Seasonal and Regional Variations of Water Temperature Synoptic Anomalies in the Northeastern Coastal Zone of the Black Sea

Climatic annual cycle of root-mean-square (RMS) values of synoptic water temperature anomalies (SWTA) with daily discreteness is analyzed based on observations within 1977-2005 period at hydro-meteostations (HMS) in the northeastern part of the Black Sea. It is shown that SWTA values are statistically associated with their negative mean values testifying the fact that upwelling is a predominant mechanism in generating synoptic water temperature anomalies. In summer of synoptic variability of water temperature increases significantly from the north to south and in winter - from the south to north. Five modes of the intra-annual variability according to the linear tends of SWTA values are revealed. Their phases and parameters are close the steep HMSs (Sochi, Tuapse and Gelendzhik), but are considerably different from the values in the autumn-winter period in Anapa HMS. The first (I), winter mixing mode is the longest one (late November - March) and is characterized by the lowest RMS values of SWTA. Spring growth mode (II) id characterized by a pronounced positive linear trend with a simultaneous decrease in the absolute values of the dispersion relative to the trend. In summer, there are two types of modes, which are characterized by high absolute levels of the same value, but different from each other. One of them (III) can be called "upwelling" mode and another (IV) - mode of "thermal stabilization". Mode (V) starts with the autumn cooling of the sea water. During this mode there is a marked decrease of SWTA values and an increase of their dispersion. It is noted that in the shallow water area (Anapa HMS) the phase shill and mode duration is observed due to the lower thermal inertia of the water column, as well as the unique mode associated with a sharp decrease in wind activity in mid-February is marked.