The Sea of ​​Japan is freezing. Japanese Sea

It is located between the Asian mainland, the Japanese archipelago and Sakhalin Island. Its shores belong to countries such as Japan, South Korea, North Korea and Russia.

The reservoir is significantly isolated from Pacific waters. This isolation affects both the fauna and the salinity of the water. The latter is below the oceanic one. The water balance is regulated by inflows and outflows through the straits connecting the sea with neighboring seas and the ocean. Reset fresh water makes an insignificant contribution to water exchange and amounts to no more than 1%.

Geography

The area of ​​the reservoir is 979 thousand square meters. km. The maximum depth is 3742 meters. Average depth corresponds to 1752 meters. The volume of water is 1630 thousand cubic meters. km. The length of the coastline is 7600 km. Of these, 3240 km belong to Russia. From north to south, the length of the sea is 2255 km. The maximum width corresponds to 1070 km.

Islands

There are no large islands. Most of small islands located off the east coast. The most significant islands include: Moneron (area 30 sq. km), Okushiri (142 sq. km), Oshima (9.73 sq. km), Sado (855 sq. km), Ulleungdo (73.15 sq. km) , Russian (97.6 sq. km).

Bays

Coastline relatively straight. One of the largest is Peter the Great Bay with a total area of ​​about 9 thousand square meters. km. The length from north to south is 80 km, from west to east it is 200 km. The length of the coastline is 1230 km. The cities of Vladivostok and Nakhodka are located in the bay. In North Korea there is East Korea Bay, and on the island of Hokkaido there is Ishikari Bay. In addition, there are many small bays.

Straits

The Sea of ​​Japan is connected to the East China Sea, the Sea of ​​Okhotsk and the Pacific Ocean by straits. This is the Strait of Tartary between Asia and Sakhalin Island with a length of 900 km. The La Perouse Strait between Sakhalin Island and Hokkaido Island with a length of 40 km. Sangar Strait between the islands of Honshu and Hokkaido. Its length is 96 km.

The Shimonoseki Strait separates the islands of Honshu and Kyushu. There are railway, road and pedestrian tunnels underneath it. The Korea Strait, with a length of 324 km, connects the body of water we are considering with the East China Sea. It divides the Tsushima Islands into 2 parts: the Western Passage and the Eastern Passage (Tsushima Strait). Through this strait, the warm Pacific Kuroshio Current enters the reservoir.

Sea of ​​Japan on the map

Climate

The maritime climate is characterized by warm water and monsoons. The northern and western regions are colder than the southern and eastern regions. During the winter months average temperature air in the north is minus 20 degrees Celsius, and in the south it is plus 5 degrees Celsius. In summer, humid and warm air blows from the northern regions Pacific Ocean. August is considered the warmest month. At this time, the average temperature in the north is 15 degrees Celsius, and in the south it is 25 degrees Celsius.

Annual precipitation is minimal in the northwest and maximum in the southeast. Typhoons are typical for autumn. The wave height during this period reaches 8-12 meters. In winter, the Tatar Strait (90% of all ice) and Peter the Great Bay are covered with ice. The ice crust stays on the water for about 4 months.

Ebbs and flows

The reservoir is characterized by complex tides. They have a semi-diurnal cycle in the Korea Strait and in the north of the Tartary Strait. On east coast Korea, the Far Eastern coast of Russia, and on the coast of the Japanese islands of Hokkaido and Honshu they are daytime. Mixed tides are typical for Peter the Great Bay.

The amplitude of the tides is relatively low. It varies from 0.5 to 3 meters. In the Tatar Strait, the amplitude ranges from 2.3 to 2.8 meters due to its funnel-shaped shape. The water level also experiences seasonal fluctuations. The highest is observed in summer, and the lowest in winter. The level is also affected by wind. He is able to change it by 20-25 cm in relation to the Korean coast to the Japanese coast.

Water clarity

Sea water has a color from blue to green-blue. Transparency is about 10 meters. Water Sea of ​​Japan rich in dissolved oxygen. This is especially true for the western and northern regions. They are colder and contain more phytoplankton compared to the eastern and southern regions. The oxygen concentration is 95% near the surface and decreases to 70% at a depth of 3 thousand meters.

Fishing on the Sea of ​​Japan

Fishing

Fishing is considered the main economic activity. It is carried out near the continental shelf, and priority is given to fish such as herring, tuna, and sardines. Squid are caught mainly in the central sea areas, and salmon off the southwestern and northern coasts. Along with fishing, algae production is well developed. The Russian whaling fleet is based in Vladivostok, although it fishes in the northern seas.

Separates from him Japanese islands and the island of Sakhalin. It washes the shores of Russia, Korea, Japan, and the DPRK. In the south, a branch of the warm Kuroshio Current enters.

Area - 1.062 million sq. km.

The greatest depth is 3742 m.
The northern part of the sea freezes in winter.

Fishing; production of crabs, sea cucumbers, algae.

map of the sea of ​​japan
map of the sea of ​​japan
Main ports: Vladivostok, Nakhodka, Vostochny, Sovetskaya Gavan, Vanino, Aleksandrovsk-Sakhalinsky, Kholmsk, Niigata, Tsuruga, Maizuru, Wonsan, Hungnam, Chongjin, Busan.

Climate of the Sea of ​​Japan

moderate, monsoon. The northern and western parts of the sea are much colder than the southern and eastern. In the coldest months (January-February), the average air temperature in the northern part of the sea is about?20°C, and in the south about +5°C. The summer monsoon brings warm and humid air.
The average air temperature of the warmest month (August) in the northern part is approximately +15°C, in the southern regions about +25°C. In autumn, the number of typhoons caused by hurricane winds increases. The largest waves have a height of 8-10 m, and during typhoons, the maximum waves reach a height of 12 m.

In summer, the surface water temperature rises from 18-20°C in the north to 25-27°C in the south of the sea.
Salinity of water Sea of ​​Japan 33.7-34.3%, which is slightly lower than the salinity of the waters of the World Ocean.

Tides in Sea of ​​Japan clearly expressed, to a greater or lesser extent in different areas. The greatest level fluctuations are observed in the extreme northern and extreme southern regions. Seasonal fluctuations in sea level occur simultaneously over the entire surface of the sea; the maximum rise in level is observed in summer.

Flora and fauna

The underwater world of the northern and southern regions Sea of ​​Japan very different. In the cold northern and northwestern regions, the flora and fauna of temperate latitudes has formed, and in the southern part of the sea, south of Vladivostok, a warm-water faunal complex predominates. Off the coast Far East There is a mixture of warm-water and temperate fauna. Here you can find octopuses and squids - typical representatives warm seas. At the same time, vertical walls overgrown with sea anemones, gardens of brown algae - kelp - all this is reminiscent of the landscapes of the White and Barents Seas.
IN Sea of ​​Japan a huge abundance of starfish and sea ​​urchins, of various colors and sizes, brittle stars, shrimps, and small crabs are found (Kamchatka crabs are found here only in May, and then they move further into the sea). Bright red ascidians live on rocks and stones. The most common shellfish is scallops. Of fish are often found blennies, sea ruffes.

In the Sea of ​​Japan, the ice cover reaches its maximum development in mid-February. On average, ice covers 52% of the area of ​​the Tatar Strait and 56% of the Peter the Great Bay.

Ice melting begins in the first half of March. In mid-March, the open waters of Peter the Great Bay are cleared of ice and all seaside coast to Cape Zolotoy. The ice boundary in the Tatar Strait retreats to the northwest, and in the eastern part of the strait clearing of ice occurs at this time. Early clearing of the sea from ice occurs in the second ten days of April, later - at the end of May - beginning of June.

The Sea of ​​Japan belongs to the Pacific Ocean basin. This body of water is separated from the ocean by the Japanese Islands and Sakhalin Island. Its waters wash the shores of Japan, Korea, Russia and the DPRK. The vast warm Kuroshio Current runs through the southern part of the sea.

Geographical features

A map of the Sea of ​​Japan shows that it has natural boundaries. But in some places it is limited conditionally. Its border with the Sea of ​​Okhotsk runs along the line Cape Sushchev - Cape Tyk. The Sea of ​​Japan has an area of ​​over 1 million square meters. km. Its maximum depth was recorded at a point equal to 3742 m.
The sea stretches along the meridian and narrows to the north. It is smaller in size than Okhotsk and Bering Sea. However, the Sea of ​​Japan is one of the deepest and largest Russian seas. In this sea there are no large islands. But the small islands include Moneron, Rishiri, Rebun, Oshima, Putyatin, Askold, Ullyndo, Russky, etc. The coast of the Sea of ​​Japan is slightly indented. There are no bays and bays that protrude deep into the mainland. In terms of outline, the coast of Sakhalin Island is the simplest.

Climatic conditions

The Sea of ​​Japan is an area dominated by a monsoon temperate climate. The northern sea is covered with ice in winter. It is much warmer in the south and east. In the northern region of the ocean, the air cools down to -20 degrees in winter. In summer, the monsoons bring humid and warm air. In the southern part of the ocean the air temperature is +25 degrees. Typhoons are common in the autumn months. Waves during a typhoon can reach 12 m in height. Currents in the sea form gyres. Animal and vegetable world varies depending on the area of ​​the sea. In the cool northern regions, temperate latitude nature predominates. The southern part of the Sea of ​​Japan is home to animals that need warm water. The sea is rich in shrimp, crabs, ruffes, scallops and other inhabitants.
Primorye is characterized by abundant algae and grasses. There are over 200 species of algae in Peter the Great Bay. Of them great importance for humans, seaweed has. In the waters of the bays there are giant oysters that live at a depth of no more than 7 m. In the Sea of ​​Japan, sea scallops and Kamchatka crabs are bred. Squid and octopus are harvested there. This sea is home to different species of sharks. The most common is the Katran shark, which is not dangerous to people. There are seals, whales and dolphins in the Sea of ​​Japan.

The Sea of ​​Japan lies between the continent of Asia, the Korean Peninsula, and Sakhalin and the Japanese islands, separating it from the ocean and two neighboring seas. In the north, the border between the Sea of ​​Japan and the Sea of ​​Okhotsk runs along the line between Cape Sushchev and Cape Tyk on Sakhalin. In the La Perouse Strait, the border is the line between Cape Soya and Cape Crillon. In the Sangar Strait, the border runs along the line of Cape Syria - Cape Estan, and in the Korea Strait - along the line of Cape Nomo (Kyushu Island) - Cape Fukae (Goto Island) - Island. Jeju - Korean Peninsula.

The Sea of ​​Japan is one of the largest and deepest seas in the world. Its area is 1062 km 2, volume - 1631 thousand km 3, average depth - 1536 m, greatest depth - 3699 m. This is a marginal oceanic sea.

There are no large islands in the Sea of ​​Japan. Of the small ones, the most significant are the islands of Moneron, Rishiri, Okushiri, Ojima, Sado, Okinoshima, Ullyndo, Askold, Russky, and Putyatina. Tsushima Island is located in the Korea Strait. All islands (except Ulleungdo) are located near the coast. Most of them are located in the eastern part of the sea.

The coastline of the Sea of ​​Japan is relatively slightly indented. The simplest in outline is the coast of Sakhalin; the coasts of Primorye and the Japanese Islands are more winding. The large bays of the mainland coast include De-Kastri, Sovetskaya Gavan, Vladimir, Olga, Peter the Great, Posyet, Koreysky, on the island. Hokkaido - Ishikari, on the island. Honshu - Toyama and Wakasa.

Landscapes of the Sea of ​​Japan

The coastal boundaries are cut through by straits that connect the Sea of ​​Japan with the Pacific Ocean, the Sea of ​​Okhotsk and the East China Sea. The straits vary in length, width and, most importantly, depth, which determines the nature of water exchange in the Sea of ​​Japan. Through the Sangar Strait, the Sea of ​​Japan communicates directly with the Pacific Ocean. The depth of the strait in the western part is about 130 m, in the eastern part, where it is located maximum depths, about 400 m. The Nevelskoy and La Perouse straits connect the Japanese and Sea of ​​Okhotsk. The Korea Strait, divided by the islands of Jeju, Tsushima and Ikizuki into the western (Broughton passage with the greatest depth of about 12.5 m) and eastern (Kruzenshtern passage with the greatest depth of about 110 m) parts, connects the Sea of ​​Japan and the East China Sea. The Shimonoseki Strait, with depths of 2-3 m, connects the Sea of ​​Japan with the Inland Sea of ​​Japan. Due to the shallow depths of the straits and the great depths of the sea itself, conditions are created for isolating its deep waters from the Pacific Ocean and adjacent seas, which is the most important natural feature Sea of ​​Japan.

The coast of the Sea of ​​Japan, varied in structure and external forms in different areas, belongs to different morphometric types of coasts. These are predominantly abrasive, mostly unaltered, shores. To a lesser extent, the Sea of ​​Japan is characterized by accumulative shores. This sea is surrounded by predominantly mountainous shores. In some places, single rocks - kekurs - characteristic formations of the Sea of ​​Japan coast rise from the water. Low-lying shores are found only on certain sections of the coast.

Bottom relief

Bottom topography and currents of the Sea of ​​Japan

According to the nature of the bottom topography, the Sea of ​​Japan is divided into three parts: northern - north of 44° N, central - between 40 and 44° N. and southern - south of 40° N.

The northern part of the sea is like a wide trench, gradually rising and narrowing towards the north. Its bottom in the direction from north to south forms three steps, which are separated from one another by clearly defined ledges. The northern step is located at a depth of 900-1400 m, the middle one is at a depth of 1700-2000 m, and the southern step is at a depth of 2300-2600 m. The surfaces of the steps are slightly inclined to the south.

The coastal sandbank of Primorye in the northern part of the sea is approximately 20 to 50 km long, the edge of the sandbank is located at a depth of about 200 m.

The surfaces of the northern and middle steps of the central trench are more or less level. The relief of the southern step is significantly complicated by numerous individual uplifts up to 500 m high. Here, on the edge of the southern step, at a latitude of 44°, there is a vast hill called “Vityaz” with a minimum depth above it of 1086 m.

The southern step of the northern part of the Sea of ​​Japan breaks off with a steep ledge to the bottom of the central basin. The steepness of the ledge is on average 10-12°, in some places 25-30°, and the height is approximately 800-900 m.

The central part of the sea is a deep closed basin, slightly elongated in the east-northeast direction. From the west, north and east it is limited by the steep slopes of mountain structures sloping into the sea in Primorye, the Korean Peninsula, the islands of Hokkaido and Honshu, and from the south by the slopes of the Yamato underwater hill.

In the central part of the sea, coastal shallows are very poorly developed. A relatively wide sandbank is found only in the area of ​​southern Primorye. The edge of the shallows in the central part of the sea is very clearly expressed throughout its entire length. The bottom of the basin, located at a depth of about 3500 m, in contrast to the complexly dissected surrounding slopes, is leveled. On the surface of this plain there are isolated hills. Approximately in the center of the basin there is an underwater ridge stretching from north to south with a height of up to 2300 m. The southern part of the sea has a very complex topography, since in this area there are the marginal parts of large mountain systems- Kuril-Kamchatka, Japanese and Ryu-Kyu. Here is the vast underwater Yamato Rise, which consists of two ridges elongated in the east-northeast direction with a closed basin located between them. From the south, a wide underwater ridge of approximately meridional strike adjoins the Yamato Rise.

In many areas of the southern part of the sea, the structure of the underwater slope is complicated by the presence of underwater ridges. On the underwater slope of the Korean Peninsula, wide underwater valleys can be traced between the ridges. The continental shelf is no more than 40 km wide throughout almost its entire length. In the area of ​​the Korea Strait, the shallows of the Korean Peninsula and about. The Honshu close together and form shallow waters with depths of no more than 150 m.

Climate

The Sea of ​​Japan lies entirely in the monsoon climate zone of temperate latitudes. In the cold season (from October to March) it is influenced by the Siberian anticyclone and the Aleutian low, which is associated with significant horizontal gradients of atmospheric pressure. In this regard, strong northwest winds with speeds of 12-15 m/s and more dominate over the sea. Local conditions change wind conditions. In some areas, under the influence of coastal topography, there is a high frequency of northern winds, in others, calms are often observed. On the southeast coast, the regularity of the monsoon is disrupted; western and northwestern winds predominate here.

During the cold season, continental cyclones enter the Sea of ​​Japan. They cause strong storms, and sometimes severe hurricanes, which last for 2-3 days. At the beginning of autumn (September), tropical cyclones-typhoons sweep over the sea, accompanied by hurricane winds.

The winter monsoon brings dry and cold air to the Sea of ​​Japan, the temperature of which increases from south to north and from west to east. In the coldest months - January and February - the average monthly air temperature in the north is about -20°, and in the south about 5°, although significant deviations from these values ​​are often observed. During the cold seasons, the weather is dry and clear in the northwestern part of the sea, wet and cloudy in the southeast.

In warm seasons, the Sea of ​​Japan is affected by the Hawaiian High and, to a lesser extent, by the depression that forms in the summer over Eastern Siberia. In this regard, southern and southwestern winds prevail over the sea. However, pressure gradients between areas of high and low pressure are relatively small, so wind speeds average 2-7 m/s. A significant increase in wind is associated with the entry of oceanic, and less often continental, cyclones into the sea. In summer and early autumn (July-October), the number of typhoons over the sea increases (with a maximum in September), causing hurricane-force winds. In addition to the summer monsoon, strong and hurricane winds associated with the passage of cyclones and typhoons, local winds are observed in different areas of the sea. They are mainly caused by the peculiarities of coastal orography and are most noticeable in the coastal zone.

In the Far Eastern seas

The summer monsoon brings warm and humid air. Average monthly temperature the warmest month - August - in the northern part of the sea is approximately 15°, and in the southern regions about 25°. In the northwestern part of the sea, significant cooling is observed due to the influx of cold air brought by continental cyclones. In spring summer time Cloudy weather with frequent fog prevails.

A distinctive feature of the Sea of ​​Japan is the relatively small number of rivers flowing into it. The largest of them is Suchan. Almost all rivers are mountainous. Continental flow into the Sea of ​​Japan is approximately 210 km 3 /year and is fairly evenly distributed throughout the year. Only in July does the river flow increase slightly.

The geographical location, the outlines of the sea basin, separated from the Pacific Ocean and adjacent seas by high thresholds in the straits, pronounced monsoons, water exchange through the straits only in the upper layers are the main factors in the formation of the hydrological conditions of the Sea of ​​Japan.

The Sea of ​​Japan receives a large amount of heat from the sun. However, the total heat consumption for effective radiation and evaporation exceeds the supply of solar heat, therefore, as a result of processes occurring at the water-air interface, the sea loses heat annually. It is replenished by the heat brought by Pacific waters entering the sea through the straits, therefore, on the average long-term value, the sea is in a state of thermal equilibrium. This indicates the important role of water heat exchange, mainly heat influx from outside.

Hydrology

Significant natural factors are the exchange of water through the straits, the flow of precipitation onto the sea surface and evaporation. The main influx of water into the Sea of ​​Japan occurs through the Korea Strait - about 97% of the total annual amount of incoming water. The largest flow of water goes through the Sangar Strait - 64% of the total flow; 34% flows through the La Perouse and Korean straits. The share of fresh components of the water balance (continental runoff, precipitation) remains only about 1%. Thus, main role Water exchange through the straits plays a role in the water balance of the sea.

Scheme of water exchange through straits in the Sea of ​​Japan

Features of the bottom topography, water exchange through the straits, and climatic conditions form the main features of the hydrological structure of the Sea of ​​Japan. It is similar to the subarctic type of structure of the adjacent areas of the Pacific Ocean, but has its own characteristics that have developed under the influence of local conditions.

The entire thickness of its waters is divided into two zones: surface - to a depth of an average of 200 m and deep - from 200 m to the bottom. The waters of the deep zone are relatively uniform in physical properties throughout the year. The characteristics of surface water under the influence of climatic and hydrological factors change in time and space much more intensely.

In the Sea of ​​Japan, three water masses are distinguished: two in the surface zone: the surface Pacific, characteristic of the southeastern part of the sea, and the surface Sea of ​​Japan - for the northwestern part of the sea, and one in the deep part - the deep Sea of ​​Japan water mass.

The surface Pacific water mass is formed by the water of the Tsushima Current; it has the largest volume in the south and southeast of the sea. As you move north, its thickness and area of ​​distribution gradually decrease, and at approximately 48° N latitude. due to a sharp decrease in depth, it wedges out into shallow water. In winter, when the Tsushima Current weakens, the northern boundary of the Pacific waters is located at approximately 46-47° N latitude.

Water temperature and salinity

Surface Pacific water is characterized by high temperatures (about 15-20°) and salinity (34-34.5‰). This water mass contains several layers, the hydrological characteristics of which and their thickness vary throughout the year:

the surface layer, where the temperature throughout the year varies from 10 to 25°, and salinity - from 33.5 to 34.5‰. The thickness of the surface layer varies from 10 to 100 m;

the upper intermediate layer has a thickness varying from 50 to 150 m. It exhibits significant gradients in temperature, salinity and density;

the lower layer has a thickness of 100 to 150 m. The depth of its occurrence and the boundaries of its distribution change throughout the year; temperature varies from 4 to 12°, salinity - from 34 to 34.2‰. The lower intermediate layer has very slight vertical gradients in temperature, salinity and density. It separates the surface Pacific water mass from the deep Sea of ​​Japan.

As you move north, the characteristics of Pacific water gradually change under the influence of climatic factors as a result of its mixing with the underlying deep Sea of ​​Japan water. With the cooling and desalination of Pacific water at latitudes 46-48° N. The surface water mass of the Sea of ​​Japan is formed. It is characterized by relatively low temperature (on average about 5-8°) and salinity (32.5-33.5‰). The entire thickness of this water mass is divided into three layers: surface, intermediate and deep. As in the Pacific Ocean, in the surface water of the Japanese Sea, the greatest changes in hydrological characteristics occur in the surface layer with a thickness of 10 to 150 m or more. The temperature here varies throughout the year from 0 to 21°, salinity - from 32 to 34‰. In the intermediate and deep layers, seasonal changes in hydrological characteristics are insignificant.

Deep Sea of ​​Japan water is formed as a result of the transformation of surface waters that descend to depths due to the process of winter convection. The vertical changes in the characteristics of the deep Sea of ​​Japan water are extremely small. The bulk of these waters have a temperature of 0.1-0.2° in winter, 0.3-0.5° in summer, and a salinity throughout the year of 34.1-34.15‰.

Water temperature on the surface of the seas of Japan, Yellow, East China, South China, Philippines, Sulu, Sulawesi in summer

The structural features of the waters of the Sea of ​​Japan are well illustrated by the distribution of oceanological characteristics in it. Surface water temperatures generally increase from northwest to southeast.

In winter, the water temperature on the surface rises from negative values ​​close to 0° in the north and northwest to 10-14° in the south and southeast. This season is characterized by a well-defined contrast in water temperature between western and eastern parts sea, and in the south it is less pronounced than in the north and central part of the sea. Thus, at the latitude of Peter the Great Bay, the water temperature in the west is close to 0°, and in the east it reaches 5-6°. This is explained, in particular, by the influence of warm waters moving from south to north in the eastern part of the sea.

As a result of spring warming, the surface water temperature throughout the sea rises quite quickly. At this time, temperature differences between the western and eastern parts of the sea begin to smooth out.

In summer, the surface water temperature rises from 18-20° in the north to 25-27° in the south of the sea. Temperature differences across latitude are relatively small.

U western shores the water temperature on the surface is 1-2° lower than in the east, where warm waters spread from south to north.

In winter, in the northern and northwestern regions of the sea, the vertical water temperature changes slightly, and its values ​​are close to 0.2-0.4°. In the central, southern and southeastern parts of the sea, the change in water temperature with depth is more pronounced. In general, the surface temperature, equal to 8-10°, remains up to horizons of 100-150 m, from which it gradually decreases with depth to approximately 2-4° at horizons of 200-250 m, then it decreases very slowly - to 1-1. 5° at horizons of 400-500 m, deeper the temperature drops slightly (to values ​​less than 1°) and remains approximately the same to the bottom.

In summer, in the north and northwest of the sea, high surface temperature (18-20°) is observed in the 0-15 m layer, from here it drops sharply with a depth of up to 4° at a horizon of 50 m, then its decrease occurs very slowly to a horizon of 250 m, where it is approximately 1°, deeper and to the bottom the temperature does not exceed 1°.

In the central and southern parts of the sea, the temperature decreases quite smoothly with depth and at a horizon of 200 m is approximately 6°, from here it decreases somewhat faster and at horizons of 250-260 m it is equal to 1.5-2°, then it decreases very slowly at horizons 750-1500 m (in some areas at horizons of 1000-1500 m) reaches a minimum of 0.04-0.14°, from here the temperature rises towards the bottom to 0.3°. The formation of an intermediate layer of minimum temperature values ​​is presumably associated with the immersion of the waters of the northern part of the sea, cooled during severe winters. This layer is quite stable and is observed all year round.

Salinity on the surface of the seas of Japan, Yellow, East China, South China, Philippines, Sulu, Sulawesi in summer

The average salinity of the Sea of ​​Japan, approximately 34.1‰, is slightly lower than the average salinity of the waters of the World Ocean.

In winter, the highest salinity of the surface layer (about 34.5‰) is observed in the south. The lowest surface salinity (about 33.8‰) is observed along the southeastern and southwestern coasts, where heavy precipitation causes some desalination. In most of the sea, salinity is 34.l‰. In spring, in the north and northwest, desalination of surface water occurs due to melting ice, and in other areas it is associated with an increase in precipitation. Salinity remains relatively high (34.6-34.7‰) in the south, where at this time the influx of saltier waters entering through the Korea Strait increases. In summer, the average salinity on the surface varies from 32.5‰ in the north of the Tatar Strait to 34.5‰ off the coast of the island. Honshu.

In the central and southern regions of the sea, precipitation significantly exceeds evaporation, which leads to desalination of surface waters. By autumn, the amount of precipitation decreases, the sea begins to cool, and therefore the salinity on the surface increases.

The vertical variation of salinity is generally characterized by small changes in its values ​​along the depth.

In winter, most of the sea experiences a uniform salinity from surface to bottom, equal to approximately 34.1‰. Only in coastal waters is there a weakly expressed minimum salinity in the surface horizons, below which the salinity increases slightly and remains almost the same to the bottom. At this time of year, vertical changes in salinity in most of the sea do not exceed 0.6-0.7‰, and in its central part they do not reach

Spring-summer desalination of surface waters forms the main features of the summer vertical distribution of salinity.

In summer, minimal salinity is observed on the surface as a result of noticeable desalination of surface waters. In subsurface layers, salinity increases with depth, creating noticeable vertical salinity gradients. The maximum salinity at this time is observed at horizons of 50-100 m in the northern regions and at horizons of 500-1500 m in the southern regions. Below these layers, salinity decreases slightly and remains almost unchanged to the bottom, remaining within the range of 33.9-34.1‰. In summer, the salinity of deep waters is 0.1‰ less than in winter.

Water circulation and currents

The density of water in the Sea of ​​Japan depends mainly on temperature. The highest density is observed in winter, and the lowest in summer. In the northwestern part of the sea the density is higher than in the southern and southeastern parts.

In winter, the surface density is quite uniform throughout the sea, especially in its northwestern part.

In spring, the uniformity of surface density values ​​is disrupted due to different heating of the upper layer of water.

In summer, horizontal differences in surface density values ​​are greatest. They are especially significant in the area of ​​mixing waters with different characteristics. In winter, the density is approximately the same from surface to bottom in the northwestern part of the sea. In the southeastern regions, the density increases slightly at horizons of 50-100 m; deeper and to the bottom it increases very slightly. The maximum density is observed in March.

In summer in the northwest, the waters are noticeably interlayered in density. It is small on the surface, rises sharply at horizons of 50-100 m and increases more gradually deeper to the bottom. In the southwestern part of the sea, the density increases noticeably in the subsurface (up to 50 m) layers, at horizons of 100-150 m it is quite uniform, below the density increases slightly to the bottom. This transition occurs at horizons of 150-200 m in the northwest and at horizons of 300-400 m in the southeast of the sea.

In autumn, the density begins to level out, which means a transition to winter view density distribution with depth. Spring-summer density stratification determines a fairly stable state of the waters of the Sea of ​​Japan, although it is expressed to varying degrees in different areas. In accordance with this, more or less favorable preconditions are created in the sea for the emergence and development of mixing.

Due to the predominance of winds of relatively low strength and their significant intensification during the passage of cyclones under conditions of water stratification in the north and northwest of the sea, wind mixing penetrates here to horizons of about 20 m. In the less stratified waters of the southern and southwestern regions, the wind mixes the upper layers to the horizons 25-30 m. In autumn, stratification decreases and winds increase, but at this time of year the thickness of the upper homogeneous layer increases due to density mixing.

Autumn-winter cooling, and in the north, ice formation, cause intense convection in the Sea of ​​Japan. In its northern and northwestern parts, as a result of rapid autumn cooling of the surface, convective mixing develops, which covers deep layers within a short time. With the onset of ice formation, this process intensifies, and in December convection penetrates to the bottom. At great depths, it extends to horizons of 2000-3000 m. In the southern and southeastern regions of the sea, cooled to a lesser extent in autumn and winter, convection extends mainly to horizons of 200 m. In areas of sharp changes in depth, convection is enhanced by the sliding of water along slopes, as a result of which density mixing penetrates to horizons of 300-400 m. Below mixing is limited by the density structure of water, and ventilation of the bottom layers occurs due to turbulence, vertical movements and other dynamic processes.

On the roadstead of Tokyo port

The nature of the circulation of sea waters is determined not only by the influence of winds acting directly above the sea, but also by the circulation of the atmosphere above northern part Pacific Ocean, since the strengthening or weakening of the influx of Pacific waters depends on it. In summer, the southeast monsoon promotes increased water circulation due to the flow of large quantity water. In winter, the persistent northwest monsoon prevents the flow of water into the sea through the Korea Strait, causing weakening water circulation.

Through the Korea Strait, the waters of the western branch of the Kuroshio, which passed through the Yellow Sea, enter the Sea of ​​Japan and spread in a wide stream to the northeast along the Japanese islands. This flow is called the Tsushima Current. In the central part of the sea, the Yamato Rise divides the flow of Pacific waters into two branches, forming a divergence zone, which is especially pronounced in the summer. In this zone, deep waters rise. After going around the hill, both branches connect in an area located in the northwest of the Noto Peninsula.

At a latitude of 38-39°, a small flow separates from the northern branch of the Tsushima Current to the west, towards the Korea Strait, and turns into a countercurrent along the coast of the Korean Peninsula. The bulk of the Pacific waters are carried out from the Sea of ​​Japan through the Sangarsky and La Perouse straits, while some of the waters, having reached the Tatar Strait, give rise to the cold Primorsky Current, moving south. South of Peter the Great Bay, the Primorsky Current turns east and merges with the northern branch of the Tsushima Current. A small part of the water continues to move south to Korea Bay, where it flows into the countercurrent formed by the waters of the Tsushima Current.

Thus, moving along the Japanese Islands from south to north, and along the coast of Primorye - from north to south, the waters of the Sea of ​​Japan form a cyclonic gyre centered in the northwestern part of the sea. In the center of the gyre, rising waters are also possible.

In the Sea of ​​Japan, two frontal zones are distinguished - the main polar front, formed by the warm and salty waters of the Tsushima Current and the cold, less saline waters of the Primorsky Current, and the secondary front, formed by the waters of the Primorsky Current and coastal waters, which in summer have a higher temperature and lower salinity than the waters of the Primorsky Current. In winter, the polar front passes slightly south of the parallel of 40° N, and near the Japanese Islands it runs approximately parallel to them almost to the northern tip of the island. Hokkaido. In summer, the location of the front is approximately the same, it only moves slightly to the south, and off the coast of Japan - to the west. The secondary front passes near the coast of Primorye, approximately parallel to them.

The tides in the Sea of ​​Japan are quite distinct. They are created mainly by the Pacific tidal wave entering the sea through the Korea and Sangar Straits.

The sea experiences semi-diurnal, diurnal and mixed tides. In the Korea Strait and in the north of the Tatar Strait there are semi-diurnal tides, on the eastern coast of Korea, on the coast of Primorye, near the islands of Honshu and Hokkaido - diurnal tides, in Peter the Great and Korean Gulfs - mixed.

The nature of the tide corresponds tidal currents. In open areas of the sea, semidiurnal tidal currents with speeds of 10-25 cm/s are mainly observed. Tidal currents in the straits are more complex, where they have very significant speeds. Thus, in the Sangar Strait, tidal current speeds reach 100-200 cm/s, in the La Perouse Strait - 50-100, in the Korea Strait - 40-60 cm/s.

The greatest level fluctuations are observed in the extreme southern and northern regions of the sea. At the southern entrance to the Korea Strait, the tide reaches 3 m. As you move north, it quickly decreases and already at Busan it does not exceed 1.5 m.

In the middle part of the sea the tides are low. Along eastern shores On the Korean Peninsula and Soviet Primorye, before entering the Tatar Strait, they are no more than 0.5 m. The tides are of the same magnitude off the western coasts of Honshu, Hokkaido and Southwestern Sakhalin. In the Tatar Strait, the tide height is 2.3-2.8 m. In the northern part of the Tatar Strait, the tide heights increase, which is determined by its funnel-shaped shape.

In addition to tidal fluctuations, seasonal level fluctuations are well expressed in the Sea of ​​Japan. In summer (August - September) the maximum rise in level is observed on all shores of the sea; in winter and early spring (January - April) the minimum level is observed.

In the Sea of ​​Japan, surge level fluctuations are observed. During the winter monsoon off the western coast of Japan, the level can rise by 20-25 cm, and off the mainland coast it can drop by the same amount. In summer, on the contrary, off the coast of North Korea and Primorye the level rises by 20-25 cm, and near Japanese shores decreases by the same amount.

Strong winds caused by the passage of cyclones and especially typhoons over the sea develop very significant waves, while monsoons cause less strong waves. In the northwestern part of the sea, northwestern waves predominate in autumn and winter, and eastern waves prevail in spring and summer. Most often, disturbances with a force of 1-3 points are observed, the frequency of which varies from 60 to 80% per year. In winter, strong waves prevail - 6 points or more, the frequency of which is about 10%.

In the southeastern part of the sea, thanks to the stable northwest monsoon, waves from the northwest and north develop in winter. In summer, weak, most often southwesterly, waves prevail. The largest waves have a height of 8-10 m, and during typhoons, the maximum waves reach a height of 12 m. Tsunami waves are observed in the Sea of ​​Japan.

The northern and northwestern parts of the sea, adjacent to the mainland coast, are covered with ice annually for 4-5 months, the area of ​​which occupies about 1/4 of the entire sea.

Ice cover

The appearance of ice in the Sea of ​​Japan is possible as early as October, and last ice lingers in the north sometimes until mid-June. Thus, the sea is completely ice-free only during the summer months - July, August and September.

The first ice in the sea forms in closed bays and bays of the mainland coast, for example in Sovetskaya Gavan Bay, De-Kastri and Olga Bays. In October - November, ice cover mainly develops within bays and bays, and from late November - early December, ice begins to form in the open sea.

At the end of December, ice formation in coastal and open sea areas extends to Peter the Great Bay.

Fast ice is not widespread in the Sea of ​​Japan. It forms first in the bays of De-Kastri, Sovetskaya Gavan and Olga; in the bays of Peter the Great Bay and Posyet it appears after about a month.

Every year, only the northern bays of the mainland coast freeze completely. South of Sovetskaya Gavan, the fast ice in the bays is unstable and can break up repeatedly during the winter. In the western part of the sea, floating and stationary ice appears earlier than in the eastern part; it is more stable. This is explained by the fact that the western part of the sea in winter is under the predominant influence of cold and dry air masses, spreading from the mainland. In the east of the sea, the influence of these masses weakens significantly, and at the same time the role of warm and humid marine air masses increases. The ice cover reaches its greatest development around mid-February. From February to May, conditions favorable for ice melting (in situ) are created throughout the sea. In the eastern part of the sea, ice melting “begins earlier and occurs more intensely than at the same latitudes in the west.

Ice cover in the Sea of ​​Japan varies significantly from year to year. There may be cases when the ice cover in one winter is 2 times or more greater than the ice cover in another.

Economic importance

Inhabitants of the Sea of ​​Japan

The fish population of the Sea of ​​Japan includes 615 species. The main commercial species of the southern part of the sea include sardine, anchovy, mackerel, and horse mackerel. In the northern regions, the main fish caught are mussels, flounder, herring, greenling and salmon. In summer, tuna, hammerfish, and saury penetrate into the northern part of the sea. The leading place in the species composition of fish catches is occupied by pollock, sardine and anchovy.

The Sea of ​​Japan is considered one of the largest and deepest seas in the world. It is a marginal sea of ​​the Pacific Ocean.

Origin

The first information about this sea was received from Chinese sources in the 2nd century BC. Historically, it is believed that this reservoir was formed as a result of the melting of a glacier and rising water levels in the world's oceans.

Historical events

In the 14th-16th centuries, pirates seized power at sea. All maritime trade was under their control. From 1603 to 1867, the Sea of ​​Japan was one of the busiest transport links and the main route of entry for the Dutch and Korean embassies.

Sea of ​​Japan on the map photo

The Sea of ​​Japan witnessed the Russo-Japanese War (1901-1902). Today, the Sea of ​​Japan is an important domestic and international transport artery.

Characteristic

Main characteristics of the Sea of ​​Japan:

• Area 1,062,000 square km
• Average sea depth: 1536 m.
• Greatest depth: 3742 m.
• Salinity: 34-35 ‰.
• Length: from north to south 2,255 km, from west to east about 1,070 km.
• In winter, part of the Sea of ​​Japan freezes - the Russian coastal side, but the ice can break up periodically;
• Average annual temperature: in the north 0-12C, in the south 17-26C.

shore of the Sea of ​​Japan photo

Currents

The main current of the Sea of ​​Japan is the Tsushima, whose width is approximately 200 km. This current contains surface and intermediate water masses. In addition, the following cold currents are observed in the Sea of ​​Japan:

• Limanskoye, moving at low speed to the southwest;
• North Korean, going south;
• Coastal, or cold current, going to the central part.

Japanese Sea. Primorsky Krai photo

These cold currents form a counterclockwise circulation. The warm Kuroshio Current prevails in the southern part of the sea.

What rivers flow into

Few rivers flow into the Sea of ​​Japan, most of them are mountainous. Let us note the largest of them:

• Partisan;
• Tumnin;
• Samarga;
• Rudnaya.

Where does the Sea of ​​Japan flow into?

Sea waters enter through the straits:

• through the Nevelsky Strait to the Sea of ​​Okhotsk;
• through the Sangar Strait to the Pacific Ocean;
• through the Korea Strait into the East China Sea.

Japanese Sea. storm photo

Climate

The climate of the sea is monsoon, temperate. The western and northern parts of the sea are much colder than the southern and eastern. The temperature difference reaches +27 C. Hurricanes and typhoons often pass over the sea surface.

Despite the fact that the sea is separated from the ocean by the Japanese islands and Sakhalin, storms and hurricanes often rage in the northern part of the sea, especially in autumn. Such exposure can last up to three days, and the waves reach 12 meters in height. The Siberian anticyclone brings such weather. For this reason, the Sea of ​​Japan is not very calm for shipping.

Japanese Sea. port of Vladivostok photo

In November, the northern part of the sea is covered with ice, and in March-April the ice breaks up. In summer the weather is cloudy and weak monsoon winds from the southeast prevail.

Relief

The bottom topography of the Sea of ​​Japan is divided into:

• the northern part (a wide trench that narrows and rises to the north);
• the central part (a deep closed basin, elongated in a northeast direction);
• the southern part (the terrain is complex, alternating shallow water with troughs).

Shores of this sea mostly mountainous. Low-lying coastlines are extremely rare. The coastline is quite flat on Sakhalin. The shores of Primorye are more rugged.

underwater world of the Sea of ​​Japan photo

Cities and ports

Let us note the more significant Russian port cities located in the Sea of ​​Japan:

• Vladivostok;
• Nakhodka;
• Oriental;
• Sovetskaya Gavan;
• Vanino;
• Shakhtersk

Flora and fauna

Brown algae and kelp grow abundantly along the seashores. The Sea of ​​Japan is very rich in fish fauna due to the abundance of oxygen and food. Approximately 610 species of fish live here. The main types of fish fauna are:

• In the southern part of the sea - anchovy, sardine, horse mackerel, mackerel.
• In the northern regions - flounder, herring, salmon, greenling, mussels, saury, hammerfish, tuna.

Fishing in the Sea of ​​Japan lasts all year round. IN this region There are 6 species of seals, 12 species of sharks that are not dangerous to humans, squid and octopuses.

Few people know the following Interesting Facts about the Sea of ​​Japan:

• Residents of North Korea call this sea the Korean East Sea;
• Residents South Korea- Eastern Sea.
• Here you can meet representatives of 31 orders of fish out of 34 orders existing in the world;
• The Sea of ​​Japan leads in fish diversity among all the seas of the Russian Federation;
• A small jellyfish lives in the algae of the sea, capable of infecting the central nervous system, and with repeated contact its poison can be fatal. Famous resorts not here, but the Sea of ​​Japan is very important for the trade and economy of several countries, including Russia.