engleski

Heavy precipitation events over Croatia during the HyMeX SOP1: Verifying the quantitative precipitation from a regional climate model CNRM - ALADIN52

Intense precipitation events and flash floods frequently affect the Mediterranean region, thereby posing a threat to people and property. A considerable number of heavy precipitation events (HPEs) hit the eastern Adriatic during the first HyMeX Special Observation Period (SOP1), 5 September to 6 November 2012. The aim of our study is to evaluate the regional climate model's (RCM's) skill to reproduce HPEs and to verify the quantitative precipitation forecast (QPF) by using SAL. A three-dimensional quality measure SAL is object-based and takes into account the structure (S), the amplitude (A) and the location (L) of the precipitation field. Here, SAL was computed from daily precipitation simulated by ALADIN-Climate model version 5.2 (CNRM-ALADIN52) driven by ERA-Interim reanalysis over the Med- CORDEX domain, and observational datasets: E-OBS (high-resolution land-only gridded observational dataset over Europe) and TRMM (satellite-derived precipitation). Additionally, we compared the results of CNRM-ALADIN52 driven only at its lateral boundaries to the one where spectral nudging method was applied. For the largest number of intensive observation periods (IOPs) SAL values show that the CNRM-ALADIN52 underestimates precipitation amounts with too small and/or too peaked objects, while the opposite holds in a smaller number of events. The CNRM-ALADIN52 compared to E-OBS gives less dispersed S and A values and better L values, than when compared to TRMM. Also, precipitation fields from the nudged CNRM-ALADIN52 simulation tend to group SAL values around the perfect QPF (i.e., S=0, A=0, L=0) outperforming CNRM-ALADIN52 simulation without nudging. Overall, CNRM ALADIN52 is rather successful in reproducing the timing and spatial variability of HPEs ; however in most cases it is unable to reproduce the exact precipitation amount, especially when extremely heavy rainfall occurred.

regional climate model, ALADIN-Climate, heavy precipitation event, SAL, quantitative precipitation forecast

nije evidentirano