Daily variations in stratification in İzmit Bay

THE DIURNAL CHANGES IN STRATIFICATION OF IZMIT BAY LALEHAN CANDEMİR In this study, the two-layered structure of the Izmit Bay was studied with respect to the atmospheric conditions and the effect of conditions on the stratification in the bay was investigated. With this aim, various hourly oceanographic datasets obtained from the buoy which was placed at the Northeast entrance of the bay and the atmospheric datasets obtained from the nearest meteorological stations were analyzed. In the study, although the observation of the seasonal behavior of the surface water layer as well as the daily solar flux effects was possible. The higher differences of the surface temperature then the deeper layers in the water column were noticed in summer period for the day and night conditions. The mechanism of how the stratification dynamics change during the strong northerly winds that blows for long times and how it returned to the original state was analyzed. According to the results, the strong northerly winds cause the water masses to be carried out of the bay and water levels to rise on the northern shores. As a result of this, the stratification is almost lost and current speed is increased in the water column. The results obtained in this study, show the importance of the high frequency measurements in understanding the hydrographic processes the two layered systems. Keywords: İzmit Bay, stratification, temperature-chain data, time series, diurnal changes, wind induced mixing, Richardson number