Climate change scenarios of convective and large-scale precipitation in the Czech Republic based on EURO-CORDEX data

摘要

There is growing evidence that the hydrological cycle is affected by climate change. Many studies have dealt with evaluation of precipitation characteristics in regional climate models (RCMs) and their projected changes. However, little attention has been given to possible differences between scenarios of convective and stratiform precipitation and changes in their proportions on total amounts, although climate models simulate convective (subgrid) and stratiform (large-scale) precipitation separately through deep (precipitating) convection and large-scale precipitation parameterizations. In this study, we analyse outputs of four RCMs (CCLM, HIRHAM, RACMO2, and RCA4) from the EURO-CORDEX project. The RCM simulations for 1989-2008 driven by ERA-Interim reanalysis with two horizontal resolutions (0.44 degrees and 0.11 degrees) are evaluated against observed data in Central Europe, and projected changes of precipitation characteristics (2071-2100 vs 1971-2000) simulated by the RCMs with 0.11 degrees horizontal resolution driven by the EC-EARTH global climate model are then examined. We find that mean convective and large-scale precipitation amounts tend to increase in all seasons except summer when large-scale precipitation amounts decrease. Extreme precipitation is projected to increase in the late 21st century time slice for both convective and large-scale precipitation. The changes of precipitation characteristics are more pronounced in simulations driven by the RCP8.5 scenario, with a larger increase of temperature, and these changes are larger for precipitation with higher intensity. Increasing proportion of convective precipitation in summer and generally increasing intensity of precipitation may have important consequences, e.g. for soil erosion, replenishment of soil moisture, and occurrence of flash floods and droughts.