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

Abstract

The article presents 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. Spatial surveys were carried out with the Rio Grande 600 kHz ADCP, which revealed the main characteristics of currents and the presence of internal waves generated by river inflow into the sea. Internal waves were recorded on two transects 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 heights of up to 3–6 m. Also, short-period internal waves in the form of a wave train with an apparent period of about 3.5 min were recorded by a thermistor chain in the coastal zone of the sea. The dispersion curves and eigenfunctions of internal waves were calculated by numerically solving the internal wave equation, taking into account the velocity shift in the sea. Theoretical data are compared with experimental data. The significant influence of river inflow on the parameters of the generated internal waves moving with the flow was revealed. The experimentally observed decrease in wave periods and increase in their group and phase velocities were confirmed.