Tides in the Black Sea: Observations and Numerical Modelling

Abstract

Longterm hourly data from 28 tide gauges were used to examine the main features of tides in the Black Sea. The tides in this basin are directly caused by tide-generating forces and the semidiurnal tides prevail over diurnal tides. Based on the Princeton Ocean Model (POM), a numerical model of tides in the Black Sea and adjacent Sea of Azov was developed and found to be in good agreement with tide gauge observations. Detailed tidal charts for amplitudes and phase lags of the major tidal harmonics in these two seas were constructed. The results of the numerical modelling and observations reveal for the semidiurnal tides the presence of an amphidromy with clockwise rotation and another one with counterclockwise rotation for the diurnal tides, both located in the central part of the sea near the Crimean Peninsula. Therefore, for this part of the sea the amplitudes of harmonics M2 and K1 are less than 0.1 cm. Relatively larger M2 amplitudes are observed on the east and west coasts of the sea (2–3 cm). The maximum amplitude of the harmonic M2 was found at Karkinit Bay—up to 4.5 cm—while the maximum tidal range varies from 1 cm near the Crimean Peninsula to 18–19 cm in the Dnieper–Bug Estuary and Karkinit Bay. Radiational tides, initiated mainly by sea breezes, make an important contribution to the formation of tidal oscillations in the Dnieper–Bug Estuary.