Projected changes in mean and extreme precipitation over the Mediterranean region from a high resolution double nested RCM simulation

Abstract

Results are presented from high resolution climate change simulations over the Mediterranean region using the ICTP Regional Climate Model, RegCM3. Two sets of multi‐decadal simulations are performed at 20‐km grid spacing for present day and future climate (IPCC A2 scenario). We analyze changes in precipitation mean and extremes and find that the change signal shows seasonally dependent fine scale structure in response to the topographic forcing and changes in circulation, especially over the Alpine region and the Iberian, Italian and Hellenic peninsulas. In winter, the mean precipitation change is positive in the Northern Mediterranean regions and negative in the Southern Mediterranean, while precipitation in the other seasons mostly decreases (especially in summer), except over some localized areas. Changes in extreme precipitation events and dry spells suggest not only shifts, but also a broadening, of the precipitation distribution, with an increased probability of occurrence of events conducive to both floods and droughts.