Changes in the rate of evaporation from the dead sea

✍ Scribed by G. Stanhill

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 467 KB
• Volume: 14
• Category: Article
• ISSN: 0899-8418
• DOI: 10.1002/joc.3370140409

✦ Synopsis

Abstract

Heat balance calculations indicate that during the last 40 years a marked decrease in the evaporation rate from the Dead Sea has accompanied its increased salinity. Two‐thirds of the estimated 17 per cent decrease is attributed to the reduced vapour pressure of its now salt‐saturated waters, the remaining one‐third to the reduction in radiation balance caused by the greater longwave loss from its warmer sea surface. The rate of evaporation from a hypothetical Dead Sea with a surface level restored to previous levels by an influx of Mediterranean waters was estimated to be 158 per cent of its current rate, which is 1.05 m per year. Two‐thirds of this increase was attributed to the greater vapour pressure gradient between the less saline surface water and the atmosphere, one‐third to the increased radiation balance at its cooler sea surface. Although the mechanism for these changes are well understood and easily calculated, a number of complex interactions exist between the various effects that do not allow a quantitative relationship to be established analytically between the Dead Sea's surface level or salinity and rate of evaporation. However, empirically, the linear relationship between annual evaporation, E (m year^−1^), and surface density, D (g cm^−3^), E = 4.701 ‐ 2.926 D. accounts for 98 per cent of the variation between evaporation from a salt‐free and from a salt‐saturated Dead Sea.