Several reanalysis and model data sets, i.e., ERA-40, CRU and 20-km MRI-GCM, are employed to study the current and future changes in the wet season moisture fields over the Eastern Mediterranean (EM) including Turkey. The changes in moisture fields at the end of the present century, i.e. 2075--2099, are compared to the present period and discussed. It is shown that the very high-resolution 20 km GCM much better represents the current EM precipitation regime. Future projection of moisture fields suggests an increasing evaporation of about 12% and decreasing precipitation of about 7% over the EM at the end of this century. A significant decrease in precipitation was noticed over west Turkey, west Syria, Israel and Lebanon, with values of over 200 mm/wet season. In particular, the famous Fertile Crescent precipitation strip located over the ME also becomes much drier. The total moisture budget, usually expressed by the precipitation minus evaporation (P-E), confirms that a drier scenario is expected for the water body area and most of the coastline countries including southern Turkey. Analysis of the potential mechanism that controls the drying scenario shows that the precipitation recycling does not change between the present and the future. However, the moisture transport patterns over the EM explain the drying as follows. The subtropical mean flow of the low troposphere moves the moisture out of these regions, and there are not enough extra moisture sources to compensate in spite of the enhanced evaporation. One major conclusion is that the EM / ME topographic forcing including the physiographical changes effects are dominant. Therefore, high-resolution modelling plays a critical role in the atmospheric processes for this region.
|Title of host publication
|Climate Change Impacts on Basin Agro-ecosystems
|Tsugihiro Watanabe, Selim Kapur, Mehmet Aydin, Riza Kanber, Erhan Akça
|Place of Publication
|Cham: Springer International Publishing
|Number of pages
|Published - 2019