The direction of currents is influenced by the force of the Earth's rotation: in the Northern Hemisphere, currents move to the right, in the Southern Hemisphere, to the left.
A current is called warm if its temperature is warmer than the temperature of the surrounding waters. otherwise, the current is called cold.
Density flows are caused by pressure differences, which are caused by uneven density distribution sea water. Density currents are formed in the deep layers of seas and oceans. A striking example Density currents are the warm Gulf Stream.
Wind currents are formed under the influence of winds, as a result of the frictional forces of water and air, turbulent viscosity, pressure gradient, deflecting force of the Earth's rotation and some other factors. Wind currents are always surface currents: northern and southern trade winds, the current of the western winds, the inter-trade winds of the Pacific and Atlantic.
1) The Gulf Stream is a warm sea current in the Atlantic Ocean. In a broad sense, the Gulf Stream is a system of warm currents in the North Atlantic Ocean from Florida to the Scandinavian Peninsula, Spitsbergen, Barents Sea and the Arctic Ocean.
Thanks to the Gulf Stream, European countries adjacent to the Atlantic Ocean have a milder climate than other regions at the same latitude: masses warm water They heat the air above them, which is carried by westerly winds to Europe. Deviations of air temperature from the average latitude values in January reach 15-20 °C in Norway, and more than 11 °C in Murmansk.
2) Peruvian Current - cold surface current in the Pacific Ocean. Moves from south to north between 4° and 45° south latitude along western shores Peru and Chile.
3)Canary Current- cold and, subsequently, moderately warm sea current in the northeastern part Atlantic Ocean. Directed from north to south along the Iberian Peninsula and North-West Africa as a branch of the North Atlantic Current.
4) The Labrador Current is a cold sea current in the Atlantic Ocean, flowing between the coast of Canada and Greenland and rushing south from the Baffin Sea to the Newfoundland Bank. There it meets the Gulf Stream.
5) North Atlantic Current - powerful warm ocean current, is the northeastern continuation of the Gulf Stream. Starts at the Great Bank of Newfoundland. West of Ireland the current divides into two parts. One branch (the Canary Current) goes south and the other goes north along the coast of northwestern Europe. The current is believed to have a significant influence on the climate in Europe.
6) The Cold California Current emerges from the North Pacific Current, moves along the coast of California from northwest to southeast, and merges in the south with the North Trade Wind Current.
7) Kuroshio, sometimes the Japan Current, is a warm current off the southern and eastern coasts of Japan in the Pacific Ocean.
8) The Kuril Current or Oyashio is a cold current in the northwest Pacific Ocean, which originates in the waters of the Arctic Ocean. In the south, near the Japanese Islands, it merges with Kuroshio. It flows along Kamchatka, the Kuril Islands and the Japanese islands.
9) The North Pacific Current is a warm ocean current in the North Pacific Ocean. It is formed as a result of the merger of the Kuril Current and the Kuroshio Current. Moves from the Japanese islands to the shores North America.
10) Brazil Current - a warm current of the Atlantic Ocean off the eastern shores South America, directed to the southwest.
P.S. To understand where the different currents are, study a set of maps. It will also be useful to read this article
Currents have very important for navigation, influencing the speed and direction of the vessel. Therefore, in navigation it is very important to be able to take them into account correctly (Fig. 18.6).
To choose the most profitable and safe routes when sailing near the coast and in the open sea, it is important to know the nature, directions and speed of sea currents.
When sailing by dead reckoning sea currents can have a significant impact on its accuracy.
Sea currents - movement water masses in the sea or ocean from one place to another. The main causes of sea currents are wind, Atmosphere pressure, tidal phenomena.
Sea currents are divided into the following types
1. Wind and drift currents arise under the influence of wind due to the friction of moving air masses on the sea surface. Long-lasting, or prevailing, winds cause movement of not only the upper, but also deeper layers of water, and form drift currents.
Moreover, drift currents caused by trade winds (constant winds) are constant, while drift currents caused by monsoons (variable winds) change both direction and speed throughout the year. Temporary, short-lived winds cause wind currents that are variable in nature.
2. Tidal currents are caused by changes in sea level due to high and low tides. In the open sea, tidal currents constantly change their direction: in the northern hemisphere - clockwise, in the southern hemisphere - counterclockwise. In straits, narrow bays and off the coast, currents at high tide are directed in one direction, and at low tide - in the opposite direction.
3. Sewage currents are caused by a rise in sea level in certain areas as a result of influx fresh water from rivers, fallout large quantity precipitation, etc.
4. Density currents arise due to the uneven distribution of water density in the horizontal direction.
5. Compensatory currents arise in a particular area to replenish the loss of water caused by its runoff or overflow.
Rice. 18.6. Currents of the World Ocean
The Gulf Stream, the most powerful warm current in the world's oceans, runs along the coast of North America in the Atlantic Ocean, and then it deviates from the shore and splits into a series of branches. The northern branch, or North Atlantic Current, flows to the northeast. The presence of the North Atlantic Warm Current explains the relatively mild winter on the coast Northern Europe, as well as the existence of a number of ice-free ports.
In the Pacific Ocean, the Northern Trade Wind (equatorial) Current begins off the coast Central America, crosses Pacific Ocean with an average speed of about 1 knot, and near the Philippine Islands it divides into several branches.
Main branch of the Northern trade wind current passes along the Philippine Islands and follows to the northeast called Kuroshio, which is the second powerful warm current of the World Ocean after the Gulf Stream; its speed is from 1 to 2 knots and even at times up to 3 knots.
Near the southern tip of Kyushu Island, this current splits into two branches, one of which, the Tsushima Current, heads into the Korea Strait.
The other, moving northeast, becomes the North Pacific Current, crossing the ocean to the east. The cold Kuril Current (Oyashio) follows Kuroshio along the Kuril ridge and meets it approximately at the latitude of the Sangar Strait.
The current of westerly winds off the coast of South America is divided into two branches, one of which gives rise to the cold Peruvian Current.
IN Indian Ocean The southern trade wind (equatorial) current near the island of Madagascar is divided into two branches. One branch turns south and forms the Mozambique Current, the speed of which is from 2 to 4 knots.
At the southern tip of Africa, the Mozambique Current gives rise to the warm, powerful and persistent Agulhas Current, average speed which is more than 2 knots, and the maximum is about 4.5 knots.
In Northern Arctic Ocean The bulk of the surface layer of water moves clockwise from east to west.
NASA specialists have created a new map of the world's ocean currents. Its difference from all previous ones is interactivity - anyone can independently look at all the stable water flows and determine the temperature nature of the flow.
Did you know that ocean water is heterogeneous? It is logical that closer to the surface it is warmer than at depth. However, not everyone knows that the volume of salt in ocean water, with rare exceptions, is inversely proportional to the depth at which this water is located - the deeper, the fresher it is. However, there are exceptions to this rule. For example, in the Arctic and Antarctic, deep waters are also saturated with salt - ice layers that penetrate to great depths contain particles of surface salt evaporation, enriching the entire water layer with them.
Upper layer ocean water driven by stable air currents. So the map ocean currents generally identical to the sea wind map.
Unique online map
A unique map with which you can examine in detail the currents of all the oceans of the world
The model was developed to demonstrate the mechanism of thermal circulation in the world's waters. However, the map is not absolutely accurate - in order to better demonstrate the difference between surface and deep water flows, in certain areas the depth indicator is somewhat overestimated in relation to the real one.
Animation component new card simulated NASA scientists at the Goddard Space Flight Center laboratory.
Comparative current contour map
Below is a classic contour map currents of the world's oceans in Russian, which schematically displays all the main cold and warm currents world ocean. The arrows indicate the direction of movement, and the color indicates the temperature characteristics of the water - whether a particular current is warm or cold.
Europe's largest spent waste storage facility nuclear fuel(SNF), the most radiation hazardous object of the era cold war— a lot of frightening definitions have been invented for the coastal technical base in Andreeva Bay, not far from Zaozersk. Recently, an international seminar (already the fifth in a row) was held in Murmansk on the history current state and the prospects for the rehabilitation of the USSR-era nuclear legacy accumulated in Andreeva Bay. Its organizers were the state corporation Rosatom, the public council created under it and the environmental association Bellona.
Containers for storing spent nuclear fuel at the storage site.
Dangerous current situation
— Andreeva Guba has always served the interests of Navy. This is the largest coastal technical base, where the recharging of all nuclear power plants has been going on for decades. submarines Northern Fleet. The first reloading was carried out in 1961, recalls captain of the first rank of the reserve, Navy veteran Vyacheslav Perovsky.
Moreover, since nuclear technologies were just being developed at that time, many mistakes were made, according to Perovsky. Thus, the canisters with spent nuclear fuel were stored in two pools under protective layer water in the so-called building No. 5. Sometimes, during loading, the cover was torn from the suspension and simply fell to the bottom of the pool, simultaneously damaging other covers. So there were just rubble at the bottom.
“The fatal miscalculation was in these pools themselves,” adds Vyacheslav Perovsky, “they were not needed at all.” The active zones of the submarines remained cold and did not require cooling. At the same time, the concrete walls of the pools were sheathed with ordinary black steel, which simply rusted under the influence of water...
And in 1982 an accident occurred. A crack formed in the lining of the right basin, radioactive water began to flow into the ground, and then into the stream, which carried it into Andreeva Bay and ultimately into the Barents Sea. In September, the leak reached 30 tons per day. Appeared real threat that because of the naked upper parts spent fuel assemblies (SFAs) will result in serious exposure of personnel. And the pollution of the adjacent water area was alarming.
It was decided to protect the right pool with a ceiling made of concrete, iron and lead. And then drain it. Work began in November. But here, too, miscalculations were made. The heavy structure caused the entire building to tilt, causing the left pool to leak. The right one was nevertheless blocked, and by that time the water had flowed out of it. Up to 3 tons per day were lost from the left pool, and water was pumped into it continuously through fire hoses.
In February 1983, a Ministry of Defense commission banned the operation of the storage facility. It was decided to transfer the spent fuel into three empty tanks, which were originally intended to store liquid radioactive waste, as soon as possible. They were urgently converted into dry storage units (DSB). The main part of the spent fuel was reloaded into them, some was sent to the Mayak production association in Chelyabinsk region, several damaged covers remained in building No. 5. And only in 1989 were all the covers unloaded from it.
The environmental consequences of the accident were quite significant.
— The groundwater in the BTB area in Andreeva Bay still have mutagenic activity,” states Natalia Shandala, Deputy Director General of the Burnazyan Federal Medical and Biological Center.
The secret has become clear
For many years, information about the accident at a secret military base was simply kept silent. And this despite the fact that Greenpeace, Bellona and a number of others environmental organizations, as they say, sounded the alarm.
“The information breakthrough occurred in 1993,” says Alexander Nikitin, chairman of the board of the Bellona environmental human rights center in St. Petersburg.
Alexander Nikitin.
It was then that the authoritative Norwegian newspaper Aftenposten wrote about Andreeva Bay. It was simply unthinkable to remain silent about the situation any longer. The final turning point, according to Nikitin, came a little later, in 1998, when Russian Prime Minister Sergei Kiriyenko signed Resolution No. 518, which transferred the functions of coordinating work on the comprehensive dismantlement of nuclear submarines from the Ministry of Defense to the Russian Atomic Ministry. Two years later, coastal operations were also transferred to the same department. technical bases Navy, including Andreeva Bay.
“This was one of the most problematic objects of the Navy,” says Alexander Nikitin.
Over the next fifteen years, says the secretary public council on questions safe use atomic energy V Murmansk region Sergei Zhavoronkin, in terms of establishing public control over the situation, progress has been made huge way- from “preventing ecological tourism on nuclear dangerous objects”(at the beginning there were also such statements addressed to social activists and environmentalists) until full interaction. Evidence of the latter is the last seminar organized jointly by Rosatom by social activists and environmentalists.
The whole world piled on
But let's return to the chronicle of events. The next breakthrough was the acceptance of international assistance.
— In 2001, a seminar was held in Idaho Falls (USA). In addition to Russia, seven more countries took part in it. The main goal the meeting was assessed environmental problems BTB in Andreeva Bay. Experts stated that it is necessary to begin the rehabilitation of the base with the infrastructure,” notes the director International Center By environmental safety, main Researcher JSC "NIKIET named after Dollezhal" Albert Vasiliev.
And Norway was the first to provide assistance to Russia in this matter. Over twenty years, from 1996 to 2016, it reminds Chief Engineer provincial government of the province of Finnmark Per-Einar Fiskebäck, Northern Kingdom allocated 250 million crowns for the rehabilitation of Andreeva Bay. An access road and administrative building, issues with the power supply of the facility were resolved, a physical protection system was created (perimeter and security building), and so on, including a beacon for safe navigation in the waters of Andreeva Bay for ships technical support"Serebryanka" and "Rossita".
Director of the Andreeva Bay branch of the SevRAO SWC, Alexander Krasnoshchekov.
IN total During the preparation of the infrastructure at the base, two dozen “clean” facilities were dismantled, and 17 new ones were built.
— The objects were ranked according to the degree of danger emanating from them. For maximum objectivity, assessments were used various methods, says a representative of the Institute of Problems safe development nuclear energy RAS Mikhail Kobrinsky. — The main problems, of course, were building No. 5 and three dry storage tanks. There, the concentration of radionuclides per unit volume was much higher than anywhere else on the base.
“About a hundred active zones of nuclear submarines are stored there - 22 thousand assemblies,” adds the head of the coordination and implementation department international programs State Corporation "Rosatom" Anatoly Grigoriev. “It was almost impossible to even approach the BSH to clarify their condition. To handle spent nuclear fuel and its subsequent removal, it was necessary to create a special production facility. The key question was the construction of a shelter building over three dry storage units.
“Our position was the following: it is better to do this work longer, but safer. To reduce as much as possible possible risks, emphasizes the representative government controlled Norway on Nuclear and radiation safety Ingar Amundsen.
Following Norway, the United Kingdom joined in helping. With British money, building No. 5 is being rehabilitated (the work has not yet been completed), environmentally friendly buildings and old technological equipment of the berth have been dismantled (without its reconstruction, spent nuclear fuel simply cannot be removed from the base), a landfill for construction waste and a site for transported construction materials have been built, cable networks have been updated and so on.
Sweden, Italy and the EU countries as a whole also made a significant contribution to the rehabilitation of the BTB in Andreeva Bay.
Almost ready for pickup
Above the BSH tanks, says CEO JSC "NIPTB "Onega" Konstantin Kulikov, bioprotection elements were installed to minimize the impact on personnel. This measure significantly improved the radiation situation, which made it possible to begin the construction of a shelter building.
The transport and technological scheme of the upcoming removal of spent nuclear fuel from the base is laid out for the seminar participants on the shelves by an expert from the department of programs of the international technical assistance Federal Center Nuclear and Radiation Safety Pavel Nasonov and Chief Engineer of the Center for Disposal Management radioactive waste Andreeva Bay branch of the SevRAO SWC (as the base is officially called today) Igor Kazakov.
Without details, it is as follows: a technological vessel stands at the berth, and an empty container is reloaded from it by crane onto a special trolley, which delivers it to a covered storage area. From there, the transporter transports the container to the shelter building, where spent fuel assemblies removed from the opened BSH tank are loaded into it. After which the container is sealed and reverse order delivered to the ship. And so container after container, flight after flight...
Almost everything is ready. An overhead crane for reloading containers at the pier was delivered in 2014, it was installed in 2015 and went into operation in July of the same year. The transport trolley was tested in December 2015 and put into operation in July 2016. The storage area itself (building No. 151) was commissioned this summer. There are already 14 empty containers here for testing the entire scheme in the so-called cold mode. A special transporter arrived at the work site in the spring of 2016.
The shelter building above the dry storage tanks (building No. 153) is not yet completely ready. The zero cycle and installation of metal structures have already been completed, cranes have been installed above the tanks. The reloading unit is currently being installed. Overall, the work is 75 percent complete. Comprehensive tests are due to take place in December. And in June next year, the removal of spent nuclear fuel will begin. And then, if everything goes according to plan, in a few decades there will be an ordinary green lawn on the site of the former secret Navy base.