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Very high resolution simulations

Very high resolution simulations
Ansprechpartner:
Dr. G. Schädler
N. Laube
B. Brecht
Projektgruppe:

IMK-TRO

Endtermin:

ongoing

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