Sochi Club

Climate

The climate of the landlocked Black Sea can be characterized generally as continental (i.e., subject to pronounced seasonal temperature variations), although climatic conditions in some parts of the basin are controlled to a great extent by the shoreline relief. A steppe climate, with cold winters and hot, dry summers, is found in the northwestern part of the basin exposed to the influence of air masses from the north.

The southeastern portion of the sea, sheltered by high mountains, experiences a humid subtropical climate, with abundant precipitation, warm winters, and humid summers. In winter, spurs of the Siberian anticyclone (a clear, dry, high-pressure air mass) create a strong current of cold air, and the northwestern Black Sea cools down considerably, with regular ice formation. The winter invasion of polar continental air (which prevails for an average of 185 days annually) is accompanied by strong northeasterly winds, a rapid temperature drop, and frequent precipitation, with the air becoming warm and moist after passing over the milder eastern portions of the sea. Tropical air from the Mediterranean regions (87 days affected on average) is always warm and moist. Occasionally, winds from the Atlantic via eastern Europe bring rain and sharp squalls.

The average January air temperature over the central portion of the sea is about 46° F (8° C) and decreases to between 36° and 37° F (2° and 3° C) to the west. Spring air temperature everywhere approaches 61° F (16° C), rising to about 75° F (24° C) in the summer. Absolute minimums approach -22° F (-30° C) during the winter cold spells in the northwest, while in the Crimea the maximum may reach 99° F (37° C) in summer. Winds are strongest everywhere in the winter, with the cruel northeasterlies reaching hurricane force in the coastal region of Novorossiysk, just to the east of the Kerch Strait, and gale force on the sea itself.

Marine life

Flora and fauna in the Black Sea derive from the Mediterranean, the result of a series of invasions from that area, and Caspian elements dominate in freshwater estuaries and river mouths. It has a rich biological productivity in some zones.

All the main groups of microorganisms, which in total biomass are one and a half times larger than that of the groups of phytoplankton and zooplankton combined, are found in the sea. Most of them occur in a thin surface layer, with a few anaerobic bacteria in the hydrogen sulfide zone (which otherwise is lifeless). The tiny phytoplankton number some 750 species; compared to numbers in the Mediterranean, however, the zooplankton are poorer, with but 80 species, including jellyfish. In coastal areas are found eggs and larvae of invertebrates and fish. The diffusion of sea-bottom (benthic) plants and animals is four to five times poorer than in the Mediterranean, again because of the effects of the hydrogen sulfide layer. In the shallow northwest section, there was a notable extensive field of the water plant known as phillophora, but since the 1960s this field has been drastically reduced by deterioration of the water quality.

There are about 180 species of fish, a fifth of them of commercial importance. The most important are khamsa, sprat, horse mackerel, and others, including the small Black Sea shark. Some seasonal migration of fish occurs, notably through the Bosporus.