Where is the East Siberian Sea. East-Siberian Sea. Depth, islands, resources and problems of the East Siberian Sea

November 26, 2006

1. ARCTIC OCEAN…………………………………………….3

2. EAST SIBERIAN SEA………………………………………………4

2.1. Shores………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

2.2. Bottom structure…………………………………………………………………………6

2.3. Characteristic climate……………………………………………………………7

2.4. Hydrological regime……………………………………………………..9

2.5. Ice regime………………………………………………………………13

2.6. Biology…………………………………………………………………………14

REFERENCES…………………………………………………………….15

1. THE ARCTIC OCEAN.

The Arctic Ocean is small compared to other parts of the World Ocean: its area is about 13.1 million km 2 (3.6% of the area of the World Ocean). However, practical and scientific significance research of the Arctic Ocean is very large. The shortest, but also one of the most difficult sea route in terms of ice conditions, runs through it. In addition, it serves as the only sea route to supply the booming industry of Siberia.

Due to its remoteness, harsh climate, and permanent ice cover, the Arctic Ocean has proven to be the least explored of the oceans. By the end of the 19th century almost all of its coastline was mapped in some detail, but most of the ocean itself remained unexplored. Northern tip of Greenland and the Canadian Islands arctic archipelago were completely unexplored. Geographers did not have a single point of view regarding the distribution of land and sea. Some scientists, including the German geographer Petermann, believed that Greenland stretched across the North Pole to Wrangel Land (now Wrangel Island); others believed that the central polar region was composed of numerous islands separated by shallow areas.

During the expedition on the ship Jeannette (1879-1881) it was found that Fr. Wrangel is not adjacent to Greenland. In 1893-1896. Nansen's ship "Fram" drifted with multi-year ice through the Arctic Basin (A. b.) from the Novosibirsk Islands to Spitsbergen. Analysis of the data of eleven measurements of the depths made during this drift showed that the depth of A. b. in this area varies from 3400 to 4000 m. So for the first time it was established that at least part of A. b. occupies a deep basin.

The Arctic Ocean is also interesting from a hydrometeorological point of view. In the North European Basin, there is the most powerful center on Earth of "isoanomalous overheating" of the atmosphere due to the heat of the ocean, the effect of which on atmospheric processes and climatic conditions manifest up to Baikal. The Arctic Ocean, especially its Arctic Basin, plays the role of one of the planetary "sinks" of heat both in the atmosphere and in the ocean.

2. EAST SIBERIAN SEA

The East Siberian Sea is located between the New Siberian Islands and about. Wrangel. Its western border is the eastern border of the Laptev Sea, it runs from the point of intersection of the meridian of the northern tip of about. Boiler house with the edge of the continental shoal (79°N, 139°E) to the northern tip of this island (Cape Anisii), then along the eastern shores of the New Siberian Islands to Cape Svyatoy Nos (Dmitry Laptev Strait). The northern boundary runs along the edge of the continental shelf from the point with coordinates 79°N. sh., 139 ° in. to the point with coordinates 76° N. latitude, 180° east etc., and the eastern border - from the point with these coordinates along the meridian 180 ° to about. Wrangel, then along its northwestern coast to Cape Blossom and further to Cape Yakan on the mainland. The southern border runs along the mainland coast from Cape Yakan to Cape Svyatoy Nos.

The East Siberian Sea belongs to the type of continental marginal seas. Its area is 913 thousand km 2, volume - 49 thousand km 3, average depth- 54 m, the greatest depth is 915 m, i.e. this sea lies entirely on the continental shelf.

2.1. Shores.

The coastline of the East Siberian Sea forms rather large bends, in some places going into the land, in some places protruding into the sea, but there are also areas with a flat coastline. Small meanders are usually confined to the mouths of small rivers.

West coast landscapes East Siberian Sea sharply different from the eastern. In the section from the New Siberian Islands to the mouth of the Kolyma, the coasts are very low and monotonous. Here the swampy tundra approaches the sea. East of the mouth Kolyma, beyond the metro station Bolshoy Baranov, the coast becomes mountainous. From the mouth of the Kolyma to about. Aion directly to the water approach low hills, abruptly breaking off in some places. The Chaun Bay is framed by low, but steep, even banks. Different in relief and structure, the coast of the sea in different areas refers to different morphological types of coasts.

Suspended precipitation carried by rivers causes a change in depths in coastal areas and the formation of bars in the mouths of rivers. The Indigirka River carries out 16.7 million tons of suspended sediments per year, the Kolyma - 8.3 million tons. The liquid runoff of the Kolyma is 132 * 10 3 m 3 / year.

As a result of the warming effect river waters Intense thermal abrasion of the estuarine sections of the coast occurs on the adjacent coastal areas. According to available data, the rate of abrasion ranges from 1-5 to 10-15m/year.

Where the coast is composed of bedrock (the area of Cape Baranov and Cape Shelagsky, West Coast O. Wrangel, etc.), a denudation type of coast is usually developed, since the impact of waves is weakened and physical weathering processes predominate. Accumulative shores with wide sand and pebble bars separating chains of lagoons are found on the southern coast of the Long Strait.

2.2. Bottom structure.

The underwater relief of the shelf that forms the bed of the sea, in general terms, is a plain, very slightly inclined from the southwest to the northeast. The bottom of the sea has no noticeable depressions and hills. Depths up to 20-25 m predominate. The area of shallow depths in the western part of the sea forms the Novosibirsk shoal. The greatest depths are concentrated in the northeastern part of the sea. A noticeable increase in depth occurs in the horizon from 100 to 200 m.

Most of The bottom of the sea is covered with a thin sedimentary cover. In the Tertiary period and at the beginning of the Quaternary, the bottom surface was an almost flat plain, composed of ancient alluvium. river systems paleo-Indigirka and paleo-Kolyma, whose traces on seabed can still be discerned. Most of the archipelagos and individual islands found in the shelf area are composed of rocks of this basement (Medvezhiy, Rautan, Shalaurova Islands, part of Ayon Island, etc.). In the region of the De Long Islands and in the northern part of the sea, there is the so-called Hyperborean platform (according to Shatsky). Aeromagnetic surveys confirm the presence in this area of a solid crystalline basement, overlapped and bordered by Mesozoic rocks, in places crumpled into folds.

The bottom sediments of the shelf consist mainly of sandy silt containing crushed boulders and pebbles; some of them are rubble rocks O. Wrangel or other islands brought by ice.

2.3. Characteristic climate.

Located in high latitudes, the East Siberian Sea is located in the zone of atmospheric influences of the Atlantic and Pacific Oceans. The western part of the sea (although rarely) is penetrated by cyclones of Atlantic origin, eastern regions- Pacific. The climate of the East Siberian Sea is polar maritime, but with signs of continentality.

In winter, the main influence on the sea is exerted by the spur of the Siberian High, which goes to the coast, and the crest of the polar anticyclone is weakly expressed. In this regard, south-westerly and southerly winds prevail over the sea at a speed of 6-7 m/s. They bring cold air from the continent, so the average monthly air temperature in January is about -28-30°. In winter, there is calm, clear weather, which on some days is disturbed by cyclonic intrusions. Atlantic cyclones in the west of the sea cause increased winds and some warming, while Pacific cyclones, which have cold continental air in the rear, only increase wind speed, cloudiness and cause snowstorms in the southeastern part of the sea. In mountainous areas of the coast, the passage of Pacific cyclones is associated with the formation local wind- hair dryer. It usually reaches storm strength, causing some increase in temperature and a decrease in air humidity.

In summer, the pressure over the mainland of Asia is lowered, and over the sea it is increased, so the northerly winds prevail. At the beginning of the season they are very weak, but during the summer their speed gradually increases, reaching an average of 6-7 m/s. By the end of summer, the western part of the East Siberian Sea becomes one of the most stormy sections of the Northern sea route. Often the wind blows at a speed of 10-15 m/s. The strengthening of the wind here is associated with hair dryers. southeastern part the seas are much calmer. Steady north and northeast winds cause low temperature air. The average July temperature is 0-1 ° in the north of the sea and 2-3 e in coastal areas. IN summer time over the East Siberian Sea, the weather is mostly cloudy with light drizzling rain, sometimes it is sleet.

In autumn, there are almost no heat returns, which is explained by the remoteness of the sea from the oceanic centers of atmospheric action and their weak influence on atmospheric processes. Relatively cold summers throughout the sea, stormy weather at the end of summer and especially in autumn in the marginal areas of the sea, and calm in its central part are the characteristic climatic features of the sea. The speed of northwestern and northeastern winds often reaches 20-25 m/s. They cause waves up to 4-5 m high. Western winds contribute to the formation of a warm current going to eastbound from the Kolyma region. It is this warm current that clears the Long Strait of ice. Away from the coast, storm wind speeds often reach 40-45 m/s.

Most of the year the sea is covered with ice. In its eastern part floating ice often stay close to the coast even in summer. Observations carried out at high-latitude stations showed that the direction of ice drift depends on the distribution of atmospheric pressure. In winter, when a high pressure area develops near the pole, the anticyclonic (clockwise) circulation of water increases, which forces the ice to drift in a northwesterly direction. The average daily ice drift speed is 3-8 km.

When the polar anticyclone weakens, the area of cyclonic water circulation expands, which prevents the removal of ice from the area and, conversely, favors the flow of multi-year ice from high latitudes and the accumulation of ice in the Long Strait.

2.4. hydrological regime.

The annual precipitation is 100-200 mm, and the river runoff, unlike the Kara Sea and the Laptev Sea, is not very large. Several significant rivers flow into the East Siberian Sea, the largest of which is the river. Kolyma. Its annual runoff is 132 km3. The second largest runoff river. Indigirka brings 59 km 3 of water. The total continental runoff to the East Siberian Sea is about 250 km 3 /year, which is only 10% of the total river runoff to all Arctic seas. All river water enters the southern part of the sea, and approximately 90% of the runoff falls, as in other Arctic seas, during the summer months.

Given the very vast size of the East Siberian Sea, coastal runoff does not significantly affect its general hydrological regime, but only determines some hydrological features of coastal areas in summer. High latitudes, free communication with the Central Arctic Basin, high ice coverage and low river flow determine the main features of the hydrological conditions of the East Siberian Sea.

The current system of the East Siberian Sea has been poorly studied. The general circulation of the sea waters is cyclonic in nature. From the Sannikov and Dmitry Laptev straits, water moves along the coast to the east. Near about. Wrangel part of the current turns to the north, continuing to move counterclockwise, and the other part passes to the east through the strait. Long (between Wrangel Island and the continental coast). The northward current is drawn into the Transarctic Current, turning to the northwest. Along the eastern shores of the Novosibirsk Islands, apparently, there is a current directed to the south and closing the cyclonic circulation.

Due to the shallow water and the absence of deep trenches extending beyond the northern limits of the East Siberian Sea, the vast majority of its spaces from the surface to the bottom are occupied by surface Arctic waters. Only in relatively limited estuarine areas is a kind of water formed as a result of mixing river and sea waters. It is characterized by high temperature and low salinity.

Constant currents on the surface of the East Siberian Sea form a weakly expressed cyclonic circulation. Along the mainland coast, there is a steady transfer of water from west to east. At Cape Billing, part of the waters is directed to the north and northwest and carried to the northern margins of the sea, where it is included in the streams going to the west. In different synoptic situations, the movement of waters also changes. Part of the water from the East Siberian Sea is carried out through the Long Strait into the Chukchi Sea. Permanent currents are often disturbed by wind currents, which are often stronger than permanent currents. Influence tidal currents relatively small.

Tides. Regular semidiurnal tides are observed in the East Siberian Sea. They are caused by a tidal wave that enters the sea from the north and moves towards the coast of the mainland. Its front is stretched from the north-north-west to the east-south-east from the New Siberian Islands to about. Wrangel.

The tides are most pronounced in the north and northwest. As they move south, they weaken, as the ocean tidal wave is largely damped in the vast shallow water. Thus, in the section from Indigirka to Cape Shelagsky, tidal level fluctuations are almost not noticeable. To the west and east of this area, the tide is also small - 5-7 cm. At the mouth of the Indigirka, the configuration of the banks and the bottom topography contribute to an increase in tides to 20-25 cm. Level changes caused by meteorological reasons are much more developed on the coast of the mainland.

The annual course of the level is characterized by its highest position in June - July, when there is an abundant inflow of river waters. The decrease in continental runoff in August leads to a decrease in the level by 50-70 cm. As a result of the predominance of surge winds in autumn, in October, the level rises.

In winter, the level drops and in March - April reaches its lowest position.

In the summer season, surge phenomena are very pronounced, in which level fluctuations are often 60-70 cm. At the mouth of the Kolyma and in the Dmitry Laptev Strait, they reach their maximum values for the entire sea - 2.5 m. one of characteristic features coastal areas of the sea.

Significant waves develop in the ice-free areas of the sea. It is strongest during stormy northwestern and southeastern winds, which have the largest accelerations over the surface. clean water. The maximum wave heights reach 5 m, usually their height is 3-4 m. Strong waves are observed mainly in late summer - early autumn (September), when the ice edge recedes to the north. West Side the sea is more stormy than the eastern one. Its central regions are relatively calm.

Water temperature on the surface in all seasons generally decreases from south to north. In winter, it is close to the freezing point and near the mouths of the rivers is -0.2-0.6 °, and at northern borders seas - 1.7-1.8 °. In summer, the distribution of surface temperature is determined by the ice conditions. The water temperature in bays and bays reaches 7-8°, in open, ice-free areas 2-3°, and near the ice edge it is close to 0°.

The change in water temperature with depth in winter and spring is hardly noticeable. Only near the mouth major rivers it drops to -0.5° in the subglacial horizons and to -1.5° near the bottom. In summer, in free otold spaces, the water temperature drops slightly from the surface to the bottom in coastal zone in the west of the sea. In its eastern part, surface temperature is observed in the 3-5 m layer, from where it drops sharply to 5-7 m horizons and then gradually decreases to the bottom. In the zones of influence of coastal runoff, a uniform temperature covers a layer up to 7-10 m, between horizons of 10-20 m it sharply, and then gradually decreases to the bottom. The shallow, slightly warm East Siberian Sea is one of the coldest Arctic seas.

Salinity on the surface generally increases from southwest to northeast. In winter and spring it is 4 -5°/00 near the mouths of the Kolyma and Indigirka, reaches values of 24-26°/00 near the Bear Islands, increases to 28-30°/00 in central regions sea and rises to 31-32 ° / 00 on its northern outskirts. In summer, as a result of the inflow of river waters and the melting of ice, the surface salinity decreases to 18-22°/00 in the coastal zone, 20-22°/00 near the Bear Islands, to 24 - 26 ° / 00 in the north, at the edge of melting ice.

In winter, in most of the sea, salinity slightly increases from the surface to the bottom. Only in the northwestern region, where ocean waters penetrate from the north, salinity increases from 23°/00 in the upper layer 10-15 m thick to 30°/00 near the bottom. Near the mouth areas, the upper desalinated layer up to horizons of 10-15 m is underlain by more saline waters. From the end of spring and during summer, a desalinated layer 20–25 m thick forms on ice-free spaces, under which salinity increases with depth. Consequently, in shallow areas (down to depths of 10-20 and even up to 25 m), freshening covers the entire water column. In deeper areas in the north and east of the sea, at horizons of 5-10 m, and in some places 10-15 m, salinity increases sharply, and then gradually and slightly rises to the bottom.

In the autumn-winter season, the density of water is higher than in spring and summer. The density is greater in the north and east than in the west of the sea, where desalinated waters from the Laptev Sea penetrate. However, these differences are small. Generally density increases with depth. Its vertical distribution is similar to the course of salinity.

The different degree of interstratification of waters creates unequal conditions for the development of mixing in different areas East Siberian Sea. On relatively weakly stratified and ice-free spaces strong winds in summer, water is mixed up to horizons of 20-25 m. Consequently, in areas limited by a depth of 25 m, wind mixing extends to the bottom. In places of sharp stratification of waters in density, wind mixing penetrates only to horizons of 10-15 m, where it is limited by significant vertical density gradients.

Autumn-winter convection in the East Siberian Sea at depths of 40-50 m, which occupy more than 70% of its entire area, penetrates to the bottom. By the end of the cold season, the winter vertical circulation extends to horizons of 70-80 m, where it is limited by the great vertical stability of the waters.

2.5. Ice regime

The East Siberian Sea is the most arctic of the seas of the Soviet Arctic. From October - November to June - July it is completely covered with ice. At this time, the flow of ice from the Arctic Basin to the sea prevails, in contrast to other seas of the Arctic, where outward ice drift prevails. A characteristic feature of the ice of the East Siberian Sea is the significant development of fast ice in winter. At the same time, it is most widely distributed in the western, shallow part of the sea and occupies a narrow coastal strip in the east of the sea. In the west of the sea, the width of fast ice reaches 400-500 km. Here it joins the fast ice of the Laptev Sea. In the central regions its width is 250-300 km and to the east of Cape Shelagsky - 30-40 km. The fast ice boundary approximately coincides with the 25 km isobath, which runs 50 km north of the New Siberian Islands, then turns southeast, approaching the coast of the mainland near Cape Shelagsky. By the end of winter, the thickness of fast ice reaches 2 m. From west to east, the thickness of fast ice decreases. Drifting ice is located behind the fast ice. Usually this is one-year and two-year ice 2-3 m thick. In the very north of the sea, multi-year Arctic ice is found. The prevailing southerly winds in winter often carry drifting ice away from the northern edge of the fast ice. As a result, significant expanses of clear water and young ice appear, forming in the west the Novosibirsk and in the east the Zavrangelev stationary ice polynyas.

At the beginning of summer, after the breakup and destruction of fast ice, the position of the ice edge is determined by the action of winds and currents. However, ice is always found north of the band about. Wrangel - New Siberian Islands. In the western part of the sea, on the site of extensive fast ice, the Novosibirsk ice massif is being formed. It consists mainly of first-year ice and usually breaks up by the end of summer. The vast majority of space in the east of the sea is occupied by a spur of the Ayon oceanic ice massif, which largely forms heavy multi-year ice. Its southern periphery almost adjoins the coast of the mainland throughout the year, determining ice conditions in the sea.

2.6. Biology.

The flora and fauna of the East Siberian Sea are qualitatively poor compared to neighboring seas mainly due to severe ice conditions. However, in the areas of the mouths of the rivers, in addition to the omul, whitefish and grayling, there are large schools of white fish. (coregonidae). Other fish species have also been found there, which include polar smelt, navaga, polar cod, polar flounder and salmon fish: arctic char and nelma. Mammals are represented by walruses, seals and polar bears, birds - guillemots, sea gulls, cormorants. Cold-loving brackish-water forms are found in the central regions. Fishing is of local importance.

BIBLIOGRAPHY:

1. Bogdanov D.V. Oceans and seas on the eve of the XXI century. – M.: Nauka, 1991. – 128 p.

2. Sukhovey F.S. Seas of the oceans. - L.: Gidrometeoizdat, 1986. - 288 p.

3. Oceanographic Encyclopedia.- L.: Gidrometeoizdat, 1974. - 632 p.

4. Zalogin B. S., Kosarev A. N. Seas. - M.: Thought, 1999. - 400 p.

5. Nikiforov E. G., Shpayher A. O. Patterns of the formation of large-scale fluctuations in the hydrological regime of the Northern Arctic Ocean. - L .: Gidrometeoizdat, 1980. - 270 p.

He is called the most severe among all northern seas located on close distance from warm waters Atlantic Ocean. The East Siberian Sea, washing the northern coast of Russia in the East, with all its shallow water, literally freezes.

The sea, marginal to the Arctic Ocean, is located along northern shores Eastern Siberia between the New Siberian Islands and Wrangel Island, conditionally administrative shores belong to Yakutia and Chukotka autonomous region. Most of it is outlined by conditional lines, and only from the side adjacent to Russia, nature has created its own borders. The total area of the sea is quite large: 944,600 sq. km, provided that you cannot call it deep (the average is 54 m).

The borders are considered to be at the points of intersection of the meridian with the islands of Kotelny, Wrangel and capes Anisy, Blossom, Yakan and Svyatoy Nos. There are practically no islands here, the entire coastline is deeply cut into the land or protrudes from the sea and forms large bends, small meanders lead to the mouths of the rivers.

As for the nature of the coastline, the eastern one is not at all like the western one. So, in the area of the New Siberian Islands and the mouth of the Kolyma, there is a tundra dotted with swamps, the relief is quite gentle and low, but closer to the island of Ayon, the coast takes on a mountainous landscape. Almost low mounds approach the banks of the water, in some places abruptly breaking off.

The underwater relief is flat and uniform throughout the territory. Only in some areas there is a depth of up to 25 m. Experts call them the remains of ancient river valleys.

Often this sea is called an important site trade route, through which goods are transported to northern regions Eastern Siberia. Works here major port Pevek, he carries out transit movements from the West to the East of the country.

(Sea trade and transport port of Pevek)

The East Siberian Sea can hardly be called a fishing hub in Russia. For the most part, sea animals are harvested here in the waters adjacent to land. locals European smelt, capelin, cod and herring are caught here. Near the mouths of the rivers, valuable whitefish, sturgeon and salmon are caught. However, this type of activity does not make a serious economic contribution to the development of the country and the region.

Already from the name it is clear that this sea is located at north coast Eastern Siberia. The borders of the East Siberian Sea are mainly conditional lines, and only in some parts it is limited by land. From the west, the boundary of the sea runs along Kotelny Island and further along the eastern boundary of the Laptev Sea. The northern boundary coincides with the edge of the continental shelf. From the east, the boundary of the sea runs along the meridian of 1800 east longitude to Wrangel Island, after - along northwest coast this island to Cape Blossom and Cape Yakan, located on the mainland. From the southern part, the East Siberian Sea is limited by the coastline of the mainland (from Cape Yakan to Cape Svyatoy Nos).

Water this sea they communicate well with the waters of the Arctic Ocean, therefore the East Siberian Sea belongs to the type of continental marginal seas. Within the boundaries outlined, the area of this sea is 913 thousand km2. The volume of water is approximately equal to 49 thousand km3. The average depth of the sea is 54 m, maximum depth equal to 915 m.

There are very few islands in the waters of the East Siberian Sea. The coastline of the sea has large bends. Thus, in some places the sea pushes the boundaries of the land inland, and in some places the land protrudes into the sea. There are also areas with almost flat coastline. Small meanders are formed mainly in the mouths of rivers. The relief of the western and east coasts The East Siberian Sea is very different. The coast, which washes the sea from the New Siberian Islands to the mouth of the Kolyma, has a fairly monotonous landscape. Here the sea borders on areas of swampy tundra. These places are characterized by low and gently sloping shores. The coast, located east of Kalyma, has a more diverse landscape, mostly mountains prevail here. As far as the island of Aion, the sea is bordered by small hills, which sometimes have steep slopes. In the area of the Chaun Bay there are low but steep banks.

The underwater relief of the space occupied by the East Siberian Sea is a plain. This plain has a slight slope from the southwest to the northeast. The bottom of the sea is predominantly flat, without significant depressions and elevations. Most of the water expanses of the East Siberian Sea have a depth of up to 20 - 25 m. The deepest trenches are located on the sea bottom in the northeastern part of the mouths of the Indigira and Kolyma rivers. There is an assumption that these trenches used to be areas of river valleys. But later these rivers were flooded with the sea. The western part of the sea is characterized by a shallow depth; this area is called the Novosibirsk Shoal. In the northeast, the seas are quite deep places. But even here the depth does not exceed 100 m.

East-Siberian Sea

The East Siberian Sea is located in high latitudes, not far from permanent ice Arctic Ocean. The sea also borders on a wide part of the mainland. In connection with this location, the climate of the East Siberian Sea has distinguishing feature: the sea is under the influence of the Atlantic and Pacific oceans. In the western part of the sea, cyclones sometimes form over by the atlantic sea. The eastern regions of the sea are accessible to cyclones of Pacific origin. Thus, the climate of the East Siberian Sea can be characterized as polar maritime, which is affected by big influence continent. The peculiarity of the continental climate is significantly manifested in winter and summer. During the transitional seasons, they do not significantly affect, since during these periods the atmospheric processes are unstable.

IN winter time has a great influence on the climate of the East Siberian Sea Siberian maximum. This causes the predominance of southwestern and southern winds, the speed of which reaches 6 - 7 m/s. These winds move from the continent and therefore contribute to the spread of cold air. average temperature in January is approximately - 28 - 300C. In winter, the weather is mostly clear. Only sometimes cyclones break the settled calm weather for several days. Atlantic cyclones, which prevail in the western part of the sea, contribute to increased wind and temperature rise. Pacific cyclones, which dominate the southeastern part of the sea, bring strong winds, snowstorms and cloudy weather. On the coasts with a mountainous landscape, the Pacific cyclone contributes to the formation of a strong wind - foehn. As a result of this storm wind, the temperature rises, while the humidity of the air becomes less.

In summer, high pressure zones form over the sea, and low pressure zones over land. In this regard, the winds blow mainly from the north. At the beginning of the warm season, the winds are not yet gaining sufficient strength, but by the middle of summer their average speed is 6-7 m/s. By the end of summer, the western part of the sea turns into zones of strong storms. At this time, this section becomes the most dangerous along the entire route of the Northern Sea Route. Very often the wind speed reaches 10 - 15 m/s. Such strong winds are not observed in the southeastern part of the sea. The wind speed here can only increase in connection with the hair dryers. Constant winds of northern and northeastern directions contribute to the preservation of low air temperatures. In the northern part of the sea, the average July temperature is about 0 - +10C, in coastal areas the temperature is slightly higher than +2 - 30C. The decrease in temperature in the northern part of the sea is affected by the influence of Arctic ice. In the southern part of the sea, proximity to a warm mainland contributes to an increase in temperature. Cloudy weather is typical for the East Siberian Sea in summer. Very often there are light rains, and occasionally even sleet.

East-Siberian Sea

In autumn, the influence of the Pacific and Atlantic Oceans weakens, resulting in a decrease in air temperature. Thus, the East Siberian Sea is characterized by a cold summer; unstable windy weather in the western and eastern regions of the sea in the summer-autumn period and calm in the central territories.

A small amount of river water enters the East Siberian Sea. During the year, the volume of continental runoff is approximately 250 km3. Kolyma (most big river flowing into this sea) brings about 132 km3 per year. Another large river Indigirka gives 59 km3. The rest of the rivers flowing into the East Siberian Sea are small, so they discharge a small amount of water. The largest number fresh water enters southern part seas. The maximum flow occurs in the summer. Due to the small amount fresh water does not enter far into the sea, but mainly spreads near the mouths of rivers. Due to the fact that the East Siberian Sea has big sizes, river runoff does not have a significant effect on it.

The waters of the East Siberian Sea are relatively clean. Only in the bay of Pevek, slight water pollution has been noted, but recently the ecological situation has been improving here. The waters of the Chaun Bay are slightly polluted with petroleum hydrocarbons.

Due to the harsh climate, life has developed in the East Siberian Sea. Only the most persistent representatives of flora and fauna live here, which have adapted to low temperatures. In its waters, there are the same microscopic algae and organisms that are found in the neighboring Laptev Sea. Mostly diatoms are found, from time to time red and brown algae appear - in the coastal region of the western part of the sea. Compared to neighboring seas, there are few bottom dwellers here. After all, not every species can survive in conditions of low temperatures. Therefore, there are only some types of crustaceans, valvular, echinoderm and intestinal mollusks.

Among the mammals of the East Siberian Sea: seals, beluga whales, cetaceans and walruses. Along with all the coastal zones of the northern seas, walruses are harvested on its territory, but only for the needs local population. Indeed, since 1956, walruses have been under state protection. Also living on the islands polar bear, which is a semi-marine mammal. For the sake of food, smaller predators come to the shores of the East Siberian Sea, we are talking about sea otters and arctic foxes.

There is no information that sharks live in the waters of this sea. Perhaps here you can meet a polar shark - an inhabitant of the Arctic waters. Such a six-meter shark almost never comes to the sea surface. It feeds on the smallest organisms, animal remains and small fish. The polar shark is lazy, like many other arctic giants, so do not expect an attack on active animals. Scientists say that the bathers of this harsh sea may not be afraid of the teeth of man-eating sharks. Therefore, travelers can often be found here.

Off the coast of the East Siberian Sea

The East Siberian Sea is located between the New Siberian Islands and about. Wrangel. Its western border is the eastern border of the Laptev Sea, it runs from the point of intersection of the meridian of the northern tip of about. Boiler house with the edge of the continental shoal (79°N, 139°E) to the northern tip of this island (Cape Anisii), then along the eastern shores of the New Siberian Islands to Cape Svyatoy Nos (Dmitry Laptev Strait). The northern boundary runs along the edge of the continental shelf from the point with coordinates 79°N, 139°E. to the point with coordinates 76°N, 180°E, and the eastern border - from the point with these coordinates along the meridian 180° to about. Wrangel, then along its northwestern coast to Cape Blossom and further to Cape Yakan on the mainland. The southern border runs along the mainland coast from Cape Yakan to Cape Svyatoy Nos.

The East Siberian Sea belongs to the type of continental marginal seas. Its area is 913 thousand km 2, its volume is 49 thousand km 3, the average depth is 54 m, the greatest depth is 915 m, i.e. this sea lies entirely on the continental shelf.

The landscapes of the western part of the coast of the East Siberian Sea differ sharply from the eastern part. In the section from the New Siberian Islands to the mouth of the Kolyma, the coasts are very low and monotonous. Here the swampy tundra approaches the sea. To the east of the mouth of the Kolyma, beyond Cape Bolshoy Baranov, the coast becomes mountainous. From the mouth of the Kolyma to about. Aion directly to the water approach low hills, abruptly breaking off in some places. The Chaun Bay is framed by low, but steep, even banks. Different in relief and structure, the coast of the sea in different areas refers to different morphological types of coasts.

East-Siberian Sea

Climate

Located in high latitudes, the East Siberian Sea is located in the zone of atmospheric influences of the Atlantic and Pacific oceans. Cyclones of Atlantic origin (although rarely) penetrate into the western part of the sea, and Pacific cyclones penetrate into the eastern regions. The climate of the East Siberian Sea is polar maritime, but with signs of continentality.

In winter, the main influence on the sea is exerted by the spur of the Siberian High, which goes to the coast, and the crest of the polar anticyclone is weakly expressed. In this regard, south-westerly and southerly winds prevail over the sea at a speed of 6-7 m/s. They bring cold air from the continent, so the average monthly air temperature in January is about -28-30°. In winter, there is calm, clear weather, which on some days is disturbed by cyclonic intrusions. Atlantic cyclones in the west of the sea cause increased winds and some warming, while Pacific cyclones, which have cold continental air in the rear, only increase wind speed, cloudiness and cause snowstorms in the southeastern part of the sea. In mountainous areas of the coast, the passage of Pacific cyclones is associated with the formation of a local wind - foehn. It usually reaches storm strength, causing some increase in temperature and a decrease in air humidity.

In summer, the pressure over the mainland of Asia is lowered, and over the sea it is increased, so the northerly winds prevail. At the beginning of the season they are very weak, but during the summer their speed gradually increases, reaching an average of 6-7 m/s. By the end of summer, the western part of the East Siberian Sea becomes one of the most turbulent sections of the Northern Sea Route. Often the wind blows at a speed of 10-15 m/s. The strengthening of the wind here is associated with hair dryers. The southeastern part of the sea is much calmer. Steady north and northeast winds cause low air temperatures. The average July temperature is 0-1° in the north of the sea and 2-3° in coastal areas. In the summer, the weather over the East Siberian Sea is predominantly cloudy with light drizzle, sometimes it snows.

The continental runoff into the East Siberian Sea is relatively small - about 250 km 3 /year, which is only 10% of the total river runoff into all the Arctic seas. The largest of the flowing rivers - Kolyma - gives about 130 km 3 of water per year, and the second largest river - Indigirka - 60 km 3 of water / year. All other rivers pour about 350 km 3 of water into the sea during the same time. All river water enters the southern part of the sea, and approximately 90% of the runoff falls, as in other Arctic seas, during the summer months.

With a very large size of the East Siberian Sea, coastal runoff does not significantly affect its general hydrological regime, but only causes some hydrological features coastal areas in the summer. High latitudes, free communication with the Central Arctic Basin, high ice coverage and low river flow determine the main features of the hydrological conditions of the East Siberian Sea.

Water temperature and salinity

Types of vertical distribution of temperature (1), salinity (2) and density (3) of water in the Arctic seas

Surface water temperatures generally decrease from south to north in all seasons. In winter, it is close to the freezing point and near the mouths of the rivers it is -0.2-0.6°, and at the northern borders of the sea -1.7-1.8°. In summer, the distribution of surface temperature is determined by the ice conditions. The water temperature in bays and bays reaches 7-8°, in open, ice-free areas 2-3°, and near the ice edge it is close to 0°.

The change in water temperature with depth in winter and spring is hardly noticeable. Only near the mouths of large rivers does it decrease to -0.5° in the subglacial horizons and to -1.5° near the bottom. In summer, in ice-free spaces, the water temperature drops slightly from the surface to the bottom in the coastal zone in the west of the sea. In its eastern part, surface temperature is observed in the 3-5 m layer, from where it drops sharply to 5-7 m horizons and then gradually decreases to the bottom. In the zones of influence of coastal runoff, a uniform temperature covers a layer up to 7-10 m, between horizons of 10-20 m it sharply, and then gradually decreases to the bottom. The shallow, slightly warm East Siberian Sea is one of the coldest Arctic seas.

Surface salinity generally increases from southwest to northeast. In winter and spring, it is 4–5‰ near the mouths of the Kolyma and Indigirka, reaches 24–26‰ near the Bear Islands, increases to 28–30‰ in the central regions of the sea, and rises to 31–32‰ at its northern margins. In summer, as a result of the inflow of river waters and the melting of ice, the surface salinity decreases to 18-22‰ in the coastal zone, 20-22‰ near the Bear Islands, to 24-26‰ in the north, at the edge of the melting ice.

In winter, in most of the sea, salinity slightly increases from the surface to the bottom. Only in the northwestern region, where they penetrate ocean waters from the north, salinity increases from 23‰ in the upper layer 10-15 m thick to 30‰ at the bottom. Near the mouth areas, the upper desalinated layer up to horizons of 10-15 m is underlain by more saline waters. From the end of spring and during summer, a desalinated layer 20–25 m thick forms on ice-free spaces, under which salinity increases with depth. Consequently, in shallow areas (down to depths of 10-20 and even up to 25 m), freshening covers the entire water column. In deeper areas in the north and east of the sea, at horizons of 5-10 m, and in some places 10-15 m, salinity increases sharply, and then gradually and slightly rises to the bottom.

The different degree of water overstratification creates different conditions for the development of mixing in different areas of the East Siberian Sea. In relatively weakly stratified and ice-free spaces, strong winds in summer mix water up to 20-25 m horizons. Consequently, in areas limited by a depth of 25 m, wind mixing extends to the bottom. In places of sharp stratification of waters in density, wind mixing penetrates only to horizons of 10-15 m, where it is limited by significant vertical density gradients.

Bottom relief

The underwater relief of the shelf that forms the bed of the sea, in general terms, is a plain, very slightly inclined from the southwest to the northeast. The bottom of the sea has no noticeable depressions and hills. Depths up to 20-25 m prevail. To the northeast of the mouths of the Indigirka and Kolyma, shallow trenches are noted on the seabed. It is believed that these are traces of ancient river valleys flooded by the sea. The area of shallow depths in the western part of the sea forms the Novosibirsk shoal. The greatest depths are concentrated in the northeastern part of the sea. A noticeable increase in depth occurs in the horizon from 100 to 200 m.

Bottom relief and currents of the East Siberian Sea

currents

Constant currents on the surface of the East Siberian Sea form a weakly expressed cyclonic circulation. Along the mainland coast, there is a steady transfer of water from west to east. At Cape Billing, part of the waters is directed to the north and northwest and carried to the northern margins of the sea, where it is included in the streams going to the west. In different synoptic situations, the movement of waters also changes. Part of the water from the East Siberian Sea through the Long Strait is carried to the Chukchi Sea. Permanent currents are often disturbed by wind currents, which are often stronger than permanent currents. The influence of tidal currents is relatively small.

Regular semidiurnal tides are observed in the East Siberian Sea. They are caused by a tidal wave that enters the sea from the north and moves towards the coast of the mainland. Its front is stretched from the north-north-west to the east-south-east from the New Siberian Islands to about. Wrangel.

The annual course of the level is characterized by its highest position in June-July, when there is an abundant inflow of river waters. The decrease in continental runoff in August leads to a decrease in the level by 50-70 cm. As a result of the predominance of surge winds in autumn, in October, the level rises.

In winter, the level drops and in March - April reaches its lowest position.

Rapid and abrupt change in level positions is one of the characteristic features coastal areas seas.

Significant waves develop in the ice-free areas of the sea. It is strongest during stormy northwestern and southeastern winds, which have the largest accelerations over the surface of clear water. The maximum wave heights reach 5 m, usually their height is 3-4 m. Strong waves are observed mainly in late summer - early autumn (September), when the ice edge recedes to the north. The western part of the sea is more stormy than the eastern one. Its central regions are relatively calm.

ice coverage

The East Siberian Sea is the most arctic of the seas of the Soviet Arctic. From October-November to June-July it is completely covered with ice. At this time, the flow of ice from the Arctic Basin to the sea prevails, in contrast to other seas of the Arctic, where outward ice drift prevails. A characteristic feature of the ice of the East Siberian Sea is the significant development of fast ice in winter. At the same time, it is most widely distributed in the western, shallow part of the sea and occupies a narrow coastal strip in the east of the sea. In the west of the sea, the width of fast ice reaches 400-500 km. Here it joins the fast ice of the Laptev Sea. In the central regions its width is 250-300 km and to the east of Cape Shelagsky - 30-40 km. The fast ice boundary approximately coincides with the 25 km isobath, which runs 50 km north of the New Siberian Islands, then turns southeast, approaching the coast of the mainland near Cape Shelagsky. By the end of winter, the thickness of fast ice reaches 2 m. From west to east, the thickness of fast ice decreases. Drifting ice is located behind the fast ice. Usually this is one-year and two-year ice 2-3 m thick. In the very north of the sea, multi-year Arctic ice is found. The prevailing southerly winds in winter often carry drifting ice away from the northern edge of the fast ice. As a result of this, significant expanses of clear water and young ice appear, forming in the west the Novosibirsk and in the east the Zavrangel stationary ice polynyas.

At the beginning of summer, after the breakup and destruction of fast ice, the position of the ice edge is determined by the action of winds and currents. However, ice is always found north of the band about. Wrangel - New Siberian Islands. In the western part of the sea, on the site of extensive fast ice, the Novosibirsk ice massif is being formed. It consists mainly of first-year ice and usually breaks up by the end of summer. The vast majority of space in the east of the sea is occupied by the spur of the Ayon oceanic ice massif, which largely forms heavy perennial ice. Its southern periphery during the whole year almost adjoins the coast of the mainland, determining the ice situation in the sea.

Economic importance

The East Siberian Sea is similar in natural and biological conditions to the Laptev Sea. The relative richness of life is observed in the coastal zone, in the areas where large rivers flow. Animals adapted to life in waters with low salinity are common here. Cold-loving brackish-water forms are found in the central regions. Fishing is purely local.