The water level in the bosphorus strait and its dependence on atmospheric forcing

Abstract

Based on measurements, taken during a 40-day period in autumn 1993, of air pressure, wind and water levels at the southern and northern ends of the Bosphorus, an analysis of the water level variation is per formed. The water level difference governs the state of flow through the Bosphorus, and during times of high water level difference the lower layer may block. The water level difference is calculated with an average er ror of 5 cm. The northeasterly wind, slightly dominated by the easterly component, is found to exert a large contribution to the water level difference, whereas the air pressure exerts a net contribution mainly through a phase difference between the response at the northern and southern ends of the Bosphorus. The results are utilised in a calculation of water level differences based on a 2-year time series of air pressure, wind speed and direction. A lower layer blocking frequency of 13% is obtained, in accordance with other works.