scholarly journals Observations of positive sea surface temperature trends in the steadily shrinking Dead Sea

2018 ◽  
Vol 18 (11) ◽  
pp. 3007-3018 ◽  
Author(s):  
Pavel Kishcha ◽  
Rachel T. Pinker ◽  
Isaac Gertman ◽  
Boris Starobinets ◽  
Pinhas Alpert
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Feedback Loop ◽  
Sea Water ◽  
Dead Sea ◽  
Sea Surface ◽  
Positive Feedback Loop ◽  
Temperature Trends ◽  
The Dead

Abstract. Increasing warming of steadily shrinking Dead Sea surface water compensates for surface water cooling (due to increasing evaporation) and even causes observed positive Dead Sea sea surface temperature trends. This warming is caused by two factors: increasing daytime heat flow from land to sea (as a result of the steady shrinking) and regional atmospheric warming. Using observations from the Moderate Resolution Imaging Spectroradiometer (MODIS), positive trends were detected in both daytime and nighttime Dead Sea sea surface temperature (SST) over the period of 2000–2016. These positive SST trends were observed in the absence of positive trends in surface solar radiation, measured by the Dead Sea buoy pyranometer. We also show that long-term changes in water mixing in the uppermost layer of the Dead Sea under strong winds could not explain the observed SST trends. There is a positive feedback loop between the positive SST trends and the steady shrinking of the Dead Sea, which contributes to the accelerating decrease in Dead Sea water levels during the period under study. Satellite-based SST measurements showed that maximal SST trends of over 0.8 ∘C decade−1 were observed over the northwestern and southern sides of the Dead Sea, where shrinking of the Dead Sea water area was pronounced. No noticeable SST trends were observed over the eastern side of the lake, where shrinking of the Dead Sea water area was insignificant. This finding demonstrates correspondence between the positive SST trends and the shrinking of the Dead Sea indicating a causal link between them. There are two opposite processes taking place in the Dead Sea: sea surface warming and cooling. On the one hand, the positive feedback loop leading to sea surface warming every year accompanied by long-term increase in SST; on the other hand, the measured acceleration of the Dead Sea water-level drop suggests a long-term increase in Dead Sea evaporation accompanied by a long-term decrease in SST. During the period under investigation, the total result of these two opposite processes is the statistically significant positive sea surface temperature trends in both daytime (0.6 ∘C decade−1) and nighttime (0.4 ∘C decade−1), observed by the MODIS instrument. Our findings of the existence of a positive feedback loop between the positive SST trends and the shrinking of the Dead Sea imply the following significant point: any meteorological, hydrological or geophysical process causing the steady shrinking of the Dead Sea will contribute to positive trends in SST. Our results shed light on continuing hazards to the Dead Sea.

scholarly journals Observations of positive sea surface temperature trends in the steadily shrinking Dead Sea

2018 ◽  
Author(s):  
Pavel Kishcha ◽  
Rachel T. Pinker ◽  
Isaac Gertman ◽  
Boris Starobinets ◽  
Pinhas Alpert
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Water ◽  
Dead Sea ◽  
Water Levels ◽  
Sea Surface ◽  
Surface Warming ◽  
Temperature Trends ◽  
The Dead

Abstract. The steadily shrinking Dead Sea followed by sea surface warming compensates surface water cooling due to increasing evaporation, and even causes the observed positive Dead Sea surface temperature trends. Using observations from Moderate Resolution Imaging Spectroradiometer (MODIS), positive trends were detected in both daytime (0.06 °C year−1) and nighttime (0.04 °C year−1) Dead Sea surface temperature (SST) over the period of 2000–2016. These positive SST trends were observed in the absence of positive trends in surface solar radiation measured by the Dead Sea buoy pyranometer. Neither changes in water mixing in the Dead Sea nor changes in evaporation could explain surface temperature trends. There is a positive feedback loop between the shrinking of the Dead Sea and positive SST trends, which leads to the accelerating decrease in Dead Sea water levels during the period under study. Note that there are two opposite processes based on available measurements: on the one hand, the measured accelerating rate of Dead Sea water levels suggests a long-term increase in Dead Sea evaporation which is expected to be accompanied by a long-term decrease in sea surface temperature. On the other hand, the positive feedback loop leads to the observed shrinking of the Dead Sea area followed by sea surface warming year on year. The total result of these two opposite processes is the statistically significant positive sea surface temperature trends in both daytime (0.06 °C year−1) and nighttime (0.04 °C year−1) during the period under investigation, observed by the MODIS instrument. Our results shed light on the continuing hazard to the Dead Sea and possible disappearance of this unique site.

scholarly journals Remote sensing of the Dead Sea surface temperature

2009 ◽  
Vol 114 (C5) ◽  
Author(s):  
R. Nehorai ◽  
I. M. Lensky ◽  
N. G. Lensky ◽  
S. Shiff
Keyword(s):  
Remote Sensing ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Dead Sea ◽  
Sea Surface ◽  
The Dead

scholarly journals Spatial Heterogeneity in Dead Sea Surface Temperature Associated with Inhomogeneity in Evaporation

2020 ◽  
Vol 13 (1) ◽  
pp. 93
Author(s):  
Pavel Kishcha ◽  
Boris Starobinets
Keyword(s):  
Surface Temperature ◽  
Spatial Heterogeneity ◽  
Sea Surface Temperature ◽  
Land Surface ◽  
Dead Sea ◽  
Bulk Water ◽  
Sea Surface ◽  
Maximal Surface ◽  
Water Mixing ◽  
The Dead

Spatial heterogeneity in Dead Sea surface temperature (SST) was pronounced throughout the daytime, based on METEOSAT geostationary satellite data (2005–2015). In summer, SST peaked at 13 LT (local time), when SST reached 38.1 °C, 34.1 °C, and 35.4 °C being averaged over the east, middle, and west parts of the lake, respectively. In winter, daytime SST heterogeneity was less pronounced than that in summer. As the characteristic feature of the diurnal cycle, the SST daily temperature range (the difference between daily maxima and minima) was equal to 7.2 °C, 2.5 °C, and 3.8 °C over the east, middle, and west parts of the Dead Sea, respectively, in summer, compared to 5.3 °C, 1.2 °C, and 2.3 °C in winter. In the presence of vertical water mixing, the maximum of SST should be observed several hours later than that of land surface temperature (LST) over surrounding land areas due to thermal inertia of bulk water. However, METEOSAT showed that, in summer, maxima of SST and LST were observed at the same time, 13 LT. This fact is evidence that there was no noticeable vertical water mixing. Our findings allowed us to consider that, in the absence of water mixing and under uniform solar radiation in the summer months, spatial heterogeneity in SST was associated with inhomogeneity in evaporation. Maximal evaporation (causing maximal surface water cooling) took place at the middle part of the Dead Sea, while minimum evaporation took place at the east side of the lake.

scholarly journals Long-Term Sea Surface Temperature Variability along the U.S. East Coast

2010 ◽  
Vol 40 (5) ◽  
pp. 1004-1017 ◽  
Author(s):  
R. Kipp Shearman ◽  
Steven J. Lentz
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
East Coast ◽  
Atmospheric Temperature ◽  
Coastal Ocean ◽  
Temperature Trend ◽  
Sea Surface ◽  
Temperature Trends ◽  
Cape Hatteras

Abstract Sea surface temperature variations along the entire U.S. East Coast from 1875 to 2007 are characterized using a collection of historical observations from lighthouses and lightships combined with recent buoy and shore-based measurements. Long-term coastal temperature trends are warming in the Gulf of Maine [1.0° ± 0.3°C (100 yr)−1] and Middle Atlantic Bight [0.7° ± 0.3°C (100 yr)−1], whereas trends are weakly cooling or not significant in the South Atlantic Bight [−0.1° ± 0.3°C (100 yr)−1] and off Florida [−0.3° ± 0.2°C (100 yr)−1]. Over the last century, temperatures along the northeastern U.S. coast have warmed at a rate 1.8–2.5 times the regional atmospheric temperature trend but are comparable to warming rates for the Arctic and Labrador, the source of coastal ocean waters north of Cape Hatteras (36°N). South of Cape Hatteras, coastal ocean temperature trends match the regional atmospheric temperature trend. The observations and a simple model show that along-shelf transport, associated with the mean coastal current system running from Labrador to Cape Hatteras, is the mechanism controlling long-term temperature changes for this region and not the local air–sea exchange of heat.

Spatial heterogeneity in Dead Sea surface temperature caused by evaporation

2021 ◽  
Author(s):  
Pavel Kishcha ◽  
Boris Starobinets ◽  
Pinhas Alpert
Keyword(s):  
Remote Sensing ◽  
Surface Temperature ◽  
Spatial Heterogeneity ◽  
Sea Surface Temperature ◽  
Land Surface ◽  
Dead Sea ◽  
Sea Surface ◽  
Water Mixing ◽  
Drying Up ◽  
The Dead

<p>The Dead Sea is a terminal hypersaline lake at a unique location at ~430 m below sea level. Over the last several decades the Dead Sea has been drying up due to climate change: its water level has dropped at the rate of ~1 m year<sup>-1</sup>. In this study we investigated the diurnal cycle of spatial heterogeneity in Dead Sea surface temperature (SST) using METEOSAT geostationary satellite data (2005-2015). METEOSAT data showed that, in the summer months, SST peaked at the same time, 13 LT (local time), as land surface temperature (LST) over surrounding land areas. In the presence of water mixing, the maximum of SST should be observed several hours later than that of LST due to thermal inertia of bulk water. The fact that SST and LST peaked at the same time, 13 LT, is evidence that there was no noticeable vertical water mixing. We consider that, in the absence of noticeable water mixing and under uniform solar radiation in the summer months, inhomogeneity in evaporation was the main causal factor of the observed spatial heterogeneity in Dead Sea SST. METEOSAT showed that spatial heterogeneity in SST was pronounced throughout the daytime. In summer, SST peaked at 13 LT, when SST reached 38.1 <sup>o</sup>C, 34.1 <sup>o</sup>C, and 35.4 <sup>o</sup>C being averaged over the east, middle and west parts of the lake, respectively. The above mentioned spatial heterogeneity in daytime SST caused a pronounced asymmetry in land surface temperature between land areas adjacent to the east and west sides of the lake. Maximal evaporation (causing maximal surface water cooling) took place at the middle part of the Dead Sea, while minimum evaporation took place at the east side of the lake. In the nighttime, METEOSAT data showed that SST values were minimal and SST spatial distribution was much more uniform compared to the daytime. We found that, in winter, when maximal solar radiation reached ~500 W/m<sup>2</sup> compared to ~900 W/m<sup>2</sup> in summer, daytime SST non-uniformity was less pronounced than that in summer. As the characteristic feature of the diurnal cycle, SST daily temperature range was equal to 7.2 °C, 2.5 °C, and 3.8 °C over the east, middle and west parts of the Dead Sea, respectively, in summer, compared to 5.3 °C, 1.2 °C, and 2.3 °C in winter.</p><p>Evaporation causes significant drying up of the Dead Sea, especially in the summer months, as the main contributor to maximal water level drop in the lake. However, no measurements of spatial distribution of Dead Sea evaporation have ever been conducted, either in situ or from space. Our findings allowed us to visualize spatial inhomogeneity in evaporation using the obtained heterogeneity in Dead Sea SST.</p><p><strong>Reference:</strong>   Kishcha P. and Starobinets B. (2021). Spatial heterogeneity in Dead Sea surface temperature associated with inhomogeneity in evaporation. <em>Remote Sensing</em>  (Special Issue: Remote Sensing of Lake Properties and Dynamics), 13(1), 93; https://doi.org/10.3390/rs13010093.</p>

Spatial and Seasonal Variability of Long-Term Sea Surface Temperature Trends in Aegean and Levantine Basins

2021 ◽  
Vol 178 (9) ◽  
pp. 3769-3791
Author(s):  
Fevziye Ayça Saraçoğlu ◽  
Burak Aydoğan ◽  
Berna Ayat ◽  
Kebir Emre Saraçoğlu
Keyword(s):  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Seasonal Variability ◽  
Sea Surface ◽  
Temperature Trends
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