On the variability of Mediterranean water flow into the Black Sea

Mediterranean water inflow into the Black Sea has been investigated using current measurements at the northern sill of the Strait of Istanbul (Bosphorus). Variability of the inflow and its relation to sea level and atmospheric factors were studied. Current and salinity spectra show internal variability with periods of 3.5 days. This is correlated with N-S wind component and sea level variations. During southerly wind episodes the lower layer flow increases and relatively well-mixed Mediterranean water reaches the Black Sea. During northeasterlies the bottom layer flow decreases and relatively undiluted Mediterranean water flows into the Black Sea. Dominant energy input is in the low frequency (<0.6 cpd) range in salinity and current speed variations. Current speed also displays variability in short period range. Short period of oscillation (21.3) h is attributed to internal and Black Sea diurnal tidal oscillations and sea breeze.