Internal Waves Generated by the Inflow of the Kodor River in the Black Sea

Abstract

The results of studies of internal waves in the shelf zone of the Black Sea in the water area near the mouth of the Kodor River, conducted in June 2021, are presented. Spatial surveys were carried out with ADCP “Rio Grande 600 kHz”, which revealed the main characteristics of currents and the presence of internal waves generated by the river inflow in to the sea. Internal waves were recorded in two sections oriented along the normal to the coastline and extending to depths of 100 m. The observed waves had the features of nonlinear waves, were located on the near-surface thermocline, and had a height of up to 3–6 m. Also short-period internal waves in the form of a train of waves with an apparent period of about 3.5 min were recorded by a chain of thermistors in the coastal zone of the sea. The dispersion curves and eigenfunctions of internal waves were calculated by numerically solving the equation of internal waves, taking into account the velocity shift in the sea. Theoretical data are compared with experimental ones. A significant influence of the river inflow on the parameters of the generated internal waves moving with the flow was revealed. The experimentally observed decrease in wave periods and an increase in their group and phase velocities were confirmed.