UC San Diego

Ocean mesoscale eddies, with 20 - 300 km size, present in energetic regions of the global ocean, are known to impact local and remote atmospheric weather. The impact of eddies in the Mediterranean Sea on the local weather, however, remains largely unknown. Here, we study this impact during an extreme weather event observed over Israel on January 8 - 10 , 2020, resulting in heavy rains and floods. To do so, we designed a set of coupled and forced numerical simulations with a horizontal resolution of 5 km in both ocean and atmosphere. The coupled simulation successfully reproduces the main characteristics of the torrential rains observed during the event, whereas the forced simulations exhibit poorer performance. Our results emphasize the importance of mesoscale air-sea coupling in supplying moisture to the atmosphere, via mechanisms involving both sea surface temperature and surface currents associated with sea eddies. Extreme weather events are intensified by the Mediterranean Sea eddies, especially through atmospheric meso-cyclones.