Effect of stratification on wind drift of river runoff in the Kara Sea

Abstract

The formation mechanism of the Yenisei and Ob Rivers floodwater lens (detected in the Kara Sea near the eastern coast of Novaya Zemlya in September to October 2007) by wind drift is examined. Numerical calculations of the trajectories of Lagrangian floats launched at the north part of the Yenisei and Ob seaside and transported by drift currents have been performed using actual wind-forcing data. Four different algorithms have been used for calculating the surface drift velocity and the relative wind direction; two account for the effect of density stratification due to the presence of a layer of fresh water on the sea surface. It has been shown that only wind-drift models that take into account the presence of stratification are able to explain the transport of the Yenisei and Ob floodwater to the point of lens detection.