7. The structure of the waters of the oceans.

Horizontal and vertical structure of the waters of the World Ocean. The concept of water masses and ocean fronts. Mechanisms of formation of water masses. Methods for identifying water masses and oceanic fronts. Transformation of water masses. Classification of water masses and oceanic fronts.

Vertical structural zones of the water column of the World Ocean. Oceanic troposphere, oceanic stratosphere.

8. Dynamics of the waters of the World Ocean.

The main forces acting in the ocean. Ocean currents: concept, classifications. Theories of the genesis of currents in the World Ocean.

The main circulation systems in the World Ocean. deep circulation. Convergence and Divergence. Ocean vortices.

The emergence and development of waves in the ocean. Wave classification. Wave elements. Assessment of the degree of wind waves. Behavior of wind waves near coasts of various types. Seishi, tsunami, internal waves. Waves in cyclones.

Fundamentals of the classical theory of sea waves (the theory of waves for a deep sea, the theory of waves for a shallow sea). Wave energy balance equation. Methods for calculating wind waves.

Physical patterns of tide formation. Static theory of tides. Dynamic theory of tides. Classification and characteristics of tides. Tide inequality. Tidal phenomena in the ocean.

9. Ocean level.

The concept of a level surface. Periodic and non-periodic level fluctuations.

Intermediate level: concept, types, methods of definition. Hydrometeorological causes of level fluctuations. Dynamic causes of level fluctuations.

Water balance of the World Ocean and its components.

10. Sea ice in the climate system.

Factors in the formation and melting of sea ice. The current state of the sea ice cover.

Sea ice balance equation.

Glacial-interglacial fluctuations in the Pleistocene. Intra-secular changes in the distribution of sea ice. Instability threshold. Self-oscillations in the "ocean - atmosphere - glaciation" system.

Sea ice as a factor in climate change. Sea ice and atmospheric circulation.

11. Ocean-atmosphere system.

General characteristics of the processes of interaction between the ocean and the atmosphere. The scale of interaction. Radiation balance of the ocean. Heat transfer in the ocean-atmosphere system and its climate-forming significance. Ocean heat balance equation and its analysis.

Moisture exchange in the ocean-atmosphere system. Salt balance and its relationship with water balance. Gas exchange in the ocean-atmosphere system.

The concept of the hydrological cycle. Patterns of formation of the hydrological cycle. Basic Equations Describing the Atmospheric Link of the Hydrological Cycle. Dynamic interaction of ocean and atmosphere.

Influence of the ocean on climate and weather-forming processes in the atmosphere.

EDUCATIONAL AND METHODOLOGICAL CARD OF THE EDUCATIONAL DISCIPLINE

INFORMATIONAL AND METHODOLOGICAL PART

Literature

Main

Vorobyov V.N., Smirnov N.P. General Oceanology. Part 2. Dynamic processes. - St. Petersburg: ed. RSGM, 1999. - 236 p.

Egorov N.I. Physical oceanography. - L.: Gidrometeoizdat, 1974. - 456 p.

Zhukov L.A. General oceanology: (textbook for universities in the specialty "Oceanology"). - L .: Gidrometeoizdat, 1976. - 376 p.

Malinin V.N. General Oceanology. Part 1. Physical processes. - St. Petersburg: ed. RSGM, 1998. - 342 p.

Neshiba S. Oceanology. Modern ideas about the liquid shell of the Earth: Per. from English. – M.: Mir, 1991. – 414 p.

Shamraev Yu.I., Shishkina L.A. Oceanology. - L.: Gidrometeoizdat, 1980. - 382 p.

Additional

Alekin O.A., Lyakhin Yu.I. Ocean Chemistry. - L.: Gidrometeoizdat, 1984. - 344 p.

Bezrukov Yu.F. Level fluctuations and waves in the oceans. Tutorial. - Simferopol, 2001. - 52 p.

Bezrukov Yu.F. Oceanology. Part 1. Physical phenomena and processes in the ocean. - Simferopol, 2006. - 162 p.

Davydov L.K., Dmitrieva A.A., Konkina N.G. General hydrology. - L.: Gidrometeoizdat, 1973. - 464 p.

Dolganovsky A.M., Malinin V.N. Earth's hydrosphere. - St. Petersburg: Gidrometeoizdat, 2004. - 632 p.

Doronin Yu.P. Interaction between the atmosphere and the ocean. - L.: Gidrometeoizdat, 1981. - 288 p.

Doronin Yu.P. Physics of the ocean. - St. Petersburg: ed. RSGM, 2000. - 340 p.

Zakharov V.F., Malinin V.N. Sea ice and climate. - St. Petersburg: Gidrometeoizdat, 2000. - 92 p.

Kagan B.A. Interaction between the ocean and the atmosphere. - St. Petersburg: Gidrometeoizdat, 1992. - 335 p.

Lappo S.S., Gulev S.K., Rozhdestvensky A.E. Large-scale thermal interaction in the ocean-atmosphere system and energy-active regions of the World Ocean. - L.: Gidrometeoizdat, 1990. - 336 p.

Malinin V.N. Moisture exchange in the ocean-atmosphere system. - St. Petersburg: Gidrometeoizdat, 1994. - 198 p.

Monin A.S. Hydrodynamics of the atmosphere and the ocean and the earth's interior. - St. Petersburg: Gidrometeoizdat, 1999. - 524 p.

Peri A.H., Walker J.M. The ocean-atmosphere system. - L.: Gidrometeizdat, 1979. - 193 p.

Eisenberg D., Kautsman V. Structure and properties of water. - L.: Gidrometeoizdat, 1975. - 280 p.

List of used diagnostic tools

oral survey,

abstract protection,

verification of settlement and graphic works,

Approximate list of tasks of the SMR

Theme "Methods of oceanological measurements".

Task 1. Draw in a workbook and prepare a brief description of the principle of operation of the main hydrological instruments (radiometer, bathometer, STD probe, oceanographic pressure gauges and thermometers, instruments for seabed research and biological research).

"Cruise Observations in the World Ocean",

"Stationary Observations in the World Ocean",

"Remote Observations of the World Ocean",

"Methods of direct oceanological measurements",

"Methods of indirect oceanological measurements",

"Methods for improving the quality of oceanological measurements",

"The main types of processing of oceanological observations",

"Mathematical modeling of oceanological processes",

"Application of GIS technologies for solving oceanological problems",

"Oceanological databases".

Theme "Gravitational, magnetic and electric fields of the ocean".

Task 1. Construct graphs that reflect the dependence of the electrical conductivity of sea water: a) on salinity, b) on temperature, c) on pressure.

Task 2. Put the axes of magnetic anomalies of the mid-ocean ridges on the contour map of the World Ocean.

Theme "Anomalies of physical properties of water".

Task 1. Construct graphs of the dependence of freezing temperatures and the highest density of water on salinity and analyze them in relation to sea and brackish waters.

Task 2. Independently, having worked through literary sources, prepare and fill in the table "Change in the physical properties of water during isotopic substitution."

Theme "Water balance of the World Ocean and its components".

Task 1. Build and analyze the table "Average latitudinal distribution of the components of the Earth's water balance."

Task 2. Prepare in text form an analysis "Comparative characteristics of the components of the water balance of the oceans" (according to the options: Atlantic - Pacific, Pacific - Indian, Atlantic - Indian, Arctic - Indian)

Theme "Horizontal structure of the waters of the oceans".

Task 1. Put the main oceanic and dynamic fronts of the World Ocean on the contour map.

Task 2. According to the task given by the teacher (according to options), carry out a graphical analysis of T, S-curves of the oceanological station.

Theme "Vertical structural zones of the waters of the World Ocean".

Task 1. Construct vertical temperature and salinity distribution graphs for various types of stratification based on the data provided by the teacher (by options).

Task 2. Analyze the geographical types of temperature and salinity distribution by depth in the World Ocean (by options: tropical - temperate latitudes, subtropical - subpolar, equatorial - subtropical, tropical - polar).

Theme "Unrest in the oceans".

Task 1. Draw a diagram "Change of the profile of a trochoidal wave with depth" and prepare its analysis in text form.

Task 2. Independently, having worked through literary sources, prepare and fill out the table "Main characteristics of translational and standing waves with depth"

Theme "Influence of the ocean on climate and weather-forming processes in the atmosphere."

Task 1. Prepare in text form a comparative analysis of the map data "Heat received or lost by the ocean surface due to the action of sea currents" (according to the options: Atlantic - Pacific, Pacific - Indian, Atlantic - Indian, Arctic - Indian).

Task 2. Prepare and defend an essay on one of the following topics:

1) "Small-scale interaction of the ocean and the atmosphere",

2) "Mesoscale interaction of the ocean and atmosphere",

3) "Large-scale interaction of the ocean and the atmosphere",

4) "The El Niño-Southern Oscillation" system as a manifestation of the interannual variability of the "ocean-atmosphere" system,

5) "Response of the "ocean-atmosphere" system to changes in the albedo of the land surface",

6) "The response of the "ocean-atmosphere" system to a change in the concentration of atmospheric CO 2",

7) "The response of the "ocean-atmosphere" system to a change in the ratio of ocean and land areas",

8) "The response of the "ocean-atmosphere" system to changes in vegetation cover",

9) "Heat transfer in the "ocean-atmosphere" system",

10) “Moisture exchange in the “ocean-atmosphere” system”.

PROTOCOL OF APPROVAL OF THE HEI CURRICULUM

ADDITIONS AND CHANGES TO THE HEI CURRICULUM

for _____/_____ academic year

... disciplines « Physical continent geography and oceans» student must: Know: the state and prospects for the development of science, its role in modern scientific knowledge ...

The properties and dynamics of ocean waters, the exchange of energy and substances both in the World Ocean and between the oceanosphere and atmosphere are strongly dependent on the processes that determine the nature of our entire planet. At the same time, the World Ocean itself has an exceptionally strong influence on planetary processes, that is, on those processes with which the formation and change in the nature of the entire globe is associated.

The main oceanic fronts almost coincide in position with the atmospheric fronts. The significance of the main fronts is that they delimit the warm and highly saline sphere of the World Ocean from the cold and low saline one. Through the main fronts inside the ocean column, an exchange of properties occurs between low and high latitudes, and the final phase of this exchange is completed. In addition to hydrological fronts, climatic fronts of the ocean are distinguished, which is especially important, since the climatic fronts of the ocean, having a planetary scale, emphasize the general picture of the zonality of the distribution of oceanological characteristics and the structure of the dynamic system of water circulation on the surface of the World Ocean. They also serve as the basis for climatic zoning. At present, within the oceanosphere, there is a fairly large variety of fronts and frontal zones. They can be considered as the boundaries of waters with different temperatures and salinities, currents, etc. The combination in space of water masses and the boundaries between them (fronts) forms a horizontal hydrological structure of the waters of individual regions and the Ocean as a whole. In accordance with the law of geographical zonality, the following most important types in the horizontal structure of waters are distinguished: equatorial, tropical, subtropical, subarctic (subpolar) and subantarctic, arctic (polar) and antarctic. Each horizontal structural zone has, respectively, its own vertical structure, for example, the equatorial surface structural zone, the equatorial intermediate, the equatorial deep, the equatorial near-bottom and vice versa, horizontal structural zones can be distinguished in each vertical structural layer. In addition, within each horizontal structure, more fractional subdivisions are distinguished, for example, the Peru-Chilean or Californian structure, etc., which, ultimately, determines the diversity of the waters of the World Ocean. The boundaries of the separation of vertical structural zones are the boundary layers, and the most important types of waters of the horizontal structure are ocean fronts.

· Vertical structure of ocean waters

In each structure, water masses of the same name in terms of vertical arrangement in different geographical regions have different properties. Naturally, near the Aleutian Islands, or off the coast of Antarctica, or at the equator, the water column differs in all its physical, chemical and biological characteristics. However, water masses of the same type are connected by the commonality of their origin, close conditions of transformation and distribution, seasonal and long-term variability.

Surface water masses are most susceptible to the hydrothermodynamic influence of the entire complex of atmospheric conditions, in particular the annual variation in air temperature, precipitation, winds, and humidity. When transported by currents from areas of formation to other areas, surface waters are relatively quickly transformed and acquire new qualities.

Intermediate waters are formed mainly in the zones of climatically stationary hydrological fronts or in the Mediterranean-type seas of the subtropical and tropical belts. In the first case, they are formed as fresh and relatively cold, and in the second - as warm and salty. Sometimes an additional structural association is distinguished - subsurface intermediate waters located at a relatively shallow depth below the surface. They form in areas of intense evaporation from the surface (salty waters) or in areas of strong winter cooling in the subarctic and arctic regions of the oceans (cold intermediate layer).

The main feature of intermediate waters compared to surface waters is their almost complete independence from atmospheric influence along the entire path of distribution, although their properties in the source of formation differ in winter and summer. They are apparently formed by convection on the surface and in subsurface layers, as well as due to dynamic subsidence in the zones of fronts and convergence of currents. Intermediate waters spread mainly along isopycnal surfaces. Tongues of high or low salinity, found on the meridional sections, cross the main zonal jets of oceanic circulation. The advancement of the cores of the intermediate waters in the direction of languages ​​has not yet been satisfactorily explained. It is possible that it is carried out by lateral (horizontal) mixing. In any case, the geostrophic circulation in the core of intermediate waters repeats the main features of the subtropical circulation cycle and does not differ in extreme meridional components.

Deep and near-bottom water masses are formed at the lower boundary of intermediate waters by mixing and transforming them. But the main sources of origin of these waters are considered to be the shelf and continental slope of Antarctica, as well as the arctic and subpolar regions of the Atlantic Ocean. Thus, they are associated with thermal convection in the polar zones. Since the processes of convection have a pronounced annual course, the intensity of formation and the cyclicity in time and space of the properties of these waters must have seasonal variability. But these processes are almost not studied.

The aforementioned commonality of the water masses that make up the vertical structure of the ocean gave grounds to introduce a generalized concept of structural zones. The exchange of properties and mixing of waters in the horizontal direction occur at the boundaries of the main macroscale elements of water circulation, along which hydrological fronts pass. Thus, water areas of water masses are directly connected with the main water cycles.

Based on the analysis of a large number of averaged T, S-curves throughout the Pacific Ocean, 9 types of structures were identified (from north to south): subarctic, subtropical, tropical and east-tropical northern, equatorial, tropical and subtropical southern, subantarctic, antarctic. The northern subarctic and both subtropical structures have eastern varieties, due to the specific regime of the eastern part of the ocean off the coast of America. The northern east-tropical structure also gravitates towards the coasts of California and southern Mexico. The boundaries between the main types of structures are elongated in the latitudinal direction, with the exception of the eastern varieties, in which the western boundaries have a meridional orientation.

The boundaries between the types of structures in the northern part of the ocean are consistent with the boundaries of the types of stratification of vertical temperature and salinity profiles, although the source materials and the method of obtaining them are different. Moreover, a set of types of vertical T- and S-profiles determine the structures and their boundaries in much more detail.

The subarctic structure of waters has a vertically monotonous increase in salinity and a more complex change in temperature. At depths of 100 - 200 m in the cold subsurface layer, the largest salinity gradients along the entire vertical are observed. A warm intermediate layer (200 - 1000 m) is observed when the salinity gradients are weakened. The surface layer (up to 50 - 75 m) is subject to sharp seasonal changes in both properties.

Between 40 and 45° N. sh. there is a transitional zone between the subarctic and subtropical structures. Moving eastward from 165° - 160° W. etc., it passes directly into the eastern varieties of the subarctic, subtropical and tropical structures. On the surface of the ocean, at depths of 200 m and partly at 800 m throughout this zone, there are waters similar in properties, which belong to the subtropical water mass.

The subtropical structure is divided into layers, in which there are corresponding water masses of different salinity. The subsurface layer of increased salinity (60 - 300 m) is characterized by increased vertical temperature gradients. This leads to the preservation of a stable vertical stratification of waters by density. Below 1000 - 1200 m are deep, and deeper than 3000 m - bottom waters.

Tropical waters have significantly higher surface temperatures. The subsurface layer of increased salinity is thinner but has higher salinity.

In the intermediate layer, reduced salinity is not pronounced sharply due to the distance from the source of formation on the subarctic front.

The equatorial structure is characterized by a surface freshened layer (up to 50 - 100 m) with a high temperature in the west and a significant decrease in it in the east. Salinity also decreases in the same direction, forming an eastern equatorial-tropical water mass off the coast of Central America. The subsurface layer of increased salinity occupies an average thickness of 50 to 125 m, and in terms of salinity it is slightly lower than in the tropical structures of both hemispheres. Intermediate water here is of southern, subantarctic origin. On a long journey, it is intensively washed out, and its salinity is relatively high - 34.5 - 34.6%o. In the north of the equatorial structure, two layers of low salinity are observed.

The structure of the waters of the southern hemisphere has four types. Immediately adjacent to the equator is a tropical structure that extends southward to 30°S. sh. in the west and up to 20 ° S. sh. in the east of the ocean. It has the highest salinity on the surface and in the subsurface layer (up to 36.5°/oo), as well as the maximum temperature for the southern part. The subsurface layer of high salinity extends to a depth of 50 to 300 m. Particularly low salinity is noted in the east of the tropical structure. Deep and bottom waters have a temperature of 1 - 2°C and a salinity of 34.6 - 34.7°/oo.

The southern subtropical structure differs from the northern one in greater salinity at all depths. This structure also has a subsurface saline layer, but it often comes to the surface of the ocean. Thus, a particularly deep, sometimes up to 300 - 350 m, superficial, almost uniform layer of increased salinity is formed - up to 35.6 - 35.7 ° / oo. Intermediate water of low salinity is located at the greatest depth (up to 1600 - 1800 m) with a salinity of up to 34.2 - 34.3% o.

In the subantarctic structure, the salinity on the surface decreases to 34.1 - 34.2%o, and the temperature - to 10 - 11°C. In the core of the layer of increased salinity, it is 34.3 - 34.7%o at depths of 100 - 200 m, in the core of intermediate water of low salinity, it decreases to 34.3%o, and in deep and bottom waters it is the same as in in general for the Pacific Ocean - 34.6 - 34.7 ° / oo.

In the Antarctic structure, salinity increases monotonously towards the bottom from 33.8 - 33.9%o to maximum values ​​in the deep and near-bottom waters of the Pacific Ocean: 34.7 - 34.8°/oo. In the temperature stratification, the cold subsurface and warm intermediate layers reappear. The first of them is located at depths of 125 - 350 m with a temperature of up to 1.5 ° in summer, and the second - from 350 to 1200 - 1300 m with a temperature of up to 2.5 °. Deep waters here have the highest lower limit - up to 2300 m.

(about 70%), consisting of a number of individual components. Any analysis of the structure of M.o. associated with the component partial structures of the ocean.

Hydrological structure of MO.

temperature stratification. In 1928, Defant formulated a theoretical position on the horizontal division of the MO into two water layers. The upper part is the oceanic troposphere, or "Warm Ocean" and the oceanic stratosphere, or "Cold Ocean". The boundary between them runs obliquely, varying from an almost vertical to a horizontal position. At the equator, the boundary is at a depth of about 1 km; in polar latitudes, it can run almost vertically. The waters of the "warm" ocean are lighter than the polar waters and are located on them as on a liquid bottom. Despite the fact that the warm ocean is present almost everywhere and, therefore, the boundary between it and the cold ocean is of considerable length, water exchange between them occurs only in very few places, due to the rise of deep waters (upwelling), or the sinking of warm waters (downwelling) .

Geophysical structure of the ocean(presence of physical fields). One of the factors of its presence is the thermodynamic exchange between the ocean and the atmosphere. According to Shuleikin (1963), the ocean should be considered as a heat engine operating in the meridional direction. The equator is a heater, and the poles are refrigerators. Due to the circulation of the atmosphere and ocean currents, there is a constant outflow of heat from the equator to the poles. The equator divides the oceans into 2 parts with partially isolated systems of currents, and the continents divide the M.o. to the regions. Thus, oceanography subdivides the MO into 7 parts: 1) the Arctic, 2) the Northern part of the Atlantic, 3) the northern part of the Indian, 4) the northern part of the Pacific, 5) the southern part of the Atlantic, 6) the southern part of the Pacific, 7) the southern part of the Indian.

In the ocean, as elsewhere in the geographic envelope, there are bordering surfaces (ocean/atmosphere, coast/ocean, bottom/water mass, cold/warm WM, more saline/less saline WM, etc.). It has been established that the greatest activity of chemical processes occurs precisely on the boundary surfaces (Aizatulin, 1966). Around each such surface there is an increased field of chemical activity and physical anomalies. MO is divided into active layers, the thickness of which, when approaching the boundary that generates them, decreases down to molecular, and the chemical activity and the amount of free energy increase to the maximum. If several borders are crossed, then all processes are even more active. The maximum activity is observed on the coasts, on the ice edge, on oceanic fronts (VMs of different origin and characteristics).

Most active:

1. the equatorial zone, where the VMs of the northern and southern parts of the oceans contact, swirling in opposite directions (clockwise or counterclockwise).
2. contact zones of oceanic waters from different depths. In upwelling areas, stratosphere waters rise to the surface, in which a large amount of mineral substances are dissolved, which are food for plants. In areas of downwellin, oxygen-rich surface water sinks to the ocean floor. In such areas, biomass increases by 2 times.
3. areas of hydrotherms (submarine volcanoes). Here, chemosynthesis-based "ecological oases" are formed. In them, organisms exist at temperatures up to +400ºС and salinity up to 300 ‰. Archaeobacteria were found here, dying at +100ºС from hypothermia and related to those that existed on Earth 3.8 billion years ago, bristleworms living in solutions resembling sulfuric acid at a temperature of +260ºС.
4. river mouths.
5. straits.
6. underwater rapids

The least active are the central parts of the oceans, which are farthest from the bottom and coasts.

biological structure.

Until the mid 60s. It was believed that the ocean could feed mankind. But it turned out that only about 2% of the ocean's water masses are saturated with life. There are several approaches to characterizing the biological structure of the ocean.

1. The approach is associated with the identification of accumulations of life in the ocean. Here, 4 static accumulations of life are distinguished: 2 films of life, surface and near-bottom, approximately 100 m thick, and 2 concentrations of life: coastal and Sargasso - accumulation of organisms in the open ocean, where the bottom plays no role, associated with the rise and fall of water in the ocean, frontal zones in the ocean

2. Zenkevich's approach is associated with the identification of symmetry in the ocean exists. Here there are 3 planes of symmetry in the phenomena of the biotic environment: equatorial, 2 meridional passing respectively in the center of the ocean and in the center of the mainland. In relation to them, there is a change in biomass from the coast to the center of the ocean, the biomass decreases. Latitudinal belts in the ocean are distinguished in relation to the equator.

   1. the equatorial zone with a length of about 10 0 (from 5 0 N to 5 0 S) is a band rich in life. A lot of species with a small number of each. Fishing is usually not very profitable.
   2. subtropical-tropical zones (2) - zones of oceanic deserts. There are quite a lot of species, phytoplankton is active year-round, but bioproductivity is very low. The maximum number of organisms lives on coral reefs and in mangroves (coastal semi-flooded plant formations).
   3. zones of temperate latitudes (2 zones) have the highest bioproductivity. Species diversity in comparison with the equator decreases sharply, but the number of individuals of one species increases sharply. These are areas of active fishing. 4) polar zones - areas with minimal biomass due to the fact that phytoplankton photosynthesis stops in winter.

3. Ecological classification. Allocate ecological groups of living organisms.

   1. plankton (from the Greek Planktos - wandering), a set of organisms that live in the water column and are unable to resist the transfer by the current. Consists of bacteria, diatoms and some other algae (phytoplankton), protozoa, some coelenterates, mollusks, crustaceans, fish eggs and larvae, invertebrate larvae (zooplankton).
   2. nekton (from the Greek nektos - floating), a set of actively swimming animals that live in the water column, able to resist the current and move over considerable distances. Nekton includes squid, fish, sea snakes and turtles, penguins, whales, pinnipeds, etc.
   3. benthos (from the Greek. benthos - depth), a set of organisms that live on the ground and in the soil of the bottom of reservoirs. Some of them move along the bottom: starfish, crabs, sea urchins. Others attach to the bottom - corals, scallops, algae. Some fish swim near the bottom or lie on the bottom (stingrays, flounder), can dig into the ground.
   4. Other, smaller ecological groups of organisms are also distinguished: pleuston - organisms floating on the surface; neuston - organisms that attach to the water film from above or below; hyponeuston - live directly under the film of water.

1. Unity MO
2. Within the MO structure, circular structures are distinguished.
3. The ocean is anisotropic, i.e. transmits the influence of adjacent surfaces at different speeds in different directions. A drop of water from the surface of the Atlantic Ocean to the bottom moves 1000 years, and from east to west from 50 days to 100 years.
4. The ocean has vertical and horizontal zonality, which leads to the formation of internal boundaries of a lower rank within the ocean.
5. The significant dimensions of the MO shift the lower boundary of the GO in it to 11 km depth.

1. low accessibility for humans;
2. difficulties in developing technology for studying the ocean;
3. a short period of time in which the ocean is studied.

The structure of the World Ocean is its structure - vertical stratification of waters, horizontal (geographical) zonality, the nature of water masses and ocean fronts.

Vertical stratification of the oceans

In a vertical section, the water column breaks up into large layers, similar to the layers of the atmosphere. They are also called spheres. The following four spheres (layers) are distinguished:

The upper sphere is formed by direct exchange of energy and matter with the troposphere in the form of microcirculation systems. It covers a layer of 200-300 m thick. This upper sphere is characterized by intense mixing, light penetration and significant temperature fluctuations.

The upper sphere breaks up into the following partial layers:

• a) the uppermost layer is several tens of centimeters thick;
• b) wind effect layer with a depth of 10-40 cm; he participates in excitement, reacts to the weather;
• c) a layer of temperature jump, in which it drops sharply from the upper heated layer to the lower layer, not affected by waves and not heated;
• d) penetration layer of seasonal circulation and temperature variability.

Ocean currents usually capture water masses only in the upper sphere.

The intermediate sphere extends to depths of 1500 - 2000 m; its waters are formed from surface waters when they sink. At the same time, they are cooled and compacted, and then mixed in horizontal directions, mainly with a zonal component. Horizontal transfers of water masses predominate.

The deep sphere does not reach the bottom by about 1,000 m. A certain uniformity is characteristic of this sphere. ITS thickness is about 2,000 m and it concentrates more than 50% of all water in the oceans.

The bottom sphere occupies the lowest layer of the ocean and extends to a distance of about 1,000 m from the bottom. The waters of this sphere are formed in cold zones, in the Arctic and Antarctic, and move over vast expanses along deep basins and trenches. They perceive heat from the bowels of the Earth and interact with the ocean floor. Therefore, during their movement, they are significantly transformed.

9.10 Water masses and ocean fronts in the upper ocean

A water mass is a relatively large volume of water that forms in a certain area of ​​the World Ocean and has almost constant physical (temperature, light), chemical (gases) and biological (plankton) properties for a long time. The water mass moves as a whole. One mass is separated from another by an ocean front.

The following types of water masses are distinguished:

• 1. Equatorial water masses are limited by equatorial and subequatorial fronts. They are characterized by the highest temperature in the open ocean, low salinity (up to 34-32‰), minimum density, high content of oxygen and phosphates.
• 2. Tropical and subtropical water masses are created in areas of tropical atmospheric anticyclones and are limited from the side of temperate zones by tropical northern and tropical southern fronts, and subtropical - by northern temperate and northern southern fronts. They are characterized by high salinity (up to 37‰ and more) and high transparency, lack of nutrient salts and plankton. Ecologically, tropical water masses are oceanic deserts.
• 3. Moderate water masses are located in temperate latitudes and are limited from the side of the poles by the Arctic and Antarctic fronts. They are characterized by great variability of properties both in geographical latitudes and in seasons. Moderate water masses are characterized by an intense exchange of heat and moisture with the atmosphere.
• 4. The polar water masses of the Arctic and Antarctic are characterized by the lowest temperature, highest density, and high oxygen content. The waters of the Antarctic sink intensively into the near-bottom sphere and supply it with oxygen.

Causes that upset the balance: Currents Ebb and flow Changes in atmospheric pressure Wind Coastline Water runoff from land

The world ocean is a system of communicating vessels. But their level is not always and everywhere the same: at one latitude higher near the western coast; on one meridian rises from south to north

Circulation systems Horizontal and vertical transfer of masses of water is carried out in the form of a system of vortices. Cyclonic eddies - a body of water moves counterclockwise and rises. Anticyclonic eddies - the mass of water moves clockwise and sinks. Both motions are generated by frontal perturbations of the atmo-hydrosphere.

Convergence and Divergence Convergence is the convergence of water masses. The ocean level is rising. The pressure and density of water rises and it falls. Divergence is the divergence of water masses. The ocean level is dropping. Deep water rises. http://www. youtube. com/watch? v=dce. MYk. G 2 j. kw

Vertical stratification Upper sphere (200 -300 m.) A) upper layer (several micrometers) B) wind effect layer (10 -40 m.) C) temperature jump layer (50 -100 m.) D) seasonal circulation penetration layer and temperature variability Ocean currents capture only the water masses of the upper sphere.

Deep sphere Does not reach the bottom at 1000 m.