Precursors of Marine Heatwaves in the Eastern Mediterranean

Abstract Re‐analysis and observational data are used to identify the relationship between marine heatwaves and atmospheric heatwaves over the Eastern Mediterranean, and also the precursors of marine heatwaves in the 15‐day before heatwave onset. There has been a clear tendency for more heat extremes in recent years. Even though the specific dates in which marine heatwaves and atmospheric heatwaves occur do not match, most of the precursors are similar for both. These precursors include a weakened Indian monsoon, a strengthened Sahelian monsoon, a weakened Persian trough with a mid‐latitude low‐pressure system from the west, and an upper tropospheric ridge. The weakened Indian monsoon and Persian trough are evident at even earlier leads for marine heatwaves than for atmospheric heatwaves. Both latent heat and incoming shortwave radiation are highly anomalous in the lead‐up to marine heatwaves due to increased near‐surface atmospheric humidity, reduced wind speed, and reduced cloud cover.