Spatial Non-Uniformity of Surface Temperature of the Dead Sea and Adjacent Land Areas

Pavel Kishcha,Pinhas Alpert,Boris Starobinets,Pavel Kunin,Rachel T Pinker

doi:10.3390/rs12010107

Abstract

Pronounced spatial non-uniformity has been obtained of daytime sea surface temperature (SST) of the Dead Sea and of land surface temperature (LST) over areas adjacent to the Dead Sea. This non-uniformity was observed in the summer months, under uniform solar radiation. Our findings are based on Moderate Resolution Imaging Spectroradiometer (MODIS) data (2002–2016) on board the Terra and Aqua satellites. MODIS data showed that, on average for the 15-year study period, daytime SST over the eastern part of the lake (Te) exceeded by 5 °C that over the western part (Tw). This SST non-uniformity (observed in the absence of surface heat flow from land to sea at the eastern side) was accompanied by spatial non-uniform distribution of land surface temperature (LST) over areas adjacent to the Dead Sea. Specifically, LST over areas adjacent to the eastern side exceeded by 10 °C that over areas adjacent to the western side. Our findings of spatial non-uniformity of SST/LST based on MODIS data were supported by Meteosat Second Generation LST records. Regional atmospheric warming led to a decrease in spatial non-uniformity of SST during the study period. Temperature difference between Te and Tw steadily decreased at the rate of 0.32 °C decade−1, based on MODIS/Terra data, and 0.54 °C decade−1, based on MODIS/Aqua data. Our simulations of monthly skin temperature distribution over the Dead Sea by the Weather Forecast and Research (WRF) model contradict satellite observations. The application to modeling of the observed SST/LST spatial non-uniformity will advance our knowledge of atmospheric dynamics over hypersaline lakes.

Highlights

The Dead Sea is a terminal hypersaline lake with a depth of ~300 m, at a unique location approximately 430 m below sea level
These months were chosen for the following reasons: (1) precipitation does not occur, and (2) cloud cover over the Dead Sea is insignificant and does not influence solar radiationFigure 2a,b represent two maps: one (Figure 2a) is the 15-year mean spatial distribution of daytime sea surface temperature (SST) at 10:30 LT based on Moderate Resolution Imaging Spectroradiometer (MODIS)/Terra data, and the second (Figure 2b) is the 15-year mean spatial distribution of daytime SST at 13:30 LT based on MODIS-Aqua data
Pronounced spatial non-uniformity has been obtained of daytime sea surface temperature (SST) of the Dead Sea, and of land surface temperature (LST) over areas adjacent to the Dead Sea

Summary

Introduction

The Dead Sea is a terminal hypersaline lake with a depth of ~300 m, at a unique location approximately 430 m below sea level. Because of high salinity of ~300 PSU of Dead Sea water [1], the non-linear absorption of solar radiation is greater than that in fresh-water lakes such as the Sea of Galilee, located in the same climatic zone. In the absence of vertical water mixing under weak winds, solar radiation leads to significant warming of Dead Sea surface water. This warming of Dead Sea surface water could be non-uniformly distributed because of a possible inhomogeneous distribution of surface winds in the daytime. Further investigation of spatial non-uniformity of SST will advance the general understanding of SST-related atmospheric processes over the Dead Sea and over other hypersaline lakes

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Discussion

Conclusion