| ABSTRACT | In this study, the effect of climate change on temperature extremes over Turkey is investigated in high resolution climate model simulations driven by a global model outputs. MPI-ESM2 earth system model simulations are downscaled to first 0.44o coarse resolution over Med-CORDEX domain and then 0.11o high resolution over the western part of Turkey by regional climate model, COSMO-CLM. The simulations cover the periods of 1970-2005 for the reference and 2005-2100 for the future with proposed changes under RCP 8.5. The simulations of CCLM for reference period, which have 0.44°resolution, are compared with average, maximum and minimum temperature values of CRU data. Both the model and CRU temperatures show decreasing trend from south to north between 1990-2005. The yearly temperature bias is ±2°C over Turkey. In addition to this, the consistency of CCLM decreases up to -3°C in the northeastern part of Turkey where locates high elevated mountains. When the seasonal averages are analyzed, it is seen that CCLM mimics the pattern of temperature distribution quite well. The largest cold bias is observed in summer season. The European countries that have negative bias in summer season experience generally positive bias in winter season. In order to compare 0.11° resolution model simulations, 78 Turkish State Meteorological Service observation stations for temperature are used. In winter and spring season, model produces warmer temperatures than observations especially over northern part of the domain. Summer has the coldest biases up to -6°C. Furthermore, climate projections between 2071 and 2090 show significant warming (>5°C) particularly over eastern and southeastern part of Turkey in summer. Extreme temperature climate indices such as FD0, SU25, TX10p, TN10p, TX90p, TN90p, TX35, WSDI, CSDI and DTR are calculated and compared to reference period. In addition, the climate indices are calculated for the intervals of 2015-2040,2041-2070,2071-2100, for RCP8.5 scenarios. FD0, TN10p, TX10p and CSDI indices decrease through the end of century and the most dramatic changes occur during summer season. On the other hand, the indices of SU25, TX90p, TN90p, TX35 and WSDI increase till 2100. Especially, the changes on the regions of southern Anatolia along the Aegean and Mediterranean Sea are large. |