Peculiar features of the thermohaline and hydrochemical water structure in the southeastern Laptev Sea

The thermohaline and hydrochemical characteristics of the Lena River’s estuarine zone were investigated in the Buor-Khaya Bay and the southeastern Laptev Sea in September of 2005. A tongue of river water with high nutrient content and increased turbidity was identified in the bay. It is shown that the two-layer structure in the bay is disturbed by warm freshwater lenses. The strong vertical stratification in the shelf zone results in sharply contrasting characteristics of the surface and bottom waters. It is established that the concentrations of biogenic elements regularly change depending on the thermohaline characteristics of the waters and their stratification degree. Stagnant bottom waters with low dissolved oxygen contents and high concentrations of phosphates, nitrates, and ammonium are recorded in the eastern part of the bay. The bottom waters have different hydrochemical characteristics due to their different origin.