The wind effect on the Kaštela Bay current field
Abstract
The effect of winds on current field of Kaštela Bay at the synoptic scale was analyzed. The analyses were based on the data of four current measurement experiments carried out between 1982 and 1990 and respective wind data at the nearby meteorological station Split-Marjan.
In order to explain the characteristics of the Kaštela Bay, current field on the synoptic scale in terms of linear dynamics, two simple dynamic balances (viscous and EKMAN) were tested. The results of testing of dynamic balances were positive only for the stations in the bay interior. The testing of EKMAN balance for two stations in the bay interior gave appropriate signs and orders of magnitude for respective terms of the equation of motion. The results of the coefficients of bottom friction were satisfactory for one central bay station, assuming the viscous balance and linear parametrization of bottom friction. The value obtained for the bottom friction coefficients was 1.98x10-3 ms-1. The negative correlations between winds and currents obtained in the bottom layer at most stations in the bay inlet, suggesting two-layer circulation, indicating the importance of the pressure gradient force.
The calculations of the exchange rate through the bay inlet give the values of 2500 to 3000 m3s-1 at a wind speed of 10 ms-1 and respective flushing periods of 6 and 5 days.
