The White Sea is located on the serene outskirts of the western part of Russia. This sea belongs to the group of seas of the Arctic Ocean. Unlike all other Arctic seas, the White Sea is located south of the Arctic Circle, only a small northern part goes beyond this circle. The White Sea is deeply cut into the mainland. On almost all sides, the sea has natural boundaries. Only from the Barents Sea is it separated by a conditional line passing from Cape Svyatoy Nos to Cape Kanin Nos. The White Sea is almost everywhere surrounded by land, so it belongs to the group of inland seas.

The White Sea is one of the smallest seas in our country. It covers an area of ​​about 90 thousand km2. The volume of its waters is 6 thousand km3. The average depth of the sea is 67 m, the maximum depth is 350 m.

The bottom of the sea has a complex relief. The deepest parts of the sea are the Basin and the Kandalaksha Bay. The greatest depth was recorded in the outer zone of this bay. A gradual decrease in depth is observed from the mouth to the top of the Dvina Bay. The bottom of the Onega Bay is somewhat higher compared to the bowl of the Basin. At the bottom of the throat of the sea there is an underwater trench, the depth of which reaches about 50 m. It extends along the strait a little closer to the Tersky coast. The most shallow areas are located in the northern part of the sea. Here the depth does not exceed 50 m. The bottom in the north of the sea is uneven. At the Kaninsky coast and the entrance to the Mezen Bay, the bottom is covered with a large number of cans. They are located in ridges, which are called "Northern cats".

Due to the fact that in the northern part of the sea and in the Gorlo area the sea depth is less than in the Basin, water exchange between deep waters and the Barents Sea is very difficult. This feature of the White Sea is reflected in its natural and climatic conditions. The sea is characterized by features of both maritime and continental climates. This is due to the peculiarities of the geographical position: part of the sea is located in the north of the temperate zone, and part is located beyond the Arctic Circle. Also, the climate of the White Sea is influenced by its belonging to the water basin of the Arctic Ocean, the proximity of the Atlantic Ocean, and the almost complete encirclement of land. The influence of the ocean and land is manifested throughout the year.

White Sea

Winter on the White Sea is long and cold. At this time, the entire northern European part of Russia is in the zone of anticyclones, and a zone of cyclones is observed over the Barents Sea. All this causes a predominantly southwestern wind direction. The average wind speed is about 4 - 8 m/s. These winds contribute to the establishment of cloudy weather with low temperatures and heavy snowfalls.

In February, the average air temperature over the expanses of the White Sea is - 14 - 150C. The exception is the northern part, where the temperature is slightly higher: - 90C. The increase in temperature in the north of the sea is associated with the influence of warm Atlantic air masses. If a large amount of relatively warm air comes from the Atlantic, then the wind acquires a southwestern direction, and the air temperature rises to - 6 - 70C. If the White Sea falls under the influence of the Arctic anticyclone, the winds acquire a northeasterly direction. The weather becomes clear, and the air temperature drops to - 24 - 260C (sometimes there is a stronger cooling).

In summer, the weather over the White Sea is mostly cool, with moderate humidity. During this period, the Barents Sea is under the influence of the anticyclone. A zone of cyclones is formed to the south and southeast of the White Sea. In connection with such synoptic conditions, northeast winds are observed over the White Sea, the strength of which reaches up to 2 - 3 points. Cloudy weather prevails, with frequent heavy rains. The average air temperature in July is + 8 - 100C. Cyclones in the Barents Sea contribute to a change in the direction of the wind over the White Sea. The northeast wind is replaced by the southwest, while the air temperature rises to + 12 - 130C. When an anticyclone dominates in the northeastern part of Europe, southeasterly winds are observed over the sea. The weather at this time is mostly clear and sunny. The average air temperature rises to +17 - 190C. Sometimes in the southern regions of the sea the air warms up to + 300С. But for most of the summer over the White Sea, cloudy weather with low temperatures persists. Thus, during the year the weather over the White Sea is constantly changing.

Algae of the White Sea

A fairly large amount of fresh water enters the White Sea. As a result, the water level rises, and excess water flows through the Gorlo into the Barents Sea. Southwest winds favorably influence this water exchange. Due to the fact that the density of the waters of the White and Barents Seas is different, a current is formed directed from the Barents Sea. Thus, the exchange of water masses between the two Arctic seas is carried out. In the White Sea, the tides are well pronounced. A tidal wave directed from the Barents Sea moves along the axis of the Funnel to the top of the Mezen Bay. This wave in the Throat causes waves to propagate into the Pool. There they are reflected from the Summer and Karelian coasts. As a result of the complex interaction of reflected and incident waves, a standing wave arises. It provides tides in the Throat and the White Sea Basin.

The tidal wave reaches its greatest strength in the Mezensky Bay, near the Kanisky coast, Voronka and near the island of Sosnowiec. The tidal wave moves over vast stretches up the rivers. In the Northern Dvina, the tide exerts its influence at a distance of up to 120 km from the mouth. When a tidal wave propagates, a change in the water level in the river is observed. First, the water level rises, then abruptly stops and starts to rise again. Such changes are called "colossus".

Morning. White Sea

Unrest is very often observed in the White Sea. Their number increases by October - November in the northern part and throat of the sea. During this period, disturbances were noted, the strength of which reaches 4-5 points. The small area of ​​the sea prevents the formation of large waves. Most often, the wave height is 1 m. Very rarely, waves of 3 meters in height rise, as an exception, there are waves of 5 m. In July - August, the sea is most calm. During this period, excitement reaches 1 - 3 points.

In the White Sea, fishing, fishing for sea animals and the extraction of algae are widely developed. Mostly in the waters of this sea, navaga, White Sea herring, smelt, cod and salmon are mined. Among marine animals hunted are harp seals, ringed seals and white whales. The White Sea is of great transport importance, since various cargoes, mainly timber and timber, are transported through its waters. In addition, passenger transportation, fish products, and chemical cargoes are developed here.

Located on the northern outskirts of the European part of our country, the White Sea occupies the space between 68°40? and 63°48? With. sh., and 32°00? and 44°30? in. and is entirely located on the territory of Russia. By its nature, it belongs to the seas of the Arctic Ocean, but this is the only one of the Arctic seas that lies almost entirely south of the Arctic Circle, only the northernmost regions of the sea go beyond this circle. Bizarre in shape, the White Sea is deeply incised into the continent, almost everywhere it has natural land boundaries, and only from the Barents Sea it is separated by a conditional border - the line Cape Svyatoy Nos - Cape Kanin Nos. Surrounded by land on almost all sides, the White Sea belongs to the inland seas. In size, this is one of our smallest seas. Its area is 90 thousand km2, the volume is 6 thousand km3, the average depth is 67 m, the maximum depth is 350 m. The modern shores of the White Sea, different in external forms and landscapes, have their own geographical names and belong to different geomorphological types of the Neroven coasts and the bottom topography is complex seas. The deepest areas of the sea are the Basin and the Kandalaksha Bay, in the outer part of which the maximum depth is noted. The depths gradually decrease from the mouth to the top of the Dvina Bay. The bottom of the shallow Onega Bay is slightly elevated above the Basin. The bottom of the Throat of the Sea is an underwater trench about 50 m deep, stretched along the strait somewhat closer to the Tersky coast. The northern part of the sea is the most shallow. Its depths do not exceed 50 m. The bottom here is very uneven, especially near the Kaninsky coast and the entrance to the Mezen Bay. This area is dotted with many cans, which are distributed in several ridges and are known by the name "Northern Cats". The shallow water of the northern part and the Gorlo, compared to the Basin, hinders its water exchange with the Barents Sea, which affects the hydrological conditions of the White Sea. The position of this sea in the north of the temperate zone and partly beyond the Arctic Circle, belonging to the Arctic Ocean, the proximity of the Atlantic Ocean and the almost continuous ring of land surrounding it determine both maritime and continental features in the climate of the sea, which makes the climate of the White Sea transitional from oceanic to mainland. The influence of the ocean and land to a greater or lesser extent manifests itself in all seasons. Winter on the White Sea is long and severe. At this time, an extensive anticyclone is established over the northern part of the European territory of the Union, and intensive cyclonic activity is developed over the Barents Sea. In this regard, predominantly southwestern winds blow in the White Sea at a speed of 4--8 m/s. They bring with them cold cloudy weather with snowfall. In February, the average monthly air temperature over almost the entire sea is 14-15°, and only in the northern part does it rise to 9°, since here the warming influence of the Atlantic Ocean is felt. With significant intrusions of relatively warm air from the Atlantic, southwestern winds are observed and the air temperature rises to 6--7 °. The displacement of an anticyclone from the Arctic into the White Sea region causes northeasterly winds, clearing and cooling down to 24--26 °, and sometimes very severe frosts. Summers are cool and moderately humid. At this time, an anticyclone usually sets up over the Barents Sea, and intense cyclonic activity develops to the south and southeast of the White Sea. With such a synoptic situation, northeast winds with a force of 2-3 points prevail over the sea. The sky is overcast with frequent heavy rains. The air temperature in July is on average 8--10 °. Cyclones passing over the Barents Sea change the direction of the wind over the White Sea to the west and southwest and cause an increase in air temperature to 12--13°. When an anticyclone sets up over northeastern Europe, southeasterly winds and clear sunny weather prevail over the sea. The air temperature rises to an average of 17-19°, and in some cases in the southern part of the sea it can reach 30°. However, cloudy and cool weather still prevails in summer. Thus, there is no long-term stable weather in the White Sea for almost the entire year, and the seasonal change in the prevailing winds is monsoonal in nature. These are important climatic features that significantly affect the hydrological conditions of the sea. Hydrological characteristic. The White Sea is one of the cold Arctic seas, which is associated not only with its position in high latitudes, but also with the hydrological processes occurring in it. The distribution of water temperature on the surface and in the sea column is characterized by great diversity from place to place and significant seasonal variability. In winter, the water temperature on the surface is equal to the freezing temperature and is on the order of 0.5--0.7 ° in the bays, up to 1.3 ° in the Basin and up to -1.9 ° in the Gorla and the northern part of the sea. These differences are explained by unequal salinity in different areas of the sea. In the spring, after the sea is freed from ice, the surface of the water rapidly warms up. In summer, the surface of relatively shallow bays is best heated. The water temperature on the surface of the Kandalaksha Bay in August is on average 14-15°, in the Basin 12-13°. The lowest temperature on the surface is observed in Voronka and Gorla, where strong mixing cools the surface waters to 7-8°. In autumn, the sea cools rapidly and spatial differences in temperature are smoothed out. The change in water temperature with depth occurs differently from season to season in different areas of the sea. In winter, the temperature, close to the surface, covers a layer of 30-45 m, followed by a slight increase to a horizon of 75-100 m. This is a warm intermediate layer - the remnant of summer warming. Below its temperature decreases, and from the horizons of 130-140 m to the bottom it becomes equal to 1.4 °. In spring, the surface of the sea begins to warm up. Heating extends up to 20 m. From here, the temperature drops sharply to negative values ​​at a horizon of 50–60 m. In summer, the thickness of the heated layer increases to 30–40 m. The temperature in it differs little from the surface. From these horizons, at the beginning, an abrupt, and then a more gradual decrease in temperature is observed, and at a horizon of 130-140 m it reaches a value of 1.4 °. In autumn, cooling of the sea surface extends to horizons of 15–20 m and evens out the temperature in this layer. From here to the horizons of 90–100 m, the water temperature is slightly higher than in the surface layer, since in the subsurface (20–100 m) horizons, the heat accumulated over the summer is still preserved. Further, the temperature drops again and from the horizons of 130-140 m to the bottom is 1.4°. In some areas of the Basin, the vertical distribution of water temperature has its own characteristics. The rivers flowing into the White Sea annually pour into it about 215 km3 of fresh water. More than 3/4 of the total flow falls on the share of rivers flowing into the Onega, Dvina and Mezen bays. In high-water years, the Northern Dvina contributes 171 km3, Mezen 38.5 km3, Onega 27.0 km3 of water per year. The Kem, which flows into the western coast, gives 12.5 km3 and Vyg 11.5 km3 of water per year. The remaining rivers provide only 9% of the runoff. The intra-annual distribution of the runoff of the rivers flowing into these bays, which in the spring discharge 60-70% of the water, is also characterized by great unevenness. In connection with the natural regulation by lakes of many coastal rivers, the distribution of their flow during the year occurs more or less evenly. The runoff maximum is observed in spring and amounts to 40% of the annual runoff. Near the rivers flowing from the southeast, the spring flood is sharper. For the sea as a whole, the maximum flow occurs in May, the minimum in February-March. Fresh waters entering the White Sea raise the water level in it, as a result, excess water flows through the Gorlo into the Barents Sea, which is facilitated by the predominance of southwestern winds in winter. Due to the difference in densities of the waters of the White and Barents Seas, a current arises from the Barents Sea. There is an exchange of water between these seas. True, the basin of the White Sea is separated from the Barents Sea by an underwater threshold located at the exit from the Gorla. Its greatest depth is 40 m, which makes it difficult to exchange deep waters between these seas. Approximately 2200 km3 of water flows out of the White Sea annually, and about 2000 km3/year flows into it. Consequently, significantly more than 2/3 of the entire mass of deep (below 50 m) White Sea water is renewed per year. At the exit from the Dvina Bay, the cold deep layers are much closer to the surface than in other areas of the Basin. A temperature of 0°C is observed here only 12-15 m from the surface. K. M. Deryugin (1928) called this region the “pole of cold” in the White Sea. Its formation is explained by the cyclonic circulation of surface waters, in the center of which the deep water rises. It seems to be sucked in from below instead of water leaving from above. The “pole of cold” is very pronounced in summer. In autumn-winter, with the development of vertical circulation, it is less noticeable. When leaving the Kandalaksha Bay, the picture is reversed: warm waters sink deep down. Zero temperature is observed at the 65 m horizon, while in other places on this horizon the temperature usually has negative values. By analogy with the first name, K. M. Deryugin (1928) called this area the “heat pole”. Its existence is associated with the influence of the influx of homogeneous and warmer, in comparison with the surrounding, deep waters from the Throat, i.e., advection of heat. This is confirmed by an increase in the thickness of surface warm waters in the area of ​​the “heat pole” in autumn, when the inflow of deep waters from the Gorlo becomes more intense. The vertical distribution of water temperature in the Throat is fundamentally different. Due to good mixing, seasonal differences consist in the change in the temperature of the entire mass of water, and not in the nature of its change with depth. In contrast to the Basin, here external thermal effects are perceived by the entire mass of water as a whole, and not from layer to layer. The salinity of the White Sea is lower than the average salinity of the ocean. Its values ​​are unevenly distributed on the sea surface, which is due to the peculiarities of the distribution of river runoff, half of which is provided by the Northern Dvina, the inflow of water from the Barents Sea, and the transfer of water by sea currents. Salinity values ​​usually increase from the tops of the bays to the central part of the Basin and with depth, although each season has its own characteristics of salinity distribution. In winter, salinity on the surface is everywhere increased. In the Throat and Funnel it is 29.0--30.0‰, and in the Basin it is 27.5--28.0‰. The mouth areas of the rivers are the most desalinated. In the Basin, the values ​​of surface salinity can be traced to horizons of 30-40 m, from where they increase sharply at first, and then gradually increase towards the bottom. In spring, surface waters are significantly desalinated (up to 23.0‰, and in the Dvina Bay up to 10.0–12.0‰) in the east and much less (up to 26.0–27.0‰) in the west. This is due to the concentration of the main part of the river runoff in the east, as well as the removal of ice from the west, where they form but do not melt, and therefore do not have a desalination effect. Reduced salinity is observed in the layer 5–10 m below; it sharply increases to horizons of 20–30 m, and then gradually rises to the bottom. In summer, salinity on the surface is lower and variable in space. A typical example of the distribution of salinity values ​​on the surface is shown in fig. 20. The range of salinity values ​​is quite significant. In the Basin, desalination extends to horizons of 10-20 m, from here the salinity first sharply and then gradually increases to the bottom (Fig. 21). In bays, desalination covers only the upper 5-meter layer, which is associated with compensatory flows that compensate for the loss of water carried by runoff surface currents. A. N. Pantyulin noted that due to the difference in the thickness of the layer of low salinity in the bays and in the Basin, the maximum of desalination, obtained by calculating the depth-integrated salinity, is associated with the latter. This means that the central part of the Basin is a kind of reservoir of relatively fresh water coming from the Dvina and Kandalaksha bays. This is a peculiar hydrological feature of the White Sea. In autumn, salinity on the surface increases due to a decrease in river flow and the beginning of ice formation. In the Basin, approximately the same values ​​are observed up to horizons of 30-40 m, from here they increase to the bottom. In the Gorlo, Onega, and Mezen bays, tidal mixing makes the vertical distribution of salinity more uniform throughout the year. The density of the White Sea water primarily determines salinity. The highest density is observed in Voronka, Gorlo and the central part of the Basin in autumn and winter. In summer, the density is reduced. Density values ​​increase quite sharply with depth in accordance with the vertical distribution of salinity, which creates a stable stratification of waters. It makes wind mixing difficult, the depth of which during strong autumn-winter storms is approximately 15–20 m, and in the spring-summer season it is limited to horizons of 10–12 m. convection in most of the sea is only up to horizons of 50–60 m. Somewhat deeper (80–100 m) winter vertical circulation penetrates near the Gorlo, where this is facilitated by intense turbulence associated with strong tidal currents. The limited depth of distribution of autumn-winter convection is a characteristic hydrological feature of the White Sea. However, its deep and bottom waters do not remain in a stagnant state or extremely slow refreshment in the conditions of their difficult exchange with the Barents Sea. The deep waters of the Basin are formed annually in winter as a result of mixing of surface waters entering the Funnel from the Barents Sea and from the Throat of the White Sea. During ice formation, the salinity and density of waters mixed here increase and they slide down the slopes of the bottom from the Gorlo to the bottom horizons of the Basin. The constancy of temperature and salinity of the deep waters of the Basin is not a stagnant phenomenon, but a consequence of the uniform conditions for the formation of these waters. The structure of the White Sea waters is formed mainly under the influence of desalination by continental runoff and water exchange with the Barents Sea, as well as tidal mixing, especially in the Gorla and Mezen Bay, and winter vertical circulation. Based on the analysis of the curves of the vertical distribution of oceanological characteristics, V. V. Timonov (1950) identified the following types of water in the White Sea: Barents Sea (in their pure form are presented only in the Voronka), desalinated waters of the tops of the bays, waters of the upper layers of the Basin, deep waters of the Basin, waters Throat. The application of T, S-analysis to different areas of the White Sea allowed A. N. Pantyulin (1975) to establish the existence of two water masses in shallow (up to 50 m depth) parts of the sea. In the deep areas of the Basin and the Kandalaksha Bay, the surface layer is traced, significantly warmed up and desalinated in summer, intermediate (T = ?0.7–1.0°, S = 28.5–29.0‰) with a core in most cases at the m, deep - highly saline with a temperature close to freezing, water masses. The noted structure of the waters is a characteristic hydrological feature of the White Sea. The horizontal circulation of the White Sea waters is formed under the combined influence of wind, river runoff, tides, compensatory flows, so it is diverse and complex in detail. The resulting movement forms a counterclockwise movement of waters, characteristic of the seas of the Northern Hemisphere. Due to the concentration of river runoff, mainly in the tops of the bays, a waste current arises here, directed to the open part of the Basin. Under the influence of the Coriolis force, the moving waters are pressed against the right bank and leave the Dvina Bay along the Zimny ​​Coast to the Gorlo. At the Kola coast, there is a current from the Gorlo to the Kandalaksha Bay, from which the waters move along the Karelian coast to the Onega Bay and flow out of it near its right bank. In front of the entrance from the bays in the Basin, weak cyclonic gyres are created between the waters moving in opposite directions. These cycles cause anticyclonic movement of waters between them. Around the Solovetsky Islands, the movement of waters is traced clockwise. The velocities of constant currents are small and usually equal to 10-15 cm/s, in narrow places and near capes they reach 30-40 cm/s. Tidal currents have much higher speeds in some areas. In Gorlo and Mezensky Bay they reach 250 cm/s, in Kandalaksha - 30-35 cm/s and Onega Bay - 80-100 cm/s. In the Basin, tidal currents are approximately equal in speed to constant currents. The tides are well expressed in the White Sea. A translational tidal wave from the Barents Sea propagates along the axis of the Funnel to the top of the Mezen Bay. Passing across the entrance to the Gorlo, it causes waves passing through the Gorlo to the Basin, where they are reflected from the Summer and Karelian coasts. The addition of waves reflected from the coast and oncoming waves creates a standing wave, which creates tides in the Gorlo and the White Sea Basin. They have a regular semidiurnal character. Due to the configuration of the shores and the nature of the bottom topography, the highest tide (about 7.0 m) is observed in the Mezensky Bay, near the Kaninsky coast, Voronka and at about. Sosnovets, in the Kandalaksha Bay it slightly exceeds 3 m. In the central regions of the Basin, the Dvina and Onega bays, the tides are less. The tidal wave travels long distances up rivers. In the Northern Dvina, for example, the tide is noticeable 120 km from the mouth. With this movement of the tidal wave, the water level in the river rises, but suddenly it stops its rise or even drops slightly, and then continues to rise again. This process is called "maniha" and is explained by the influence of various tidal waves. In the mouth of the Mezen, wide open to the sea, the tide delays the river current and forms a high wave, which, like a water wall, moves up the river, its height is sometimes several meters. This phenomenon is called “rolling” here, on the Ganges - “boron”, and on the Seine - “mascara”.

Which lies almost entirely south of the Arctic Circle. Difficult in terms of coastline outlines, the White Sea is deeply cut into the continent. It has natural land borders, and only a conditional border separates it from the Barents Sea - the line Cape Svyatoy Nos on - Cape Kanin Nos on the Kanin Peninsula.

The White Sea belongs to the inland seas. Its area is 90.1 thousand km2, volume - 6 thousand km2, average depth - 67 m, maximum depth - 351 m.

Different in external forms and landscapes, the shores of the White Sea have local names - Summer Coast, Winter Coast, Tersky Coast, etc. and belong to different geomorphological types.

According to the shape of the coastline and the nature of the bottom, seven areas are distinguished in the sea: Funnel, Throat, Basin and bays: Kandalaksha, Mezenskaya Bay, Dvinskaya Bay, Onega Bay.

The deepest areas of the sea are the Basin and the Kandalaksha Bay. The depths gradually decrease from the Basin (about 200 m deep) to the top of the Dvinskaya Bay. The bottom of the shallow bay of Onega Bay is somewhat elevated above the bowl of the Basin. The bottom of the Throat of the Sea is an underwater trench with a depth of 50 to 100 m, stretched along the strait somewhat closer to the Tersky coast.

The northern part of the sea is the most shallow. The bottom here is very uneven (especially near the Kaninsky coast), the depths do not exceed 50 m.

The climate of the White Sea is transitional from oceanic to continental. Winter is long and severe. Summers are cool and moderately humid.
In the White Sea, for almost the entire year, there is no long-term stable weather, and the seasonal change in the prevailing winds is monsoonal in nature.

The structure of the White Sea waters is formed mainly under the influence of desalination by continental runoff and water exchange with , as well as tidal mixing (especially in the Gorlo and Mezen Bay) and winter vertical circulation. The waters of the Barents Sea stand out here (in their pure form only in the Voronka), desalinated waters of the tops of the bays, waters of the upper layers of the Basin, deep waters of the Basin, waters of the Gorla.

The distribution at the surface and at depth is characterized by great diversity and significant seasonal variability.
The presence of a warm intermediate layer is a characteristic feature of the White Sea.

The rivers flowing into the White Sea annually bring about 215 km3 of fresh water. More than 3/4 of the total flow falls on rivers flowing into bays: Onega Bay, Dvinskaya Bay, Mezenskaya Bay. In high-water years, the rivers: the Northern Dvina contributes about 170 km3, the Mezen - 38 km3, the Onega - 27 km3 of water per year. The Kem and Vyg rivers flowing on the western coast of the sea provide 12 km3 and 11 km3 of water per year, respectively. Other rivers provide only 9% of the flow.

Large rivers release 60–70% of their water in spring. The runoff maximum is observed in spring and amounts to 40% of the annual runoff. For the sea as a whole, the maximum flow occurs in May, the minimum - in February - March. During the year, more than 2/3 of the entire mass of deep (below 50 m) White Sea water is renewed.

The horizontal circulation of the White Sea waters is formed under the influence of wind, tides and compensatory flows. The resulting movement of the waters of the White Sea occurs counterclockwise, which is typical of the seas of the northern hemisphere.

The velocities of surface currents are low and usually equal to 10–15 cm/s; in narrow places and near capes they reach 30–40 cm/s. Tidal currents have much higher speeds in some areas. They reach 250 cm/s in Gorlo and Mezen Bay, 30–35 cm/s in Kandalaksha Bay and 80–100 cm/s in Onega Bay.

The level of the White Sea experiences non-periodic surge changes. The greatest surges are observed in the autumn-winter season with northwestern and northeastern winds. The level rise can reach 75–90 cm. The strongest surges are observed in winter and spring with southwestern winds. The level at this time drops to 50–75 cm.

Every winter the White Sea is covered with ice, and in spring it completely disappears, so the sea belongs to the seas with seasonal ice cover. The White Sea ice is 90% floating ice. A very significant feature of the ice regime of the White Sea is the constant removal of ice into the Barents Sea. Floating ice has a thickness of 35–40 cm, but in severe winters it can reach 135 cm, even 150 cm. Fast ice in the White Sea occupies a very small area. Its width does not exceed 1 km.

The Arctic Ocean (the only one located almost entirely south of the Arctic Circle), deeply incised into the land. It is located entirely within Russia. It is connected in the north with the Barents Sea by the narrow Gorlo Strait, the northern wide part of which is called the Voronka Strait, the central part of the sea is called the Basin. It borders on the Barents Sea along the line of Cape Svyatoy Nos (on the Kola Peninsula) - Cape Kanin Nos. One of the smallest seas on Earth. The area is 90 thousand km 2, the volume is 6 thousand km 3. The greatest depth is 350 m. The heavily indented coastline of the White Sea forms numerous bays (bays), the largest are Onega, Dvinskaya, Mezenskaya, Kandalaksha Bay. Large islands - Solovetsky, Veliky, Morzhovets, Oleniy, many small islands. The shores of the White Sea, which have their own names, are mostly low-lying, abrasion, with traces of glacial processing. The Tersky coast is predominantly accumulative, the Kandalaksha, Karelian and a significant part of the Pomeranian are of the fjord-skerry type, most of the Onega, Summer and Winter coasts belong to the abrasion-accumulative type of leveled coasts, the Abramovsky and Konushinsky coasts of the Mezen Bay are actively eroded abrasion. Along the Konushinsky coast there are wide sandy-silty drylands (laids).

Relief and geological structure of the bottom. The White Sea basin is located partly on the margin of the Baltic Shield of the ancient East European Platform, and partly on the Russian Plate, where the Early Precambrian crystalline basement is overlain by sedimentary rocks of the Lower and Middle Paleozoic. The deepest areas of the White Sea are in the Kandalaksha Bay (over 300 m) and in the Basin (about 200 m), from which the depths gradually decrease towards the top of the Dvina Bay. The remaining areas of the sea are shallow, especially the Onega and Mezen bays. In the latter, there are many sandy movable shoals called cats (for example, Northern Cats). The throat is a wide trench with depths at the threshold of about 40 m, which makes it difficult to exchange water with the Barents Sea. Bottom sediments in shallow waters and in areas with significant velocities of near-bottom currents are represented mainly by sand, pebbles, boulders, in the Basin and Dvinskaya Bay - fine-grained clayey silt; ferromanganese nodules were found in Gorlo and other areas.

Climate. The White Sea is characterized by a transitional climate from subarctic maritime to temperate continental. Winter is cold and long. Air temperatures in February average -15°С, the minimum is up to -26°С, the highest is at the outlet of the Funnel (-9°С), which is explained by the warming effect of the coastal branch of the North Cape Current in the Barents Sea. Summer is short and cool. Northeast winds bring rainy weather with a temperature in July of 8-10°C. With southwestern winds, sunny weather sets in with temperatures up to 18°C. The highest temperatures are observed in the southern part of the White Sea (up to 30°С). The annual amount of precipitation is about 600 mm. Frequent fogs.

Hydrological regime. River runoff in the White Sea averages about 215 km 3 per year. Large rivers - the Northern Dvina, Mezen, Onega, Kem and Vyg - provide over 90% of the total river flow, and up to 70% during the spring flood. Along the shores of the Kola Bay, relatively cold and salty Barents Sea waters enter the White Sea, 2000 km 3 per year. In the opposite direction, along the southeastern shore of the Gorla and the eastern shore of the Funnel, White Sea waters flow out, about 2200 km 3 per year, up to 70% of the White Sea water is renewed in a year.

In the deep-water parts of the White Sea, three water masses are distinguished: surface, warmed up and rather desalinated during the warm period, intermediate (temperature from -0.7 to 1 ° C, salinity 28.5-29‰) and deep, with high salinity and temperature, close to freezing in shallow water - two.

Surface circulation is generally created by a flow that is counterclockwise. Several differently directed cycles are observed in the Basin. The speed of the currents is on average about 10-15 cm/s, in narrowings and near capes - up to 30-40 cm/s, in Gorlo and in the Mezen Bay it reaches 250 cm/s.

The tides in the White Sea are regular semi-diurnal. The highest tide at the top of the Mezen Bay is up to 10 m, in the Kandalaksha Bay it is about 3 m. Surge fluctuations in the level are most noticeable in the cold season. In autumn and winter, with northeast and northwest winds, the strongest surges are observed, up to 90 cm high, in winter and spring, with southwestern winds, the strongest surges, up to 75 cm high. The strongest waves, 4-5 points, are noted autumn in the Funnel and Throat. Waves up to 1 m high prevail, rarely up to 5 meters.

The water temperature on the surface in summer averages from 7°C at the entrance to the Funnel to 15°C in the tops of the bays, in winter from -0.5°C in the bays to -1.9°C in the Gorla. All this leads to the fact that the salinity of the surface layer over most of the sea area is significantly lower than the average oceanic one. In winter, salinity is higher than in summer, in Voronka and Gorla 29-30‰, in the Basin 27.5-28‰, in bays 23-25‰. In summer, salinity contrasts in different areas of the sea are much higher: from 34‰ in the northwestern part of the Voronka to 10‰ at the top of the Dvinskaya Bay.

The White Sea is covered with ice every winter and belongs to the seas with seasonal ice cover. At the end of October, ice appears at the top of the Mezen Bay, in January - in Voronka and Gorla. Up to 90% of all sea ice in the White Sea is drifting; landfast ice occupies a narrow coastal strip, usually no more than 1 km. The White Sea ice is constantly carried into the Barents Sea. Ice thickness is on average 35-40 cm, but in especially severe winters fast ice can freeze up to 150 cm. The destruction and melting of the ice cover usually begins at the end of March in Voronka, at the end of May - beginning of June the sea is completely freed from sea ice.

Research History. The first, not later than the beginning of the 11th century, the Novgorodians began to master the White Sea, who settled on its shores and subsequently received the name Pomors. The difficult fishing conditions forced the Pomors to study tidal phenomena, the nature of winds and sea currents, and develop their own navigation methods. The first hydrographic information about the White Sea dates back to the middle of the 16th century. The general inventory of the White Sea was made in 1798-1801. Detailed work on surveying and measurements was carried out in 1827-32 by the Russian scientist M.F. Reinecke, who published the Atlas of the White Sea. The first sailing direction of the White Sea was published in 1850. In 1891-1902, under the leadership of N.M. Knipovich, complex studies of the deep-sea part of the sea were carried out. In the 20th - early 21st centuries, the research of the White Sea is carried out with the help of a network of hydrometeorological stations, as well as expeditions of the State Committee for Hydrometeorology, the Ministry of Science and Education, the Russian Academy of Sciences, etc.

Economic use. The White Sea is rich in bioresources; the benthic fauna includes over 700 species. Of the 50 species of fish, salmon, trout, navaga, polar cod, flounder, smelt, White Sea herring and White Sea cod are of commercial importance. From the end of the 15th to the beginning of the 18th centuries, the most important sea route ran through the White Sea, connecting Russia with Western Europe. The transport significance of the White Sea has been preserved at the beginning of the 21st century. Through the White Sea-Baltic Canal (near the city of Belomorsk), it is connected to the Baltic Sea, and the Volga-Baltic Waterway - to the Volga. Main ports: Arkhangelsk, Onega, Belomorsk, Kandalaksha.

The ecological state of the White Sea is generally stable and relatively favorable. The concentration of pollutants increases in the estuarine zones of rivers, in bays, in places where the fleet is concentrated, which leads to some reduction in the size of hydrobionts in coastal areas.

Lit .: Dobrovolsky A.D., Zalogin B.S. Seas of the USSR. M., 1982; Zalogin B.S., Kosarev A.N. Seas. M., 1999.

The seas are like large natural complexes.

Goals and objectives of the lesson:

To form ideas about the nature of the White and Azov Seas. Show the relationships between the components of the sea. Expand knowledge about natural complexes.

Equipment:

Physical map of Russia, map of the oceans, table of the sea of ​​Russia, movie of the sea of ​​Russia.

During the classes.

1. Organizing time.

2. Repetition. Checking homework.

Remember what a natural complex is, and what components of land it consists of.

Why are natural complexes diverse?

Name the components of any natural complex.( Relief, rocks, soil, plants, animals, climate, water).

Who founded the science that studies PTK? ( ).

What is it called? (Landscape science).

3. Learning new material.

Natural complexes exist not only on land, but also in the ocean. The seas are natural complexes consisting of bottom rocks, water, flora and fauna. Man has been using the resources of the seas for a long time. The significance of the interconnections between the components of the sea will help to rationally use its resources.

Today we will get acquainted with the complexes of the White and Azov Seas. Find them on the map.

In the Sea of ​​Azov, find the Kerch Strait, the Sivash Bay, the rivers flowing into the Sea of ​​Azov: Don, Kuban.

In the White Sea - the Strait of the Throat of the White Sea, Cape Svyatoy Nos, Cape Kanin Nos, Kandalashsky Bay, lips - Onega, Mezenskaya, Dvinskaya; Find the rivers flowing into the White Sea: Northern Dvina, Mezen, Onega. The mouths of these rivers are flooded with water of the White Sea, have a funnel shape, they are called estuaries.

About the seas - internal, connected with the oceans by narrow straits, therefore they have a special appearance, they are special complexes. Let's get to know each other in more detail with the White Sea.

1gr. To characterize the natural complex of the White Sea according to the plan:

4) Temperature (freezes?)

5) Salinity of water.

8) Rivers flowing into the sea.

9) Biological resources.

10) Problems of the sea.

Acquaintance with the PTC of the White Sea

WHITE SEA, inland sea Arctic Ocean, off the northern coast of the European part of the Russian Federation. 90 thousand km2. Large islands: Solovetsky, Morzhovets, Mudyugsky. In winter it is covered with ice. Tides up to 10 m (in the Mezen Bay).

The White Sea in the north is connected by the Gorlo Strait of the White Sea with the Barents Sea. The sea has low-lying, but strongly indented shores; this is the Kandalaksha Bay and lips (they are called estuaries). Onega, Dvinskaya, Mezenskaya. The White Sea is small in size. The bottom relief is uneven. The sea is not deep. The average depth is 67 m. the maximum depth is 350 m. It is located on the continental shelf. The salinity of the White Sea is less than that of the Barents Sea, in the bays 10-14%o. In the north, salinity is higher (30%o) than in the south - 20-26%o. because in the south, the rivers Onega, S. Dvina, Mezen flow into the sea, which freshen the water of the White Sea, especially in the bays. The biological resources of the White Sea are poorer than those of the Barents Sea. The White Sea is colder than the Barents Sea, into which a warm current enters, the White Sea freezes. Of the fish, herring, salmon, trout, cod and others live here. Ports: Arkhangelsk, Onega, Belomorsk, Kandalaksha, Kem, Mezen. It is connected with the Baltic Cape of the White Sea-Baltic Canal, with the Azov, Caspian and Black Seas by the Volga-Baltic Waterway.

In the White Sea is the Kandalaksha Nature Reserve, where eider nesting sites are protected. This bird lines its nests with its fluff, which has the ability to retain heat. The fluff is light. People collect eider down.

Acquaintance with the PTC of the Sea of ​​Azov

2gr. To characterize the natural complex of the Sea of ​​\u200b\u200bAzov according to the plan:

1) Which ocean basin does the sea belong to?

2) Internal or marginal (connection with the ocean).

3) Area compared to other seas,

4) Temperature (freezes?)

5) Salinity of water.

6) Depths prevailing and greatest (conclusion - deep, shallow).

7) Influence of depth on other components (salinity, temperature, organic world).

8) Rivers flowing into the sea.

9) Biological resources.

10) Problems of the sea.

SEA OF AZOV(other Russian - Surozh Sea), in the south of the East European Plain. Kerch Prospekt. connected to the Black Sea. 39 t. km2 Belongs to the Atlantic Ocean basin, inland. It is shallow, the depth is 5-7 m. In some places up to 15 m. Large bays: Taganrog, Sivash. Large rivers fall into Don and Kuban. Freezes for 2-3 months. From the end of December to the end of February - the beginning of March. The waters of the rivers significantly desalinate the sea water at their confluence - up to 5-6‰ with an average salinity of 11-13‰. The temperature of sea water in summer is +25.30˚С, in winter it is below 0˚. Fishing (anchovy, sprat, bream, pike perch). Main ports: Mariupol, Taganrog, Yeysk, Berdyansk. Resorts. As a result of anthropogenic impacts, the ecological situation has deteriorated; a search is underway for scientifically based ways of restoring the natural complexes of the Azov m.

To consolidate and create an image of the sea, show the presentation "White and Azov Seas" during the test of independent work.

Summing up the lesson.

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