Can we relate high resolution satellite-based aerosol optical depth (AOD) measurements to instantaneous evaporation rates in complex Dead Sea environs?

The Dead Sea, a hypersaline terminal lake at the lowest place on Earth, has undergone significant environmental changes in recent decades, most notably is the reduction to the lake.  In this work, we investigate the factors influencing evaporation in this rapidly changing hydrological system. We combine in-situ eddy-covariance evaporation measurements from Ein Gedi (2014-2017; DESERVE data) with Multi-Angle Implementation of Atmospheric Correction (MAIAC) aerosol optical depth (AOD satellite-based retrievals and local meteorology to quantify diurnal, seasonal, and aerosol-related variability. Despite an expected diurnal cycle, our analysis shows that in most months no statistically significant difference exists between morning (10:30 local time Terra overpass) and noon (13:30 for Aqua) evaporation, with January and March being the only exceptions (p < 0.01). Seasonal patterns are more pronounced, with maximum evaporation in spring and summer and minimum rates in winter. Our results identified several high-evaporation outlier clusters which coincided with extreme weather, particularly heavy rainfall events (e.g., January 2015; March 2014). These events occur during or immediately after synoptic disturbances, suggesting that non-typical meteorology can temporarily enhance evaporation via changes in salinity, vapor pressure deficit, and surface-atmosphere interactions. Analysis of the evaporation-AOD relationship shows a weak but statistically significant negative correlation in summer morning (Terra) measurements (r = 0.255, p = 0.0007), the season with the most stable atmospheric conditions. Multiple regression indicates that temperature is the dominant predictor of evaporation in all models, while wind speed, wind direction, and upwelling longwave radiation are significant only during morning overpasses. Notably, the region has complex pollution regimes, as is reflected by the relationship between both parameters, whereby a dust player can impact the interaction.  Meaning that dust events may suppress evaporation by reducing incoming solar radiation and altering the surface energy balance. These results provide the first quantitative evidence of aerosol-evaporation interactions at the Dead Sea using co-located in situ and satellite datasets.