Influence of quasi-geostrophic currents and inertial waves on the elution of fine sediments in the Southeast Baltic

Abstract

Numerical simulation based on the Princeton Ocean Model (POM) was performed for a region of the Southeast Baltic in order to compare data on the spatial distribution of velocity and bottom sediments. Special attention was focused on the influence of western and northeastern winds, which generate intense quasi-geostrophic currents can may cause very high velocities in the near bottom layer, which results in the elution of bottom sediments and transport of their fine fractions. An abrupt change in wind velocity intensifies the effect of elution due to generation of inertial internal waves that penetrate into the bottom layer. The spatial distributions of the velocity in the surface and near bottom layers are compared with data on bottom sediments. It turned out that areas with the highest velocities that formed under the effect of western and northeastern winds in most cases coincide with areas where bottom sediments are represented by coarse-grain fractions of gravel and sands.