Variability of the aridity in the South-Eastern Europe over 1961-2050

- The aridity will increase and shifts from one category to another may occur in the SEE.
- In the next decades, the temperature is increasing over the entire region.
- The precipitation will be higher in the northern part and lower in the south.

Past and projected variability of the air temperature, precipitation, evapotranspiration and aridity in the South-Eastern Europe are evaluated throughout 1961-2050. Changes in aridity are estimated by means of five indices: de Martonne Aridity Index, UNEP Aridity Index, Pinna Combinative Index, Johansson Continentality Index and Kerner Oceanity Index. The data were aggregated from three regional climate models (RCMs) - RegCM3, ALADIN-Climate and PROMES, at 25-km spatial resolution. Our study confirms that the South-Eastern Europe is warming, while the precipitation amounts are increasing in the northern part of the domain and decreasing in the southern areas. The potential and actual evapotranspiration perform accordingly, with obvious effects on aridity. The general aridity spatial pattern remains steady along 1961-2050, but significant shifts towards more arid categories will occur in the Pannonian Plain, in the proximity of the Black Sea, and in the eastern part of the Balkan Peninsula. Increases in both potential and actual evapotranspiration can be expected over the entire region, except for some coastal areas in southern Italy, Greece and Turkey, where the actual evapotranspiration may decrease, as a result of significantly less projected precipitation available for evaporation.