX.html) over the period 1989-1995.  ERA Interim reanalysis data is used to provide the initial conditions, lateral boundary information and SSTs at 6 hourly intervals in accordance with CORDEX hindcasting guidelines.  A grid spacing of 0.44¡×0.44¡ is used in order to economize on the computational effort involved over the relatively large domain.   

We present the results of 12 different physical parameterizations with a view to identifying the optimal choice of these parameters for climate modeling studies over Europe.  Two microphysics schemes, two longwave radiation schemes, two land surface models and two planetary boundary layer schemes have been investigated while the shortwave radiation, and cumulus physics schemes have been held fixed.  Modeled surface air temperature at 2 m and precipitation levels have been compared with EOBS observational data in their spatial distribution and temporal pattern.  To assist our investigation, the large domain has been subdivided into sub-regions that represent very different regional climates.  Bias analysis and probability density functions of the combinations of these physics schemes show that some regions in the domain are more sensitive to WRF physics than others.