Production of hypersaline pools in shallow basins by evaporation

Abstract

This paper incorporates a correction to the heat balance equation in the general ocean models by properly quantifying the sun's light that penetrates the ocean surface and reaches the bottom. Part of the light that hits the bottom in shallow pools of water gets absorbed (depending on the albedo of the bottom) and is reradiated as heat thus warming up the waters there significantly. The light that is not absorbed gets reflected back up, and a part of it is absorbed by the water constituents on its way up, while the remaining light leaves the water surface. It was found from our simulations that the temperatures attained by shallow pools depend upon the water depth and bottom albedo. Increased evaporation associated with such shallow water warming leads to the formation of hypersaline waters. This natural salination is found to occur in the shallow basin near the Andros Island in the Bahamas, where the waters are less than 7 m deep. The maximum salinity of these waters is as high as 46 psu in summer. These hypersaline waters being denser than the nearby deep ocean advect, down to depths of 50 m in summer and 75 m in winter.