Changes in the temperature of the world's oceans. Temperature level of seas and oceans
The ocean receives a lot of heat from the Sun. Occupying large area, it receives more heat than land.
But the sun's rays heat only the top layer of water, only a few meters thick. Heat is transferred down from this layer as a result of constant mixing of water. But it should be noted that the water temperature decreases with depth, first abruptly, and then smoothly. At depth, the water is almost uniform in temperature, since the depths of the oceans are mainly filled with waters of the same origin, formed in polar regions Earth. At a depth of more than 3-4 thousand meters, the temperature usually ranges from +2°C to 0°C.
Temperature surface waters also unequal and distributed depending on geographic latitude. The farther from the equator, the lower the temperature. It's connected with varying amounts heat that comes from the Sun. Due to the spherical shape of our planet, the angle of incidence sunbeam at the equator more than at the poles, therefore equatorial latitudes receive more heat than polar latitudes. The highest ocean water temperatures are observed at the equator - +28-29°C. To the north and south of it, the water temperature decreases. Due to the proximity of cold Antarctica, the rate of temperature decrease in the south is slightly faster than in the north.
For temperature sea water The climate of the surrounding areas also influences. It is especially high in seas surrounded by hot deserts, for example in the Red Sea - up to 34°C, in Persian Gulf- up to 35.6°C. IN temperate latitudes The temperature varies depending on the time of day.
The tallest average temperature at the surface of the water in the Pacific Ocean is 19.4°C. Second place (17.3°C) is occupied by the Indian Ocean. In third place is the Atlantic Ocean, which has an average temperature of about 16.5°C. Most low temperature water in the Arctic Ocean averages just above 1°C. Consequently, for the entire World Ocean, the average temperature of surface waters is about 17.5°C.
So, the ocean absorbs 25-50% more heat than land, and this is its huge role for living beings on the entire planet. The sun heats its water all summer, and in winter this heated water gradually releases heat to the atmosphere. Thus, the World Ocean is something like a “boiler central heating» Earth. Without it, such severe frosts will come on Earth that all living things will die. It has been calculated that if the oceans did not conserve their heat so carefully, the average temperature on Earth would be -21°C, which is as much as 36°C lower than what we actually have.
I think I can give a sufficient answer, because at school I prepared a report on this topic. There was no Internet back then, which meant that preparation took longer, and maybe that’s why I remembered so many things. About, Why does the temperature of the world's oceans change?, and most importantly, I will try to tell you how this happens.
Temperature of the World Ocean
In fact, the ocean receives a lot more heat than land, and the point is not even in its huge area, but in the fact that water is characterized by excellent heat capacity. In other words, water is much better holds the received thermal energy than, for example, rocks and ordinary soil. The sun's rays heat only the upper layers, and this causes a phenomenon such as water circulation, however, this process does not affect the lowest layers and a relatively stable temperature is observed there - 0-2°C.
What determines the temperature of the oceans?
Science identifies several global factors that they provide significant influence. So this is:
- geographic latitude - in fact, the main determining factor;
- climate- its features in nearby areas significantly affect the water temperature;
- currents- thanks to this phenomenon, a smooth distribution of heat occurs.
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As you move away from the equator, there is a decrease in temperature, due to the fact that equatorial regions significantly more thermal energy is required. Average near the equator it varies within +30°С, and as you move away gradually decreases towards the poles. At the same time, in Southern Hemisphere observed high speed lower temperatures due to the proximity of Antarctica.
The temperature of the seas that are surrounded by deserts is extremely depends on climate In these areas, for example, the Red Sea is characterized by temperatures up to 36°C. At the same time, depending on the time of day, the water temperature in temperate latitudes changes. As for currents, they are characterized by transport of cold masses from polar regions and the movement of warm temperatures to temperate latitudes.
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In view of the fact that ocean waters absorb hugeThe amount of heat, its role in maintaining life can hardly be overestimated. All the heat that was “accumulated” over the summer gradually enters the atmosphere during winter, where it is distributed throughout the planet. According to calculations, if the ocean did not have such a remarkable property, the average temperature of the planet would be -23°C, and this is by no means best condition for life!
Water temperature and salinity
The temperature of the waters of the World Ocean is not the same in different places. The oceans warm up more in stripes of about 20°N. w. And
20°pl. sh., which coincide with the regions high pressure This is explained by low cloudiness in subtropical, tropical and subequatorial latitudes. Oceans absorb heat mainly in the 30°N zone. w. - 20°S latitude, and give it to the atmosphere at higher latitudes. This - important factor climate mitigation in temperate and polar latitudes during the cold season.
Only the top 1 cm thick layer of water collects solar heat. It absorbs 94% of solar energy that hits the ocean surface. From the surface solar energy transmitted deep. The main role is played by dynamic processes due to various reasons. All together dynamic processes (vertical and horizontal movements water) cause good movement of heat from the surface to different depths. Thanks to this, the waters of the oceans are profitable in their entire thickness and concentrate a huge amount of heat.
The average water temperature on the surface of the World Ocean is +17.54 ° C (air temperature above the ocean is +14.4 ° C). The average surface water temperature in the northern and southern polar regions is 0.75 and -0.79 ° C, respectively, in the equatorial zone +26.7 ° C and +27.3 ° C. In the Northern Hemisphere, the water temperature is higher than in Southern, which is explained by the influence of continents.
On great depths temperature distribution is determined by deep circulation. Waters sank at high latitudes have a lower temperature than those sank at low latitudes. In the bottom layer, the temperature varies from 1.4 1.8 ° C in low latitudes to 0 ° C and lower in high latitudes.
The salinity of ocean water is one of its most important features.
Water is the best solvent. Although it is weak (retains about 4% by weight of dissolved solid), but very rich in quality composition solution. All known elements are dissolved in water, although mostly in minute quantities, but in total they add up to significant values. Suffice it to say that, in addition to huge amount main salts - NaCl, MgSO, MgCl 2, approximately 8 million tons of gold, 80 million tons of nickel, 164 million tons of silver, 800 million tons of molybdenum, 80 billion tons of iodine, and the like are dissolved in sea water.
In addition to solid matter, gases (oxygen, nitrogen, carbon dioxide, and in stagnant waters - hydrogen sulfide) and organic matter are also dissolved in water.
The salinity of sea water determines its freezing temperature and maximum density, and the duration of water mixing processes in the oceans depends on them. Consequently, it affects the air temperature and the Earth's climate.
Salinity in the World Ocean is distributed unevenly and depends mainly on the ratio of evaporation and precipitation. In polar and subpolar regions, where water is desalinated by melting ice, salinity is lower: in the Arctic it averages 31.4 ‰. in Antarctica - 33.93% o.
In temperate latitudes, salinity is close to normal (average) and is approximately 35 ‰. This is explained by intense mixing of water in these latitudes. The highest salinity in the open ocean is in the sub tropical latitudes both hemispheres (where evaporation predominates over precipitation) - more than 37.25 ‰. In the equatorial zone, due to desalination by precipitation, it is slightly below average. The highest salinity of the World Ocean is in closed seas tropical zone- more than 42 ‰ (Red Sea). Salinity changes very little with depth.
Movement of water in the World Ocean. Sea currents
Sea currents - gradual movements water masses in the oceans and seas, due to by various forces(gravity, friction and tide-damping). They play a significant role in the life of the World Ocean and navigation; contribute to the exchange of water masses, changes in coastlines (destruction, alluvium of new land), shallowing of port water areas, ice transfer, etc.; big influence on climate different parts globe; for example, North Atlantic Current systems moderate the climate of Europe. Sea currents differ: by origin - sea currents caused by the friction of the wind on the sea surface (wind currents), uneven distribution of temperature and salinity of water (current density), level slope (discharge currents), etc.; according to the level of stability - stable, changeable, temporary, periodic (for example, seasonal currents, which change directions under the influence of monsoons) by location - surface, subsurface, intermediate, deep, bottom; By physical and chemical properties- warm, cold, desalinated, salted.
The direction of sea currents is influenced by the rotation of the Earth, which deflects currents in the Northern Hemisphere to the right, and in the Southern Hemisphere to the left.
The main surface currents arise under the influence of the trade winds that blow over the oceans throughout the year.
Consider the currents of the Pacific Ocean. The current, arising under the influence of the northeastern trade wind, forms an angle of 45 ° with it, deviating to the right due to the prevailing wind direction. Therefore, the current flows from east to west along the equator, slightly north of it. This current creates the northeast trade wind. It is called the Northern Trade Wind.
The southeast trade wind forms the South Trade Wind Current, which deviates from the direction of the trade wind to the left by 45°. It has the same direction as the previous one, from east to west, but passes south of the equator.
Both trade wind (equatorial) currents, running parallel to the equator, reach the eastern coast of the continents and branch, with one jet returning along the coast to the north, and the second to the south. The southern branch of the Northern Trade Wind Current and the northern branch of the Southern Trade Wind Current are moving towards each other. Having met, they merge and flow through the equatorial calm zone, moving from west to east, forming an equatorial countercurrent.
The right branch of the Northern Trade Wind Current goes north along the eastern coast of the mainland. Due to the rotation of the Earth, it gradually deviates from the coast and at the 40th parallel turns east into the open ocean. Here they pick him up southwesterly winds and forced to walk in a direction from west to east. Having reached the western coast of the continent, the current branches, its right branch goes to the south, deviated by the rotation of the Earth to the right, and therefore moves away from the coast. Having reached the Northern Trade Wind (Equatorial) Current, this branch merges with it and forms a closed northern equatorial ring of currents.
The left branch of the current heads north, is deflected by the rotation of the Earth to the right, presses against the western coast of the continent and runs along it.
Northeast winds blowing from the polar region also create a current. She is carrying very cold water, goes south along east coast continent of Eurasia.
In the Southern Hemisphere, the left branch of the South Trade Wind Current heads south along the eastern coast of Australia, and is deflected to the left by the Earth's rotation and pushed away from the coast. At the 40th parallel, this branch of the current returns to the open ocean, is picked up by northwest winds and goes from west to east. U western shores America's currents are branching. The left branch returns along the coast of the mainland to the north. Deflected by the rotation of the Earth to the left, this current departs from the coast and connects with the South Trade Wind Current, forming the southern equatorial ring of currents. The right branch, past the southern tip of America, runs east into the neighboring ocean.
Waves arising from earthquakes and volcanic eruptions when the waters fall onto the shore. Waves of this origin are called tsunamis.
As a result of the action of the Moon on the surface of the World Ocean, tides arise. Very high tides occur in the Gulf of Saint-Malo in France - up to 15 m. At the top of the Gulf of File, the tide height can reach 18 m.
In the southern part of the Atlantic Ocean, high tides - up to 12-14 m - can be observed off the coast of Patagonia, north of the entrance to the Strait of Magellan.
In the Pacific Ocean, the highest tides are in the Sea of Okhotsk off the coast of Russia.
IN Indian Ocean high tides occur off the western coast of India (up to 12 m).
Water is the simplest chemical compound of hydrogen and oxygen, but ocean water is a universal, homogeneous ionized solution, which contains 75 chemical elements. These are solid minerals(salts), gases, as well as suspensions of organic and inorganic origin.
Vola has many different physical and chemical properties. First of all, they depend on the table of contents and temperature environment. Let's give brief description some of them.
Water is a solvent. Since water is a solvent, we can judge that all waters are gas-salt solutions of various chemical composition and different concentrations.
Salinity of ocean, sea and river water
Salinity of sea water(Table 1). The concentration of substances dissolved in water is characterized by salinity, which is measured in ppm (%o), i.e. grams of a substance per 1 kg of water.
Table 1. Salt content in sea and river water (in% of the total mass of salts)
Basic connections |
Sea water |
river water |
Chlorides (NaCI, MgCb) |
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Sulfates (MgS0 4, CaS0 4, K 2 S0 4) |
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Carbonates (CaSOd) |
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Compounds of nitrogen, phosphorus, silicon, organic and other substances |
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Lines on a map connecting points with the same salinity are called isohalines.
Salinity fresh water (see Table 1) is on average 0.146%o, and sea - on average 35 %O. Salts dissolved in water give it a bitter-salty taste.
About 27 of the 35 grams is sodium chloride (table salt), so the water is salty. Magnesium salts give it a bitter taste.
Since the water in the oceans was formed from hot salty solutions of the earth's interior and gases, its salinity was original. There is reason to believe that in the first stages of the formation of the ocean, its waters differed little in salt composition from river waters. Differences emerged and began to intensify after the transformation rocks as a result of their weathering, as well as the development of the biosphere. The modern salt composition of the ocean, as shown by fossil remains, developed no later than the Proterozoic.
In addition to chlorides, sulfites and carbonates, almost all chemical elements known on Earth, including noble metals, were found in sea water. However, the content of most elements in sea water is negligible; for example, only 0.008 mg of gold per cubic meter of water was detected, and the presence of tin and cobalt is indicated by their presence in the blood of marine animals and in bottom sediments.
Salinity of ocean waters— the value is not constant (Fig. 1). It depends on climate (the ratio of precipitation and evaporation from the ocean surface), the formation or melting of ice, sea currents, and near continents - on the influx of fresh water. river waters.
Rice. 1. Dependence of water salinity on latitude
In the open ocean, salinity ranges from 32-38%; in the outskirts and Mediterranean seas its fluctuations are much greater.
The salinity of waters down to a depth of 200 m is especially strongly influenced by the amount of precipitation and evaporation. Based on this, we can say that the salinity of sea water is subject to the law of zonation.
In equatorial and subequatorial regions, salinity is 34%c, because the amount of precipitation more water, spent on evaporation. In tropical and subtropical latitudes- 37 since there is little precipitation and evaporation is high. In temperate latitudes - 35%o. The lowest salinity of sea water is observed in the subpolar and polar regions - only 32, since the amount of precipitation exceeds evaporation.
Sea currents, river runoff and icebergs disrupt the zonal pattern of salinity. For example, in temperate latitudes Northern Hemisphere The salinity of the waters is greater near the western shores of the continents, where saltier subtropical waters are brought with the help of currents; the water salinity is lower near eastern shores, where cold currents bring less salty water.
Seasonal changes in water salinity occur in subpolar latitudes: in the fall, due to the formation of ice and a decrease in the strength of river flow, the salinity increases, and in the spring and summer, due to the melting of ice and an increase in river flow, the salinity decreases. Around Greenland and Antarctica in summer period salinity becomes less as a result of the melting of nearby icebergs and glaciers.
The saltiest of all oceans is Atlantic Ocean, the waters of the Arctic Ocean have the lowest salinity (especially off the Asian coast, near the mouths Siberian rivers- less than 10%o).
Among parts of the ocean - seas and bays - the maximum salinity is observed in areas limited by deserts, for example, in the Red Sea - 42%c, in the Persian Gulf - 39%c.
The salinity of water determines its density, electrical conductivity, ice formation and many other properties.
Gas composition of ocean water
In addition to various salts, various gases are dissolved in the waters of the World Ocean: nitrogen, oxygen, carbon dioxide, hydrogen sulfide, etc. As in the atmosphere, oxygen and nitrogen predominate in ocean waters, but in slightly different proportions (for example, total free oxygen in the ocean is 7480 billion tons, which is 158 times less than in the atmosphere). Despite the fact that gases occupy relatively little space in water, this is enough to influence organic life and various biological processes.
The amount of gases is determined by the temperature and salinity of the water: the higher the temperature and salinity, the lower the solubility of gases and the lower their content in water.
So, for example, at 25 °C up to 4.9 cm/l of oxygen and 9.1 cm3/l of nitrogen can dissolve in water, at 5 °C - 7.1 and 12.7 cm3/l, respectively. Two important consequences follow from this: 1) the oxygen content in the surface waters of the ocean is much higher in temperate and especially polar latitudes than in low (subtropical and tropical) latitudes, which affects the development organic life— the wealth of the first and relative poverty of the second waters; 2) at the same latitudes, the oxygen content in ocean waters is higher in winter than in summer.
Daily changes gas composition waters associated with temperature fluctuations are small.
The presence of oxygen in ocean water promotes the development of organic life in it and the oxidation of organic and mineral products. The main source of oxygen in ocean water is phytoplankton, called lungs of the planet" Oxygen is mainly consumed for the respiration of plants and animals in the upper layers of sea waters and for oxidation various substances. In the depth range of 600-2000 m there is a layer oxygen minimum. A small amount of oxygen is combined here with a high content carbon dioxide. The reason is the decomposition in this layer of water of the bulk of the organic matter coming from above and the intensive dissolution of biogenic carbonate. Both processes require free oxygen.
The amount of nitrogen in seawater is much less than in the atmosphere. This gas mainly enters water from the air during decay organic matter, but is also produced during the respiration of marine organisms and their decomposition.
In the water column, in deep stagnant basins, as a result of the vital activity of organisms, hydrogen sulfide is formed, which is toxic and inhibits the biological productivity of waters.
Heat capacity of ocean waters
Water is one of the most heat-intensive bodies in nature. The heat capacity of just a ten meter layer of the ocean is four times greater than the heat capacity of the entire atmosphere, and a 1 cm layer of water absorbs 94% of the solar heat arriving at its surface (Fig. 2). Due to this circumstance, the ocean slowly warms up and slowly releases heat. Due to the high heat capacity, everything water bodies are powerful heat accumulators. As the water cools, it gradually releases its heat into the atmosphere. Therefore, the World Ocean performs the function thermostat of our planet.
Rice. 2. Dependence of heat capacity on temperature
Ice and especially snow have the lowest thermal conductivity. As a result, ice protects the water on the surface of the reservoir from hypothermia, and snow protects the soil and winter crops from freezing.
Heat of vaporization water - 597 cal/g, and heat of fusion - 79.4 cal/g - these properties are very important for living organisms.
Ocean temperature
An indicator of the thermal state of the ocean is temperature.
Average ocean temperature- 4 °C.
Despite the fact that the surface layer of the ocean acts as a thermostat for the Earth, in turn, the temperature of sea waters depends on heat balance(heat inflow and outflow). Heat inflow consists of , and heat consumption consists of the costs of water evaporation and turbulent heat exchange with the atmosphere. Despite the fact that the proportion of heat spent on turbulent heat exchange is not large, its significance is enormous. It is with its help that planetary heat redistribution occurs through the atmosphere.
At the surface, ocean temperatures range from -2°C (freezing point) to 29°C in the open ocean (35.6°C in the Persian Gulf). Average annual temperature surface waters of the World Ocean is 17.4°C, and in the Northern Hemisphere it is approximately 3°C higher than in the Southern Hemisphere. Highest temperature surface ocean waters in the Northern Hemisphere - in August, and the lowest - in February. In the Southern Hemisphere the opposite is true.
Since it has thermal relationships with the atmosphere, the temperature of surface waters, like the air temperature, depends on the latitude of the area, i.e., it is subject to the law of zonation (Table 2). Zoning is expressed in a gradual decrease in water temperature from the equator to the poles.
In tropical and temperate latitudes, water temperature mainly depends on sea currents. Thus, thanks to warm currents in tropical latitudes, temperatures in the western oceans are 5-7 °C higher than in the east. However, in the Northern Hemisphere, due to warm currents in the east of the oceans, temperatures are positive all year round, and in the west, due to cold currents, the water freezes in winter. In high latitudes, the temperature during the polar day is about O °C, and during polar night under the ice - about -1.5 (-1.7) °C. Here the water temperature is mainly affected by ice phenomena. In the fall, heat is released, softening the temperature of the air and water, and in the spring, heat is spent on melting.
Table 2. Average annual temperatures of ocean surface waters
Average annual temperature, "C |
Average annual temperature, °C |
||||
North hemisphere |
Southern Hemisphere |
North hemisphere |
Southern Hemisphere |
||
The coldest of all oceans- Northern Arctic, and the warmest — Pacific Ocean, since its main area is located in equatorial-tropical latitudes (average annual water surface temperature -19.1 °C).
An important influence on the temperature of ocean water is exerted by the climate of the surrounding areas, as well as the time of year, since solar heat, which heats the upper layer of the World Ocean, depends on this. The highest water temperature in the Northern Hemisphere is observed in August, the lowest in February, and vice versa in the Southern Hemisphere. Daily fluctuations in sea water temperature at all latitudes are about 1 °C, highest values annual temperature fluctuations are observed in subtropical latitudes - 8-10 °C.
The temperature of ocean water also changes with depth. It decreases and already at a depth of 1000 m almost everywhere (on average) below 5.0 °C. At a depth of 2000 m, the water temperature levels out, decreasing to 2.0-3.0 ° C, and in polar latitudes - to tenths of a degree above zero, after which it either decreases very slowly or even increases slightly. For example, in rift zones of the ocean, where at great depths there are powerful outlets of underground hot waters located under high pressure, with temperatures up to 250-300 °C. In general, there are two main layers of water vertically in the World Ocean: warm superficial And powerful cold, extending to the bottom. Between them there is a transition temperature jump layer, or main thermal clip, within it there is a sharp drop in temperature.
This picture of the vertical distribution of water temperature in the ocean is disrupted at high latitudes, where at a depth of 300-800 m a layer of warmer and saltier water coming from temperate latitudes can be traced (Table 3).
Table 3. Average ocean water temperatures, °C
Depth, m |
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Equatorial |
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Tropical |
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Polar |
Change in water volume with temperature change
A sharp increase in the volume of water when freezing- This is a peculiar property of water. At sharp decline temperature and its transition through zero mark is happening sharp increase volume of ice. As the volume increases, the ice becomes lighter and floats to the surface, becoming less dense. Ice protects deep layers of water from freezing, as it is a poor conductor of heat. The volume of ice increases by more than 10% compared to the initial volume of water. When heated, the opposite process of expansion occurs—compression.
Density of water
Temperature and salinity are the main factors determining the density of water.
For sea water, the lower the temperature and higher the salinity, the greater the density of the water (Fig. 3). Thus, at a salinity of 35%o and a temperature of 0 °C, the density of sea water is 1.02813 g/cm 3 (the mass of each cubic meter of such sea water is 28.13 kg more than the corresponding volume of distilled water). The temperature of sea water with the highest density is not +4 °C, like fresh water, but negative (-2.47 °C at a salinity of 30% and -3.52 °C at a salinity of 35%o
Rice. 3. Relationship between the density of sea ox and its salinity and temperature
Due to the increase in salinity, the density of water increases from the equator to the tropics, and as a result of a decrease in temperature, from temperate latitudes to the Arctic Circle. In winter, polar waters descend and move in the bottom layers towards the equator, therefore deep waters The world's oceans are generally cold, but enriched with oxygen.
The dependence of water density on pressure was revealed (Fig. 4).
Rice. 4. Dependence of seawater density (L"=35%o) on pressure at different temperatures
The ability of water to self-purify
This important property water. During the process of evaporation, water passes through the soil, which, in turn, is a natural filter. However, if the pollution limit is violated, the self-cleaning process is disrupted.
Color and transparency depend on reflection, absorption and scattering sunlight, as well as from the presence of suspended particles of organic and mineral origin. In the open part, the color of the ocean is blue; near the coast, where there is a lot of suspended matter, it is greenish, yellow, and brown.
In the open part of the ocean, water transparency is higher than near the coast. In the Sargasso Sea, water transparency is up to 67 m. During the period of plankton development, transparency decreases.
In the seas such a phenomenon as glow of the sea (bioluminescence). Glow in sea water living organisms containing phosphorus, primarily such as protozoa (nightlight, etc.), bacteria, jellyfish, worms, fish. Presumably the glow serves to scare away predators, to search for food, or to attract individuals of the opposite sex in the dark. The glow helps fishing vessels locate schools of fish in seawater.
Sound conductivity - acoustic properties of water. Found in the oceans sound-diffusing my And underwater "sound channel" possessing sound superconductivity. The sound-dissipating layer rises at night and falls during the day. It is used by submariners to dampen noise from submarine engines, and by fishing vessels to detect schools of fish. "Sound
signal" is used for short-term forecast of tsunami waves, in underwater navigation for ultra-long-distance transmission of acoustic signals.
Electrical conductivity sea water is high, it is directly proportional to salinity and temperature.
Natural radioactivity sea waters are small. But many animals and plants have the ability to concentrate radioactive isotopes, so seafood catches are tested for radioactivity.
Mobility — characteristic property liquid water. Under the influence of gravity, under the influence of wind, attraction by the Moon and the Sun and other factors, water moves. As it moves, the water is mixed, which allows waters of different salinity, chemical composition and temperature to be evenly distributed.
The ocean receives a lot of heat from the Sun. Occupying a large area, it receives more heat than land.
But the sun's rays heat only the top layer of water, only a few meters thick. Heat is transferred down from this layer as a result of constant mixing of water. But it should be noted that the water temperature decreases with depth, first abruptly, and then smoothly. At depth, water is almost uniform in temperature, since the depths of the oceans are mainly filled with waters of the same origin, forming in the polar regions of the Earth. At a depth of more than 3-4 thousand meters, the temperature usually ranges from +2°C to 0°C.
The temperature of surface waters also varies and is distributed depending on. The farther from the equator, the lower the temperature. This is due to the different amount of heat that comes from the Sun. Due to the spherical shape of our planet, the angle of incidence of the sun's ray at the equator is greater than , therefore they receive more heat than the polar ones. The highest ocean waters are observed at the equator - +28-29°C. To the north and south of it, the water temperature decreases. Due to proximity cold speed Temperatures drop slightly faster in the south than in the north.
The temperature of sea water also affects the surrounding areas. It is especially high in seas surrounded by hot ones, for example - up to 34°C, in the Persian Gulf - up to 35.6°C. In temperate latitudes, temperatures vary depending on the time of day.
The highest average temperature at the surface of the water is 19.4°C. Second place (17.3°C) is occupied by. In third place is , having an average temperature of about 16.5°C. The lowest water temperature in is on average slightly above 1°C. Consequently, for the entire World Ocean, the average temperature of surface waters is about 17.5°C.
So, the ocean absorbs 25-50% more heat than land, and this is its huge role for living beings on the entire planet. The sun heats its water all summer, and in winter this heated water gradually releases heat. Thus, it is something like the “central heating boiler” of the Earth. Without it, such severe frosts will come on Earth that all living things will die. It has been calculated that if the oceans did not conserve their heat so carefully, the average temperature on Earth would be -21°C, which is as much as 36°C lower than what we actually have.