Abstract
The ALARO-Climate regional climate model is based on the ALADIN cy36 numerical weather prediction model recently used for operational weather forecasting at the Czech Hydrometeorological Institute. The current model version includes improved prognostic schemes of cloud and precipitation microphysics and moist deep convection.
The schemes are designed to run the model at resolutions up to a very fine mesh-size where moist deep convection is partly resolved, but with a minimal overhead in the computational costs. In this paper, we present a validation of the ALARO-Climate experiment at 25 km horizontal resolution driven by ERA40 reanalysis for the period 1961-1990.
The analysed simulation serves as a basis for the forthcoming experiment with 6 km resolution. The model is capable of reliably simulating seasonal sea level pressure fields in Europe and the annual cycle of air temperature and precipitation in the Czech Republic.
However, precipitation amounts are overestimated in all months which are due to, among other reasons, a higher number of light precipitation days (up to 1 mm.day-1). Maximum and mean daily temperatures, and also daily temperature ranges, are generally lower in the model than observed.
The simultaneous underestimation of temperatures and overestimation of precipitation may partly be associated with the overestimated low cloud cover, appearing in spring, summer, and autumn. However, this cannot explain the same deficiencies in winter when the simulated cloud cover is in an agreement with the driving reanalysis.