Role of quasi-geostrophic currents and inertial waves in elution of fine sediments in the southeastern part of the Baltic

Abstract

Numerical modeling using the Princeton Ocean Model (POM) was performed for the southeastern part of the Baltic with the objective to compare the spatial distribution of the velocity and bottom sediments data in this region. Special attention was focused on the consideration of the influence of the western and northeastern winds, which lead to the formation of the intense quasi-geostrophic currents and may cause very high velocities in the near bottom layer so that the elution of bottom sediments and transport of their fine fractions occurs. Under abrupt changing of wind velocity the effect of elution can intensify due to the generation of inertial internal waves penetrating into the bottom layer. The comparative analysis of spatial distributions of the velocity in the surface and near bottom layers with the bottom sediments data showed that the areas with the highest velocities that were formed under the western and northeastern winds in most cases coincide with the areas where the bottom sediments are presented by coarse fractions: gravel and sands.