Overview

Presently, most regional climate simulations are performed at horizontal resolutions around or coarser than 10 km. Higher resolution in the order of 1 km offers a series of advantages, including

• deep convection is simulated directly, therefore its parametrisation can be dispensed with
• the spatial and temporal variability and intermittency of quantities like temperature, precipitation and shortwave radiation is better accounted for, improving extreme value statistics
• small scale processes and phenomena which are persistent and therefore climatically relevant (e.g. small scale orographjy and land use variations, local/regional wind systems, shading, local precipitation nests) are accounted for in a more realistic way
• smaller bias in important variables, therefore less need for bias correction and therefore more consistent data
• smaller gap between resolution of the regional climate model output and resolution required by impact models

We performed a climate simulation at 0.025° (about 2.8 km) resolution, driven by ERA40 reanalyses, and covering the 30 a period 1971-2000 for Southern Germany. In the paper cited below, we present a comparison of these simulations with the regional climate model COSMO-CLM at a horizontal resolution of 2.8 km with observations and study the added value of such higher resolution compared to a coarser resolution of 7 km.

Presently, we do 0.025°-simulations driven by ECHAM6 data for a larger domain a recent past/future climate periods, and we intend to contribute to the CORDEX Flagship Pilot Study "Convective phenomena at high resolution over Europe and the Mediterranean".

Publications:

J. Hackenbruch, G. Schädler and J. W. Schipper (2016): Added value of high-resolution regional climate simulations for regional impact studies. Meteorologische Zeitschrift, Vol. 25, No. 3, 291–304