Baltic Sea and its fresh waters - causes and effects

Weather Arabs - is the Baltic (Sea The Baltic Sea) north of Europe, one of the Atlantic Ocean arms , but the water exchange between them is limited, where it connects the Baltic Sea through the Straits of Danish Sea and Skagerrak North Sea, and connects to the North Atlantic Ocean Sea from the south through the Strait of Dover, as The Baltic Sea is connected by artificial waterways to the White Sea (the White Sea Channel), and to the German Gulf of the North Sea via the Kiel Canal.

Baltic Sea site

The Baltic Sea extends from a latitude of 53 degrees to a latitude of 66 degrees north, and a longitude from 10 degrees to 30 degrees east, and is surrounded on its eastern side by Estonia, Finland, Latvia, Lithuania and Russia, and Sweden and Denmark are located to the west, and is bordered on the south by Germany, Poland and the plain of Northern and Central Europe The Baltic Sea is bounded by the northern edge, the land Islands and the Gulf of Bothnia, and on the northeastern edge the Gulf of Finland, the Gulf of Riga on the eastern edge, and on the western edge the Swedish part of the southern Scandinavian Peninsula.

Origin of the Baltic Sea

The Baltic Sea is a shrinking remnant of the area covered with water resulting from the melting of the Scandinavian ice sheet, which retreated towards the North Pole at the end of the Ice Age. About 14,000 years ago, ice covered all of northern Europe as far south as the present German-Polish coast, after which limited areas remained. The stagnant ice in northern Sweden, and a lake of fresh water extending from the Arctic in Sweden and Finland to the present southern Baltic, and then subsequent changes led to the extension of water across the land bridge between the present Baltic Sea and the North Sea until the Jutland peninsula was fragmented by several water straits, and began The water level is slowly rising in many lowland areas surrounding the sea until the Baltic Sea.

Baltic Sea climate

The climate of the Baltic is described as monsoon, the winters are long and cold, the summers are short and relatively warm, with average temperatures ranging from about -10 ° C over the Gulf of Bothnia and Finland in mid-winter to about 17 ° C on the southern parts of the Baltic Sea in midsummer. The climate of the Baltic is fluctuating, with mild marine weather extending from the North Atlantic at times to the Baltic Sea, and continental influences prevail at other times, giving periods of severe cold in winter and warm and dry weather in summer.

The pattern of precipitation varies according to the type of weather, as the average precipitation ranges between 500-600 mm annually, and cloudy weather prevails and fog becomes more frequent in the spring and early summer, and the winds tend to be variable, but they do not usually reach the strength of the storm. Sea breezes are usually over coastal areas in summer.

Causes and effects of the freshness of the waters of the Baltic Sea

The Baltic Sea is characterized by fresh water, and this is due to several reasons. The Baltic is an almost closed sea, its outlets are very shallow, and the longest rivers that flow into it pass through regions with a temperate continental climate, which keeps water evaporation rates low, and increases tributary water with melting snow in the spring, and this Reduces the salinity of the waters of the Baltic Sea, the highest salinity recorded in the western Baltic is about 10 parts per thousand at the surface, and about 15 parts per thousand near the bottom, and the lowest level is located at the head of the Gulf of Bothnia, where the salinity ratio is less than a third of this value .

(Rivers flowing into the Baltic Sea)

But the low salinity and shallow coastal waters cause the accumulation of ice at the head of the Gulf of Bothnia and off Finland in most winters, until the height of the accumulated ice sometimes reaches about 15 meters, and floating ice forms in the land Islands region and its north, and in the inner reaches of the Gulf of Finland, reaching Its depth is about one meter, and movement between Stockholm, Turku and Helsinki in Finland becomes not possible in harsh winters, and the ice can close the ports for several days along the Polish and German coasts, and in the summer the surface waters remain cold, but temperatures in the depths remain very low. .

(Snow accumulation in the Baltic)

Among the factors that contribute to determining the salinity of the waters of the Baltic are the currents exchanged between it and the North Sea, despite the fact that the location of the Baltic Sea makes it protected from tidal currents that occur in the North Sea, there are water currents that flow between them, so the great flow of river water and surface runoff, Including the water produced by the snowmelt in the spring, it causes the surface water to flow from the Baltic Sea towards the North Sea, and in return there is a deeper countercurrent than the denser salt water flowing from the North Sea to the Baltic.

The winds may play an important role in the water exchange, as the strong northeast winds lead to high waves along the southern shores, which leads to coastal floods, and on the contrary, the southwest winds contribute to the formation of sand dunes along the German and Polish coasts and also cause In the accumulation of water in the northern Baltic.