High-resolution projection of climate change and extremity over Israel using COSMO-CLM

Abstract

High-resolution climate projections over Israel (about 8 km) have been obtained with the regional model COSMO-CLM, nested into the CORDEX-MENA simulations at 25 km resolution. This simulation provides high-resolution spatial variability of total precipitation and precipitation intensity. Projections are presented not only in terms of average properties, but also using a subset of extreme temperature and precipitation indices from the standard Expert Team on Climate Change Detection and Indices (ETCCDI) for the period 2041–2070 with respect to 1981–2010 (RCP4.5).

A general increase in seasonal mean temperature is projected throughout the domain with peaks of ~2.5 °C, especially in winter and autumn. Extreme temperature indices show increases, larger in the minimum than in the maximum temperatures. Regarding total seasonal precipitation, decreases were found in the north and central Mediterranean climate parts of Israel, with reductions reaching ~40%, and increases of the same percentage in the most southern arid parts during winter and spring. An increase in precipitation intensity is shown mostly for the southern arid part of the region, with some indications of extremity also in the north. This spatial pattern probably results from a decrease in cyclones’ occurrences, which mainly influences the northern and central parts of Israel, and an increase in convective activity in the south.

The outcome of this study can serve as a basis for priority setting and policy formulation towards better climate adaptation.