Assessment of precipitation statistics with non-hydrostatic regional climate model RegCM4.7.1 at regional and convection-permitting scale over Bulgaria

The aim of this study is to present an assessment of precipitation, simulated with the non-hydrostatic regional climate model RegCM4.7.1 at a regional and convection-permitting (CP) scale for a decade-long period, over Bulgaria domain. The simulations use a horizontal grid spacing of 3 km and are driven by the ERA-Interim reanalysis (0.75° x 0.75°) through an intermediate driving RegCM4 simulation at 15 km grid spacing using parameterized deep convection. The km-scale simulation is evaluated against E-OBS (0.1° x 0.1°) and CHIRPS (0.05° x 0.05°) datasets and is compared with the coarser-resolution driving simulation. We focus on different precipitation statistics such as seasonal mean daily precipitation, seasonal wet-day intensity, seasonal wet-day frequency, and seasonal heavy precipitation. The simulated period is 2000 - 2010.  The simulations are carried out on the HPC Discoverer supercomputer, located in Sofia Tech Park in Sofia, Bulgaria. 

    Acknowledgements
    This work is supported by the Bulgarian National Science Fund, KP-06-М57/3. We acknowledge Discoverer PetaSC and EuroHPC JU for awarding this project access to Discoverer supercomputer resources.

   Keywords: RegCM4.7.1; km-scale resolution; convection-permitting; extreme precipitation; intensity; frequency; regional climate modelling; Bulgaria