Near East Desertification: impact of Dead Sea drying on the local conditions leading to convection 1,2 2 Samiro Khodayar and Johannes Hoerner 1Institute of Meteorology and Climate Research (IMK-TRO), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany 2Mediterranean Centre for Environmental Studies (CEAM), Valencia, Spain Submitted to Atmospheric Chemistry and Physics (HyMeX Inter-journal SI) * Corresponding author. E-mail address:
[email protected] (S. Khodayar) Mediterranean Centre for Environmental Studies (CEAM), Technological Park, Charles R. Darwin Street, 14 46980 - Paterna - Valencia - Spain 1 1 Abstract 2 The Dead Sea desertification-threatened region is affected by continual lake level 3 decline and occasional, but life-endangering flash-floods. Climate change has 4 aggravated such issues in the past decades. In this study, the impact of the Dead Sea 5 drying on the severe convection generating heavy precipitation in the region is 6 investigated. Sensitivity simulations with the high-resolution convection-permitting 7 regional climate model COSMO-CLM and several numerical weather prediction (NWP) 8 runs on an event time scale are performed over the Dead Sea area. A reference 9 simulation covering the 2003 to 2013 period and a twin sensitivity experiment, in which 10 the Dead Sea is dried out and set to bare soil, are compared. NWP simulations focus 11 on heavy precipitation events exhibiting relevant differences between the reference and 12 the sensitivity decadal realization to assess the impact on the underlying convection- 13 related processes. 14 The drying of the Dead Sea is seen to affect the atmospheric conditions leading to 15 convection in two ways: (a) the local decrease in evaporation reduces moisture 16 availability in the lower boundary layer locally and in the neighbouring, directly affecting 17 atmospheric stability.