East Siberian Sea fauna. East Siberian Sea: description, resources and problems. Water temperature and salinity

The East Siberian Sea belongs to the Arctic Ocean. It is bounded on the west by the New Siberian Islands, and on the east by Wrangel Island. This body of water is the least studied compared to other northern seas. These places are characterized by a cold climate with poor flora and fauna and low salinity sea water.

Sea currents are slow, tides reach no more than 25 cm. In summer there is frequent fog, ice lasts almost all year round, it retreats only in August-September. sea coast was inhabited thousands of years ago by the Chukchi and Yukagirs, and then by the Evenks and Evens. These peoples were engaged in hunting, fishing and reindeer herding. Later the Yakuts appeared, and then the Russians.

East Siberian Sea on the map

Geography

Water surface area East Siberian Sea is 942 thousand sq. km. The volume of water reaches 60.7 thousand cubic meters. km. The average depth is 45 meters, and the maximum is 155 meters. The length of the coastline is 3016 km. The western border of the reservoir passes through the New Siberian Islands. The northernmost of them is Henrietta Island, part of the De Long Islands group.

The eastern border passes through Wrangel Island and Long Strait. In the north from the northernmost point of Wrangel to Henrietta, Zhannetta Island and further to the northern point of Kotelny Island. The southern border runs along the coast of the mainland from Cape Svyatoy Nos in the west to Cape Yakan in the east. The reservoir is connected to the Laptev Sea through the Sannikov, Eterikan and Dmitry Laptev straits. And the connection with the Chukchi Sea is through the Long Strait.

Rivers and bays

The most important rivers flowing into the reservoir are Indigirka with a length of 1726 km, Kolyma with a length of 2129 km, Chaun with a length of 205 km, Pegtymel with a length of 345 km, Bolshaya Chukochia with a length of 758 km, Alazeya with a length of 1590 km.

On the coast there are such bays as Chaunskaya Bay, Omulyakhskaya Bay, Gusinaya Bay, Khromskaya Bay, Kolyma Bay. All these bays flow deep into the land. There is also the Kolyma Bay, bounded from the north by the Bear Islands: Krestovsky, Pushkareva, Leontiev, Lysova, Andreeva and Chetyrekhstolbovaya.

The river flow is small and amounts to 250 cubic meters. km per year. Of these, the Kolyma River produces 132 cubic meters. km of water. Indigirka discharges 59 cubic meters into the East Siberian Sea. km of water. 90% of the total runoff occurs in the summer. Fresh water is concentrated near the shore due to weak currents and does not have a significant effect on the hydrology of the reservoir. But there is water exchange with neighboring seas and the Arctic Ocean.

The water surface temperature decreases from south to north. In winter in river deltas it is -0.2 and -0.6 degrees Celsius. And in the northern part of the sea it drops to -1.8 degrees Celsius. In summer, the water in the bays warms up to 7-8 degrees Celsius, and in ice-free sea areas it is 2-3 degrees Celsius.

The salinity of surface waters increases from southwest to northeast. In the area of river deltas in winter and spring it is 4-5 ppm. In open waters it reaches 28-30 ppm, and in the north up to 31-32 ppm. In summer, salinity decreases by 5% due to snow melting.

The annual fluctuation in the level of the East Siberian Sea is 70 cm due to summer river flows. The winds bring storms with waves 3-5 meters high in the western part of the sea region, while in the east it is relatively calm. Storms usually last 1-2 days in summer and 3-5 days in winter.

The ice thickness reaches 2 meters by the end of winter and decreases from west to east. In addition, there are drifting ice floes with a thickness of 2-3 meters. Ice melting begins in May from the Kolyma River delta. And the reservoir completely freezes in October-November.

Climate

The climate is arctic. In winter the wind blows from the southwest and southerly winds, carrying cold air from Siberia, therefore average temperature in winter it is -30 degrees Celsius. The weather is cloudy with storms and snowstorms.

They blow in summer north winds, and the air temperature is 0-1 degrees Celsius in the open sea and 2-3 degrees Celsius on the coast. The sky is cloudy with frequent rain and sleet. The shores are covered in fog; it can last up to 70 days. The annual precipitation is 200 mm.

Flora and fauna are sparse due to the harsh climate. There is a lot of plankton and crustaceans in the water. Ringed seals, bearded seals, walruses, and polar bears live in coastal areas. Birds include seagulls and cormorants. The East Siberian Sea is frequently visited by bowhead and gray whales. There are belugas and narwhals. Among the fish there are grayling, muksun, whitefish, smelt, cod, arctic char, navaga, and flounder.

Shipping

Shipping is practiced to transport goods along north coast Russia in August-September. At the same time, navigation is difficult even in summer due to floating ice floes that are carried to the shores by the wind. Fishing and hunting of marine animals is local in nature.

The main port is Pevek with a population of about 5 thousand people. He is the most northern city Russia and is located in Chaunskaya Bay. Freight turnover seaport is 190 thousand tons at bandwidth 330 thousand tons. There are 3 berths with a length of 500 meters. Cargo transportation is carried out mainly between Pevek and Vladivostok.

The reservoir received its modern name in June 1935 in accordance with the decree of the Soviet government. Before that, it was called either the Indigirsky Sea, or the Northern Sea, or the Kolyma Sea, or the Siberian Sea, or the Arctic Sea.

Off the coast of the East Siberian Sea

The East Siberian Sea is located between the New Siberian Islands and the island. Wrangel. Its western border is eastern border Laptev Sea, it runs from the point of intersection of the meridian of the northern tip of the island. Kotelny with the edge of the mainland shallows (79° N, 139° E) to the northern tip of this island (Cape Anisiy), then along the eastern shores of the New Siberian Islands to Cape Svyatoy Nos (Dmitry Laptev Strait). The northern border runs along the edge of the continental shelf from a 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 the island. Wrangel, then along its northwestern shore 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, average depth- 54 m, greatest depth - 915 m, i.e. this sea lies entirely on the continental shallows.

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

The landscapes of the western part of the coast of the East Siberian Sea are sharply different from the eastern. In the area from the New Siberian Islands to the mouth of the Kolyma, the banks are very low-lying and monotonous. Here the swampy tundra approaches the sea. East of the mouth of the Kolyma, beyond Cape Bolshoi Baranov, the coast becomes mountainous. From the mouth of Kolyma to about. Ayon, low hills approach the water directly, and in some places they drop steeply. Chaunskaya Bay is framed by low but steep, flat banks. The sea coast, which differs in relief and structure in different areas, belongs to different morphological types of coasts.

East-Siberian Sea

Climate

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

In winter, the main influence on the sea is exerted by the spur of the Siberian High, which extends to the coast, and the crest of the polar anticyclone is weakly expressed. In this regard, southwestern and southern winds prevail over the sea at a speed of 6-7 m/s. They bring cold air from the continent, so average monthly temperature The air in January is about –28-30°. In winter there is calm, clear weather, which on some days is disrupted by cyclonic incursions. Atlantic cyclones in the west of the sea cause increased wind and some warming, and 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. On mountainous areas of the coast, the passage of Pacific cyclones is associated with the formation of a local wind - a foehn. It usually reaches storm force, causing a slight increase in temperature and a decrease in air humidity.

In summer, the pressure over the mainland of Asia is reduced, and over the sea it is increased, so winds from the northern directions predominate. 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 West Side The East Siberian Sea is becoming one of the most stormy sections of the Northern Sea Route. The wind often blows at a speed of 10-15 m/s. The increase in wind here is due to hair dryers. The southeastern part of the sea is much calmer. Steady northern and northeastern 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 summer time over the East Siberian Sea the weather is mostly cloudy with light drizzling rain, and sometimes there is sleet.

Continental flow into the East Siberian Sea is relatively small - about 250 km 3 /year, which is only 10% of the total river flow into all Arctic seas. The largest of the inflowing rivers, the Kolyma, produces about 130 km 3 of water per year, and the second largest river, the Indigirka, produces 60 km 3 of water per year. During the same time, all other rivers pour approximately 350 km 3 of water into the sea. All river water flows into southern part seas, and approximately 90% of the runoff occurs, as in other Arctic seas, in 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 the summer. High latitudes, free communication with the Central Arctic Basin, large ice cover 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

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

The surface water temperature in all seasons generally decreases from south to north. In winter it is close to the freezing point and near river mouths 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 ice conditions. The water temperature in bays and bays reaches 7-8°, in open, ice-free areas 2-3°, and at the ice edge it is close to 0°.

The change in water temperature with depth in winter and spring is little noticeable. Only near the mouths large rivers it decreases to –0.5° in subglacial horizons and to –1.5° at the bottom. In summer, in ice-free areas, the water temperature decreases slightly from the surface to the bottom in the coastal zone in the west of the sea. In its eastern part, the surface temperature is observed in a layer of 3-5 m, from where it sharply drops to horizons of 5-7 m and then gradually decreases towards the bottom. In zones of influence of coastal runoff, a uniform temperature covers a layer of up to 7-10 m, between horizons of 10-20 m it sharply, and then gradually decreases to the bottom. The shallow, weakly warmed 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 Medvezhye Islands, increases to 28-30‰ in the central regions of the sea and rises to 31-32‰ on its northern outskirts. In summer, as a result of the influx river waters and melting 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, over most of the sea, salinity increases slightly 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 to horizons of 10-15 m is underlain by more saline waters. From the end of spring and during the summer, a desalinated layer 20-25 m thick forms in ice-free areas, under which the salinity increases with depth. Consequently, in shallow areas (down to depths of 10-20 and even up to 25 m), desalination 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, the 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. Typically, density increases with depth. Its vertical distribution is similar to the course of salinity.

Different degrees of interlayering of waters create different conditions for the development of mixing in different areas of the East Siberian Sea. In relatively weakly stratified and ice-free areas, strong winds in summer mix water to horizons of 20-25 m. Consequently, in areas limited to a depth of 25 m, wind mixing extends to the bottom. In places where waters are sharply stratified by 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 total 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 greater vertical stability of the waters.

Bottom relief

The underwater relief of the shelf that forms the bed of the sea is, in general terms, a plain, very slightly inclined from southwest to northeast. The seabed has no noticeable depressions or hills. The predominant depths are up to 20-25 m. Northeast of the mouths of the Indigirka and Kolyma on seabed Shallow gutters are noted. 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 topography 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 continental coast there is a steady transport of water from west to east. At Cape Billinga, part of the waters are directed to the north and northwest and are carried to the northern outskirts of the sea, where they are included in the flows going to the west. Under different weather conditions, the movement of water also changes. Part of the water from the East Siberian Sea is carried through the Long Strait into the Chukchi Sea. Constant currents are often disturbed by wind currents, which are often stronger than constant ones. 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 extends from the north-northwest to the east-southeast from the New Siberian Islands to the island. 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 waters. Thus, in the area from Indigirka to Cape Shelagskoye, 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 continental coast.

The annual variation of the level is characterized by its highest position in June-July, when there is an abundant influx of river water. A reduction in continental runoff in August leads to a drop in level by 50-70 cm. As a result of the predominance of surge winds in the fall, in October, the level rises.

In winter, the level decreases and reaches its lowest point in March - April.

IN 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 the maximum values for the entire sea - 2.5 m.

A quick and abrupt change in level positions is one of the characteristic features coastal areas of the sea.

Significant waves develop in ice-free areas of the sea. It is strongest during stormy northwestern and southeastern winds, which have the highest accelerations above the surface clean water. 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 retreats to the north. The western part of the sea is rougher than the eastern. Its central areas are relatively calm.

Ice cover

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 transport of ice from the Arctic basin to the sea predominates, in contrast to other Arctic seas, where outflow ice drift prevails. A characteristic feature of the ice of the East Siberian Sea is the significant development of fast ice in winter. Moreover, 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 connects with the fast ice of the Laptev Sea. In the central regions its width is 250-300 km and 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 to the southeast, approaching the coast of the mainland at Cape Shelagsky. By the end of winter, the thickness of the fast ice reaches 2 m. From west to east, the thickness of the fast ice decreases. Behind the fast ice there is drifting 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 winds from the south in winter often carry drifting ice away from the northern edge of the fast ice. As a result, significant expanses of clean water and young ice appear, forming the Novosibirsk stationary french polynyas in the west and Zavrangelevskaya in the east.

At the beginning of summer, after the opening 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 island. Wrangel - New Siberian Islands. In the western part of the sea, on the site of extensive fast ice, the Novosibirsk ice massif is formed. It consists mainly of first-year ice and usually collapses by the end of summer. The overwhelming majority of the space in the east of the sea is occupied by the spur of the Aion oceanic ice massif, which largely forms heavy multi-year ice. Its southern periphery is almost adjacent to the coast of the mainland throughout the year, determining the ice situation in the sea.

Economic importance

The East Siberian Sea is similar in natural and biological conditions to the Laptev Sea. A relative abundance 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 has a clean local significance.

EAST SIBERIAN SEA, marginal sea of the Arctic Ocean near the north eastern shores Asia, between the New Siberian Islands and Wrangel Island. In the west it borders on the Laptev Sea, connecting with it through the Dmitry Laptev, Eterikan and Sannikov straits, in the east - on the Chukchi Sea, with which it is connected by the Long Strait. The northern border runs along the edge of the continental shelf, approximately along an isobath of 200 m (79° north latitude). Area 913 thousand km 2, volume 49 thousand km 3. The greatest depth is 915 m.

The coastline is relatively weakly indented. Bays: Chaunskaya Bay, Kolyma Bay, Omulyakhskaya and Khromskaya Bays. Islands: Novosibirsk, Bear, Aion and Shalaurov. Some islands are composed entirely of fossil ice and sand and are subject to intense destruction. Large rivers flow into the sea: Kolyma, Alazeya, Indigirka, Khroma. The coast of the western part of the sea (up to the Kolyma River) is low-lying and composed of permafrost alluvial-marine sediments of Quaternary age, including lenses of fossil ice. East Coast(from the Kolyma River to the Long Strait) mountainous, steep in places, composed of bedrock; A denudation type of coastline is developed here.

Relief and geological structure bottom. The East Siberian Sea is located mainly within the shelf; 72% of its bottom area has depths of up to 50 m. The shelf is located within the North American lithospheric plate. The underwater relief of the shelf, which forms the bed of the sea, is a plain, slightly inclined from southwest to northeast. The bottom of the western part of the sea is a flat, shallow plain, where the Novosibirsk Shoal is located. In the southern part, shallow troughs are noted - traces of ancient river valleys of pre-glacial and glacial times. The greatest depths are in the northeastern part. The seabed is composed of folded complexes (Mesozoic in the south and, possibly, more ancient in the north), dissected by Late Mesozoic rift structures and covered by a thin cover of Cenozoic sediments. Modern bottom sediments consist mainly of sandy silt containing crushed boulders and pebbles carried by ice.

Climate. The climate of the East Siberian Sea is arctic. In winter, under the influence of the Siberian High, cold southwestern and southern winds prevail over the sea. Average air temperatures in February range from -28 to -30 °C (minimum -50 °C); in July in the southern part from 3 to 7 °C, in the northern part - from 0 to 2 °C. In summer, the weather over the East Siberian Sea is mostly cloudy with light drizzle and sometimes sleet; Northerly winds predominate. In autumn, on the coast, the speed of northwestern and northeastern winds increases to 20-25 m/s; At a distance from the coast, the strength of storm winds reaches 40-45 m/s, and hair dryers contribute to the intensification of the wind. 100-200 mm of precipitation falls annually.

Hydrological regime. Continental flow into the East Siberian Sea is relatively small and amounts to about 250 km 3 /year, of which the flow of Kolyma is 123 km 3 /year, Indigirka is 58.3 km 3 /year. The entire river flow flows into the southern part of the sea, 90% in the summer. The main part of the East Siberian Sea is occupied by surface Arctic waters. In the estuarine areas, waters formed as a result of mixing river and sea water are common. In winter, near river mouths, the surface water temperature varies from -0.2 to -0.6 °C, and at the northern border of the sea from -1.7 to -1.8 °C. In summer, the temperature distribution of surface waters is determined by ice conditions. In bays and bays it is 7-8 °C, in ice-free areas it is 2-3 °C, and at the ice edge it is about 0 °C. The salinity of surface waters increases from southwest to northeast from 10-15‰ near river mouths to 30-32‰ at the ice edge. For most of the year, the East Siberian Sea is covered with ice. In the eastern part floating ice remain off the coast even in summer. A characteristic feature of the ice is the development of fast ice, which is most widely distributed in the western shallow part of the sea, where its width reaches 600-700 km; in the central regions - 250-300 km, east of Cape Shelagsky it occupies a narrow coastal strip of 30-40 km. By the end of summer, the thickness of the fast ice is 2 m. Behind the fast ice there is drifting ice - annual and biennial ice, 2-3 m thick; Ice drift depends on the circulation of air masses. In the north there is multi-year Arctic ice. In the western part of the sea, between fast ice and drifting ice, there is a perennial polynya through which the Northern Sea Route passes. The existence of the polynya in winter is associated with squeezing winds and tidal currents. In the eastern part, the fast ice meets the drifting ice and the polynya closes. The currents form a cyclonic gyre; in the northern part the current is directed to the west, in the southern part - to the east. The tides are regular semidiurnal, the amplitude of level fluctuations is up to 25 cm.

History of the study. The beginning of the development of the East Siberian Sea by Russian sailors dates back to the 17th century, when voyages were made along the coast between river mouths on Kochs. In 1648, S. Dezhnev and F. Popov sailed from the Kolyma River to the Bering Strait and to the Anadyr River. In the 18th century, the first works were carried out to describe the coast and islands of the East Siberian Sea, and maps were compiled. Particularly significant work was done by the participants of the Great Northern Expedition (1733-43). The contours of the coast were clarified by the Ust-Yansk and Kolyma expeditions led by P. F. Anzhu (1822) and F. P. Wrangel (1820-24), islands in the East Siberian Sea were named after them. In the 20th century, maps were updated by K. A. Vollosovich (1909) and G. Ya. Sedov (1909), as well as during the work of a hydrographic expedition in the Arctic Ocean (1911-14). After 1932, when the icebreaker Sibiryakov passed the Northern Sea Route in one navigation, regular ship voyages were made to the East Siberian Sea.

Economic use. The coastal zone is characterized as an area with weak economic activity. Vegetable and animal world The East Siberian Sea is poor due to harsh ice conditions. But in the areas adjacent to the river mouths, you can find omul, whitefish, grayling, polar smelt, navaga, polar cod and flounder, salmonids - char and nelma. Mammals include walrus, seals, polar bear; of birds - guillemots, gulls, cormorants. Fishing is of local importance. The Northern Sea Route passes through the East Siberian Sea; main port Pevek (Chaun Bay). The East Siberian Sea is a promising oil and gas bearing area, the development of which is difficult due to harsh natural conditions.

Ecological state. In general, the ecological situation in the East Siberian Sea is characterized as favorable due to the weak economic use of this area. The shallow-water shelf, exposed to the influence of river runoff, is slightly polluted, and as a result of thermal abrasion destruction of the coast, greenhouse gases (carbon dioxide and methane) enter the atmosphere.

Lit.: Zalogin B.S., Kosarev A.N. Seas. M., 1999.

November 26, 2006

1. NORTH ARCTIC OCEAN…………………………………………………………….3

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

2.1. Shores…………………………………………………………………………………5

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. NORTH 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). Nevertheless, the practical and scientific significance of research in the Arctic Ocean is very great. 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 rapidly developing industry of Siberia.

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

During the expedition on the ship "Zhannetta" (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 New Siberian Islands to Spitsbergen. Analysis of data from eleven depth measurements made during this drift showed that the depth of A. b. in this area it ranges from 3400 to 4000 m. This was the first time it was established that at least part of A. b. occupies a deep-sea depression.

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 “isanomalous overheating” of the atmosphere due to the heat of the ocean, the influence of which on atmospheric processes and climatic conditions appear all the way to Lake Baikal. The Arctic Ocean, especially its Arctic basin, plays the role of one of the planetary “sinks” of heat in both the atmosphere and the ocean.

2. EAST SIBERIAN SEA

The East Siberian Sea is located between the New Siberian Islands and the island. 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 the island. Kotelny with the edge of the mainland shallows (79° N, 139° E) to the northern tip of this island (Cape Anisiy), then along the eastern shores of the New Siberian Islands to Cape Svyatoy Nos (Dmitry Laptev Strait). The northern border runs along the edge of the continental shelf from the point with coordinates 79° N. latitude, 139° east. to a point with coordinates 76° N. la., 180° east. d., and the eastern border - from the point with these coordinates along the meridian 180° to the island. Wrangel, then along its northwestern shore 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, its average depth is 54 m, its greatest depth is 915 m, i.e. this sea lies entirely on the continental shallows.

2.1. Shores.

Suspended sediment carried by rivers causes changes in depths in coastal areas and the formation of bars at river mouths. The Indigirka River carries out 16.7 million tons of suspended sediment 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 of river waters on adjacent coastal areas, intense thermal abrasion of the estuary areas of the coast occurs. According to available data, the rate of abrasion ranges from 1-5 to 10-15 m/year.

Where the coast is composed of bedrock (the region of Cape Baranov and Cape Shelagsky, the western coast of Wrangel Island, 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 shore of the Longa Strait.

2.2. Bottom structure.

The underwater relief of the shelf that forms the bed of the sea is, in general terms, a plain, very slightly inclined from southwest to northeast. The seabed has no noticeable depressions or hills. The predominant depths are up to 20-25 m. 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 seabed 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 alluvium from the ancient river systems of the paleo-Indigirka and paleo-Kolyma, traces of which can still be discerned on the seabed. Most of the archipelagos and individual islands found in the shelf area are composed of rocks of this basement (Bear, Rautan, Shalaurov Islands, part of Ayon Island, etc.). In the area 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, covered and bordered by Mesozoic rocks, in places folded.

Bottom sediments of the shelf consist mainly of sandy silt containing crushed boulders and pebbles; some of them are fragments of rocks from the island. Wrangel or other islands brought by ice.

2.3. Characteristic climate.

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

In winter, the main influence on the sea is exerted by the spur of the Siberian High, which extends to the coast, and the crest of the polar anticyclone is weakly expressed. In this regard, southwestern and southern 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 disrupted by cyclonic incursions. Atlantic cyclones in the west of the sea cause increased wind and some warming, and 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. On mountainous areas of the coast, the passage of Pacific cyclones is associated with the formation of a local wind - a foehn. It usually reaches storm force, causing a slight increase in temperature and a decrease in air humidity.

In summer, the pressure over the mainland of Asia is reduced, and over the sea it is increased, so winds from the northern directions predominate. 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. The wind often blows at a speed of 10-15 m/s. The increase in wind here is due to hair dryers. The southeastern part of the sea is much calmer. Steady northern and northeastern winds cause low air temperatures. The average July temperature is 0-1°C in the north of the sea and 2-3°C in coastal areas. In the summer, the weather over the East Siberian Sea is mostly cloudy with light drizzling rain, and sometimes there is sleet.

In autumn there is almost no return of heat, 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 outlying areas of the sea, and calm in the central part are 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 flowing into east direction from the Kolyma region. It is this warm current that clears the Long Strait of ice. At a distance 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 remains 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 an area of high pressure develops near the pole, the anticyclonic (clockwise) circulation of water intensifies, which forces the ice to drift in a northwesterly direction. The average daily speed of ice drift 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, on the contrary, favors the influx 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 flow, 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 flow is 132 km 3 . The second largest river flow. Indigirka brings 59 km 3 of water. The total continental flow into the East Siberian Sea is about 250 km 3 /year, which is only 10% of the total river flow into all Arctic seas. All river water flows into the southern part of the sea, and approximately 90% of the flow occurs, as in other Arctic seas, in the summer months.

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

Constant currents on the surface of the East Siberian Sea form a weakly expressed cyclonic circulation. Along the continental coast there is a steady transport of water from west to east. At Cape Billinga, part of the water is directed to the north and northwest and is carried to the northern outskirts of the sea, where it is included in the flows going to the west. Under different weather conditions, the movement of water also changes. Part of the water from the East Siberian Sea is carried through the Long Strait into the Chukchi Sea. Constant currents are often disturbed by wind currents, which are often stronger than constant ones. The influence of tidal currents is 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 extends from the north-northwest to the east-southeast from the New Siberian Islands to the island. Wrangel.

The annual variation of the level is characterized by its highest position in June - July, when there is an abundant influx of river water. A reduction in continental runoff in August leads to a drop in level by 50-70 cm. As a result of the predominance of surge winds in the fall, in October, the level rises.

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

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

Significant waves develop in ice-free areas of the sea. It is strongest during stormy northwestern and southeastern winds, which have the greatest acceleration over the surface of clear water. 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 retreats to the north. The western part of the sea is rougher than the eastern. Its central areas are relatively calm.

Water temperature on the surface in all seasons it generally decreases from south to north. In winter it is close to the freezing point and near river mouths 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 ice conditions. The water temperature in bays and bays reaches 7-8°, in open, ice-free areas 2-3°, and at the ice edge it is close to 0°.

The change in water temperature with depth in winter and spring is little noticeable. Only near the mouths of large rivers does it drop to -0.5° in subglacial horizons and to -1.5° at the bottom. In summer, in the free spaces of the Otold, 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, the surface temperature is observed in a layer of 3-5 m, from where it drops sharply to horizons of 5-7 m and then gradually decreases towards the bottom. In zones of influence of coastal runoff, a uniform temperature covers a layer of up to 7-10 m; between horizons of 10-20 m it sharply, and then gradually decreases to the bottom. The shallow, weakly warmed 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 equal 4 -5°/00 near the mouths of Kolyma and Indigirka, reaches values of 24-26°/00 near the Bear Islands, increases to 28-30°/00 in the central regions of the sea and rises to 31-32°/00 on its northern outskirts. In summer, as a result of the influx of river water and melting ice, surface salinity values decrease 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 the melting ice.

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

Autumn-winter convection in the East Siberian Sea at depths of 40-50 m, which occupy more than 70% of its total area, penetrates to the bottom. By the end of the cold season, winter vertical circulation extends to horizons of 70-80 m, where it is limited by the greater 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 transport of ice from the Arctic basin to the sea predominates, in contrast to other Arctic seas, where outflow ice drift prevails. A characteristic feature of the ice of the East Siberian Sea is the significant development of fast ice in winter. Moreover, 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 connects with the fast ice of the Laptev Sea. In the central regions its width is 250-300 km and 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 to the southeast, approaching the coast of the mainland at Cape Shelagsky. By the end of winter, the thickness of the fast ice reaches 2 m. From west to east, the thickness of the fast ice decreases. Behind the fast ice there is drifting 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 winds from the south in winter often carry drifting ice away from the northern edge of the fast ice. As a result, significant expanses of clean water and young ice appear, forming the Novosibirsk stationary french polynyas in the west and Zavrangelevskaya in the east.

At the beginning of summer, after the opening 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 island. Wrangel - New Siberian Islands. In the western part of the sea, on the site of extensive fast ice, the Novosibirsk ice massif is formed. It consists mainly of first-year ice and usually collapses by the end of summer. The overwhelming majority of the space in the east of the sea is occupied by a spur of the Aion oceanic ice massif, which largely forms heavy multi-year ice. Its southern periphery is almost adjacent to the coast of the mainland throughout the year, determining the ice situation in the sea.

2.6. Biology.

The flora and fauna of the East Siberian Sea is qualitatively poor compared to neighboring seas, mainly due to harsh ice conditions. However, in the areas of river mouths, in addition to omul, whitefish and grayling, there are large schools of white fish (Coregonidae). Other species of fish were also found there, which include polar smelt, navaga, polar cod, polar flounder and salmonids: 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 21st century. – M.: Nauka, 1991. – 128 p.

2. Sukhovey F.S. Seas of the world's oceans. – L.: Gidrometeoizdat, 1986. – 288 p.

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

4. Zalogin B. S., Kosarev A. N. Seas. – M.: Mysl, 1999. – 400 p.

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

General climatic description of the region

The East Siberian Sea is a marginal sea of the Arctic Ocean, located between the New Siberian Islands and Wrangel Island. The name was assigned at the suggestion of Yu.M. Shokalsky by the Russians geographical society, approved by a resolution of the Central Executive Committee of the USSR on June 27, 1935. The eastern border of the sea passes through Wrangel Island and Long Strait. In the north from the northernmost point of Wrangel to Henrietta, Zhannetta Island and further to the northern point of Kotelny Island. The southern border runs along the coast of the mainland from Cape Svyatoy Nos in the west to Cape Yakan in the east. The sea is connected through straits to the Chukchi Sea and the Laptev Sea. It is connected to the Laptev Sea through the Sannikov, Eterikan and Dmitry Laptev straits. It is connected to the Chukchi Sea through the Long Strait. The area of the sea is about 940 thousand sq. km. This sea is completely located on the shelf, as a result of which its bottom is a plain, gradually descending to the north. The depth is small and averages about 55 m. The shores are indented by bays (Kolyma Bay, Omulyakhskaya and Chaunskaya Bay). West Coast The mainland is flat, the eastern part is mountainous with cliffs. A few islands form groups: the New Siberian Islands, the Bear Islands, and the Shalaurov Islands. Some islands are being destroyed because they are made entirely of sand and ice. Rivers flowing into the sea: Indigirka, Lapcha, Khroma, Kolyma, Alazeya, etc.

Climate of the East Siberian Sea

The climate is arctic, influenced by the air masses of two oceans: the Pacific and the Atlantic. In winter, southwestern and southern winds blow, carrying cold air from Siberia, so the average temperature in winter is -30 degrees Celsius. In summer, northerly winds blow, and the air temperature is 0-1 degrees Celsius in the open sea and 2-3 degrees Celsius on the coast. The sky is cloudy with frequent rain and sleet. The shores are covered in fog; it can last up to 70 days. The annual precipitation is 200 mm.

Wind mode

IN winter time The Siberian maximum determines 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. The winds bring storms with waves 3-5 meters high in the western part of the sea region, while in the east it is relatively calm. Storms usually last 1-2 days in summer and 3-5 days in winter.

Atlantic cyclones, which prevail in the western part of the sea, contribute to stronger winds and higher temperatures. Pacific cyclones, which prevail in the southeastern part of the sea, bring strong winds, snowstorms and cloudy weather. On coasts with mountainous terrain, the Pacific cyclone contributes to the formation of a strong wind - a foehn. As a result of this storm wind, the temperature rises, while the air humidity becomes less. In summer, zones of high pressure form over the sea, and zones of low pressure form over land. In this regard, winds blow predominantly from the north. At the beginning of the warm season, the winds do not yet gain sufficient strength, but by mid-summer their speed averages 6 - 7 m/s. By the end of summer, the western part of the sea turns into areas of strong storms. At this time, this section becomes the most dangerous along the entire Northern Sea Route. Very often the wind speed reaches 10 - 15 m/s. In the southeastern part of the sea such strong winds are not observed. The wind speed here can only increase due to hair dryers.

Air temperature

The average temperature in January is approximately - 28 - 30°C. In winter, the weather is mostly clear. Constant winds from the northern and northeastern directions contribute to the preservation low temperatures air.

In summer in the northern part of the sea the average July temperature is about 0 - +1°C, in coastal areas the temperature is slightly higher than +2 - 3°C. 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 the warm continent contributes to an increase in temperature. In autumn the influence of the Pacific and Atlantic Oceans weakens, which affects the decrease in air temperature. Thus, the East Siberian Sea is characterized by cold summers; unstable windy weather in the western and eastern regions of the sea in the summer-autumn period.

Water temperature

Sea water temperatures are low; in the north they are close to -1.8°C in both winter and summer. To the south, in summer the temperature rises in the upper layers to 5 C. At the edge of the ice fields, the temperature is 1-2 C. The maximum water temperature reaches the end of summer at the mouths of rivers. In general, water surface temperatures decrease from south to north. In winter in river deltas it is -0.2 and -0.6 degrees Celsius. And in the northern part of the sea it drops to -1.8 degrees Celsius. In summer, the water in the bays warms up to 7-8 degrees Celsius, and in ice-free sea areas it is 2-3 degrees Celsius.

The change in water temperature with depth in winter and spring is little noticeable. Only near the mouths of large rivers does it drop to -0.5° in subglacial horizons and to -1.5° at the bottom. In summer, in ice-free areas, the water temperature decreases slightly from the surface to the bottom in the coastal zone in the west of the sea. In its eastern part, the surface temperature is observed in a layer of 3-5 m, from where it sharply drops to horizons of 5-7 m and then gradually decreases towards the bottom. In zones of influence of coastal runoff, a uniform temperature covers a layer of up to 7-10 m, between horizons of 10-20 m it sharply, and then gradually decreases to the bottom.

In general, the shallow, weakly warmed East Siberian Sea is one of the coldest Arctic seas.

Salinity of water

The salinity of water is different in the western and eastern parts of the sea. In the eastern part of the sea at the surface it is usually about 30 ppm. River flow in the eastern part of the sea leads to a decrease in salinity to 10-15 ppm, and at the mouths of large rivers to almost zero. Near ice fields, salinity increases to 30 ppm. With depth, salinity increases to 32 ppm.

IN surface waters salinity increases from southwest to northeast. In the area of river deltas in winter and spring it is 4-5 ppm. In open waters it reaches 28-30 ppm, and in the north up to 31-32 ppm. In summer, salinity decreases by 5% due to snow melting.

Ice regime

The sea is covered with ice almost all year round. The ice thickness reaches 2 meters by the end of winter and decreases from west to east.

In the eastern part of the sea, even in summer, floating perennial ice (up to 2-3 meters thick) remains. From the coast they can be driven north by winds from the mainland.

The ice drifts in a northwesterly direction as a result of water circulation under the influence of anticyclones at the pole. After the anticyclone weakens, the area of the cyclonic gyre increases and multi-year ice enters the sea.

Ice melting begins in May from the Kolyma River delta. In summer, the coastal part in the west is free of ice; in the east there are floating ice floes.

The sea freezes completely in October-November.

Hydrochemical conditions

The characteristic features of the hydrochemical conditions of the East Siberian Sea illustrate the content and distribution of oxygen and phosphates in it. In autumn and winter, the waters of the East Siberian Sea are well aerated. Relative oxygen content over time