Remote sensing of the Dead Sea surface temperature

Abstract

The Dead Sea is a unique terminal lake located at the lowest place on Earth's surface. It has the highest surface temperature, salinity, and density among Earth's large water bodies, and its level is currently dropping at a rate of ∼1 m/a. Knowledge of the Dead Sea thermal and saline structure is based on meteorological and hydrological measurements from a single site at a time. In this study, we used satellite and in situ data to characterize the spatial and temporal variations of the Dead Sea sea surface temperature (SST) and to explore the causes for these variations. Sequences of almost continuous individual satellite images were transformed into a time series of parameters representing the spatial distribution of SST. Also used were in situ measured bulk SST, wind speed, solar radiation, and water temperature profiles with depth. Analysis of this data set shows strong diurnal and seasonal variations of the surface and vertical temperature field and the meteorological forcing. The temperature field is heterogeneous after noon, when radiation is high and wind speed is low and thermal layering develops. The temperature field is homogeneous during the nighttime, when solar radiation is absent and the high wind speed vertically mixes the upper layer.