| ABSTRACT | To assess the robustness of the COSMO-CLM regional climate model to simulate the precipitation and temperature distribution over Turkey, series of sensitivity experiments are conducted, and the comparisons of the sensitivity tests with the observations are presented. The climate mode of COSMO (COSMO-CLM) is used with spatial resolution of 0.11° (~10-12 km) and the model is integrated over 200x100 grid points domain over almost 5.5 year period between August 1st, 2007 and December 31th, 2012. The model is started end of summer when the soil moisture is near minimum over the most part of the domain. Therefore, only the first five months of model runs are considered as spin-up time and not included the analysis. The total of 212 observation stations common for both temperature and precipitation variables distributed approximately all over Turkey are used to investigate the model performance. The model simulation period includes two extreme years of 2008 and 2009 which represent dry and wet years, respectively. Although the temperature averages of dry and wet years are similar, the annual total precipitation averages of all 212 stations over Turkey are 430 mm for dry and 715 mm for wet years. In total, seven COSMO-CLM runs were performed with different options in terms of albedo, aerosol, vertical variation of critical humidity. Moreover, the performance of COSMO-CLM with two different spectral nudging is investigated. The effect of each sensitivity experiment on the precipitation and temperature simulations are evaluated over seven climatic zones of Turkey. |