What determines the temperature of the water in the ocean? Temperature and salinity of sea water What determines the temperature of surface waters.

Summer is known to be a fertile time for relaxation and sunbathing. But you want to swim, sunbathe and relax at any time of the year. And how long you have to wait for the heat and warm water in the water. Such dreams are especially relevant in the winter cold. Today you will not surprise anyone with New Year's trips in the real summer. With hot sun, hot sand and gentle sea of \u200b\u200bthe most amazing color. And there is such a possibility due to the temperature features of the World Ocean.

The world's oceans are much larger in area than land. Therefore, it is not surprising that it also accounts for much more solar heat. But even the sun's rays are not able to evenly and systematically warm it up completely. Only a shallow layer on the surface receives heat. Its thickness is only a few meters. But as a result of regular movement and stirring, heat can be transferred to the lower layers. And already at depths of 3-4 kilometers, the average water temperature remains unchanged and near the ocean floor is + 2-0C. Moreover, when diving to depths, the temperature of the water in the world's oceans first changes in sharp jumps, and only when it goes down, it begins to change in the direction of a gradual decrease.

The farther the distance from the equator is, the lower the water surface temperature becomes. This is obvious and directly related to the total amount of incoming warm sunlight. And since the Earth has the shape of a ball, the rays fall on it at different angles. Thus, the equator receives a lot more heat from the sun than both poles. Therefore, the water here regularly warms up to + 28C + 29C. This explains the higher temperature of tropical waters than the average of the World Ocean.

What determines the temperature of the world ocean

Considering why and how the water temperature changes, the climate and geographic location are of decisive importance. If the waters are surrounded by endless deserts, like the Red Sea, then they can warm up to + 34C. They are even higher in the Persian Gulf - up to + 35.6C. Moving away from the equator, warm currents begin to work. At the same time, cold masses are directed towards warm ones. Giant water masses are mixed. Wind is also capable of mixing surface layers. In this respect, of course, the example of the Pacific Ocean is indicative, occupying almost half of the entire World Ocean and a third of the entire planet Earth. So, in a state of a storm, the wind mixes the waters in the surface layer of the Pacific Ocean in southern latitudes to a depth of 65 meters. Mixing and dissolving, the average water temperature in the world's oceans is + 17.5C.

Considering the average temperature of the ocean water, we can state the following: the surface layer of the Pacific Ocean is the warmest + 19.4C. The second place went to the Indian + 17.3C. The temperature of the surface waters of the Atlantic Ocean + 16.5C - the third place. The champion in the coldest water - just above + 1C - is predictably the Arctic. But, despite the fact that the average temperature of the surface waters of the Pacific Ocean is the highest, due to its enormous size, there are areas in it where in winter it can drop to -1C (Bering Strait).

Influence of salinity

High salinity is a distinctive feature of the world's oceans. According to this criterion, it is many times superior to the indicators of water on land. Sea water contains 44 chemical elements, but the largest number among them is salt. To understand how much salt is in the oceans, you need to imagine the following picture - a layer of salt, evenly scattered over the land, will be 150 meters thick.

The salinity of the oceans can be arranged as follows:

• Atlantic is the saltiest - 35.4%;
• Indian in the middle peasants - 34.8%.
• The average salinity of the Tikhoi is the lowest - 34.5%.

The density directly depends on this. Thus, the average density of water in the Pacific Ocean is also lower than in others.

The maximum salinity of tropical waters is up to 35.5-35.6 ‰ higher than the average of the World Ocean.

Why and how does water salinity change? There are several reasons for the existing difference:

• Evaporation;
• Ice cover formation;
• Decrease in salinity, with precipitation;
• River waters flow into the world ocean.

Near the continents, at short distances from the coast, the salinity of the waters is not as high as in the center of the ocean, since they are affected by desalination of river flows and melting of ice. And the increase in salinity is actively promoted by evaporation and the formation of ice.

For example, the Red Sea has no rivers flowing into it, but there is a very high evaporation rate due to strong solar heating and low precipitation. As a result, the salinity is 42% o. And if we take into consideration the Baltic Sea, then its salinity does not exceed 1% and it is, in fact, very close to the indicators of freshwater. This is explained by the fact that it is located in a climate with very low evaporation and the highest rainfall.

What is the best water temperature for swimming

On the shore of any sea it is very difficult to resist the desire to swim. The sea, waves, sand act as tempters. But someone is tempted by the opportunity to dive into a winter ice-hole, while someone will enjoy bathing exclusively at a water temperature of at least + 20C. Everything is very individual in this world. But there is also an ordinary average person who will be happy with the usual average swimming in a pond. The normal temperature is considered to be +22 - + 24C. It is important to understand that when immersed in water, the human body is affected not only by the temperature of the surrounding liquid, but also by factors such as:

1. Sun rays and air temperature;
2. Pressure;
3. The power of sea waves.

Yet the human body is capable of adapting to numerous changes in the external environment. It can either be hardened or relaxed through the thermoregulation process. Therefore, the statement, there is nothing better than lukewarm water, is not always and not entirely correct. Very warm waters promote the development and reproduction of a huge number of harmful microorganisms and unpleasant infections. Bathing in such conditions poses a threat not only to children, but also to adults. Therefore, it is quite reasonable that residents of different continents and regions of habitation have exclusively their own comfort zone for swimming. Here we can cite as an example the inhabitants of the Greek coast with a water temperature not lower than + 25C, or those who live on the shores of the Baltic Sea, where, by definition, it does not exceed + 20C.

What is the best temperature for pregnant women

For expectant mothers, as well as for young children, warm water is most suitable for bathing. Sea baths are often chosen for this. The recommended temperature during pregnancy should not be lower than + 22C. She is the most natural and safe and does not pose any threat. Nevertheless, it is important for expectant mothers to remember that, while maintaining the temperature balance, it is necessary to avoid direct sunlight and it is advisable to avoid possible heat drops. And no matter how much you like being in the arms of warm sea waves, you should not abuse a long bathing. It is believed that the optimal duration of water procedures for pregnant women should not be more than 15-20 minutes.

By absorbing enormous amounts of heat, the ocean makes life possible on the planet. This reflects its pricelessness and necessity for all life on Earth. The sun in a certain period heats the World Ocean, and in the next period, warm water gradually warms the atmosphere with this heat. Without this process, our planet will plunge into the most severe cold, and life on Earth will perish. Scientists have calculated that without the heat stored by the world's oceans, the average earth's temperature will drop to -18C or -23C, which is 36 degrees lower than the usual one today.

Instructions

The average salinity of the World Ocean is 35 ppm - this figure is most often called in statistics. Slightly more accurate value, without rounding: 34.73 ppm. In practice, this means that about 35 g of salt must be dissolved in each liter of theoretical ocean water. In practice, this value varies quite a lot, since the World Ocean is so huge that the waters in it cannot quickly mix and form a space that is homogeneous in terms of chemical properties.

The salinity of the ocean depends on several factors. First, it is determined by the percentage of water evaporating from the ocean and precipitation falling into it. If there is a lot of precipitation, the level of local salinity decreases, and if there is no precipitation, but the water evaporates intensively, then the salinity increases. Therefore, in the tropics, in certain seasons, the salinity of waters reaches record values \u200b\u200bfor the planet. The most part of the ocean is the Red Sea, its salinity is 43 ppm.

Moreover, even if the salt content on the surface of the sea or ocean fluctuates, usually these changes practically do not affect the deep layers of water. Surface fluctuations rarely exceed 6 ppm. In some areas, the salinity of the water decreases due to the abundance of fresh rivers flowing into the seas.

The salinity of the Pacific and Altantic oceans is slightly higher than the rest: it is 34.87 ppm. The Indian Ocean has a salinity of 34.58 ppm. The lowest salinity is in the Arctic Ocean, and the reason for this is the melting of polar ice, which is especially intense in the Southern Hemisphere. The currents of the Arctic Ocean also affect the Indian, which is why its salinity is lower than that of the Atlantic and Pacific Ocean.

The farther from the poles, the higher the salinity of the ocean, for the same reasons. However, the saltiest latitudes are between 3 and 20 degrees in both directions from the equator, not the equator itself. Sometimes these "stripes" are even said to be salinity belts. The reason for this distribution is that the equator is a zone of constant heavy torrential tropical rainfall, which desalinates the water.

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Not only salinity changes, but also the temperature of the water in the World Ocean. Horizontally the temperature changes from the equator to the poles, but there is also a vertical change in temperature: it decreases with depth. The reason is that the sun is not able to penetrate the entire water column and heat the ocean waters to the very bottom. The surface temperature of the waters varies greatly. In the equator, it reaches + 25-28 degrees Celsius, and near the North Pole it can drop to 0, and sometimes it is slightly lower.

Useful advice

The area of \u200b\u200bthe oceans is approximately 360 million square meters. km. This is about 71% of the entire planet.

1. What determines the salinity of ocean waters?

The oceans - the main part of the hydrosphere - is a continuous watery shell of the globe. The waters of the World Ocean are heterogeneous in composition and differ in salinity, temperature, transparency and other features.

The salinity of waters in the ocean depends on the conditions of evaporation of water from the surface and the influx of fresh water from the surface of the land and with atmospheric precipitation. Evaporation of water occurs more intensely in equatorial and tropical latitudes and slows down in temperate and circumpolar latitudes. If we compare the salinity of the northern and southern seas, then it can be established that the water in the southern seas is saltier. The salinity of waters in the oceans also varies depending on the geographic location, however, in the ocean, mixing of water occurs more intensively than in more enclosed seas, therefore, the difference in the salinity of the ocean water masses will not be too sharp, as in the seas. The most saline (over 37% o) are ocean waters in the tropics.

2. What are the differences in ocean water temperatures?

The temperature of the water in the World Ocean also varies depending on the geographical latitude. In tropical and equatorial latitudes, the water temperature can reach + 30 ° С and higher, in the polar regions it drops to -2 ° С. At lower temperatures, ocean water freezes. Seasonal changes in ocean temperature are more pronounced in the temperate climatic zone. The average annual temperature of the World Ocean is 3 ° C higher than the average land temperature. This heat is transferred to land through the air masses of the atmosphere.

3. In what areas of the ocean does ice form? How do they affect the nature of the Earth and human economic activity?

The waters of the World Ocean freeze in arctic, subarctic and partly in temperate latitudes. The resulting ice cover affects the climate of the continents, making it difficult to use cheap sea transport in the north for transporting goods.

4. What is called the water mass? What are the main types of water masses? What water masses are emitted in the surface layer of the ocean?

You will find the definition of the concept of water masses in the textbook (9).

Water masses, by analogy with air masses, are named according to the geographic zone in which they formed. Each water mass (tropical, equatorial, arctic) has its own characteristic properties and differs from the rest in salinity, temperature, transparency and other characteristics. Water masses differ not only depending on the geographic latitudes of their formation, but also depending on the depth. Surface waters differ from deep and bottom waters. The deep and bottom waters are practically not affected by sunlight and heat. Their properties are more constant throughout the World Ocean, in contrast to the surface hearth, the properties of which depend on the amount of heat and light received. There is much more warm water on Earth than cold water. Residents of temperate latitudes spend their New Year holidays with great pleasure on the coasts of those seas and oceans where the water is warm and clean. Sunbathing under the hot sun, swimming in salty and warm water, people recuperate and strengthen their health.

The ocean receives a lot of heat from the Sun - occupying a large area, it receives more heat than land. Water possesses high heat capacitytherefore, a huge amount of heat accumulates in the ocean. Only the top 10-meter layer of ocean water contains more heat than the entire layer. But the sun's rays heat only the top layer of water; heat is transferred down from this layer as a result of constant stirring water... But it should be noted that the water temperature decreases with depth, first abruptly, and then gradually. At depth, the water is almost uniform in temperature, since the depth of the oceans is mainly filled with waters of the same origin, which form in the polar regions of the Earth. At a depth more than 3-4 thousand meters, the temperature usually ranges from + 2 ° C to 0 ° C.

So, the ocean absorbs heat 25-50% more than land. The sun heats the water all summer, and in winter this heat enters the atmosphere, therefore, without the World Ocean, such severe frosts would come on Earth that all life on the planet would perish. This is its huge role for the living creatures of the Earth. It was calculated that if the oceans did not keep warm so carefully, the average temperature on our planet would be -21 ° С, which is 36 ° lower than what we have now.

Water temperature The world's oceans are not the same in different places in total, the oceans are heated in strips of about 20 ° N and

20 ° w, which coincide with high pressure areas. This is due to low cloud cover at subtropical, tropical and subequatorial latitudes. The oceans absorb heat mainly in the belt 30 ° S - 20 ° S, and give it to the atmosphere at high latitudes. This is an important factor in climate mitigation in temperate and polar latitudes during the cold season of the rockery rock.

Only the top layer of water 1 cm thick collects solar heat. It absorbs 94% of the solar energy that hits the ocean surface. Solar energy is transmitted from the surface to the interior. The main role in this vidig is played by dynamic processes due to various reasons. All together, the dynamic processes (vertical and horizontal movements of water) determine well the transfer of heat from the surface to different depths. Thanks to this, the waters of the oceans. Profit in its entire thickness and concentrate a huge amount of heat.

Average surface water temperature. The oceans are 17.54 °. C (air temperature over the ocean 14.4 ° C). The average temperature of water on the surface in the northern and southern polar regions, the state sets, respectively, -0.75 and -0.79 °. C, in the equatorial strip 26.7 °. C and 27.3 °. NW Northern Hemisphere water temperature is higher than in. South, due to the influence of the continents.

At great depths, the distribution of temperatures is determined by the deep circulation of water, which plunged in high latitudes, have a lower temperature than plunged in low latitudes. In the bottom layer, the temperature varies from 1.4 to 1.8 °. From at low latitudes to 0 °. From and below to high.

The salinity of ocean water is one of its most important features.

Water is the best solvent. Although it is weak (contains about 4% by weight of the dissolved solid), the solution is very rich in quality composition. All known elements are dissolved in water, however, they are in meager quantities, but in total they give significant values. Suffice it to say that, in addition to a huge amount of basic salts - NaCl, MgSO, MgCgCl 2, about 8 million tons of gold, 80 million tons of nickel, 164 million tons of silver, 800 million tons of molybdenum, and 80 billion tons of iodine are dissolved in seawater. etc.

In addition to solid matter, gases (oxygen, nitrogen, carbon dioxide, and hydrogen sulfide in stagnant waters) and organic matter are also dissolved in water

The salinity of sea water determines the temperatures of its freezing and the highest density, and the duration of the processes of mixing water in the oceans depends on them. Consequently, it affects air temperature and climate. Earth mlі.

Salinity c. The distribution of the world's oceans is uneven and depends mainly on the ratio of evaporation and precipitation in the polar and subpolar regions, where water is desalinated by melting ice, the salinity is less: c. In the Arctic, it is equal on average to 31.4 ‰ century. Antarctica - 33.93 %% о.

In temperate latitudes, salinity is close to normal (average) and is about 35 ‰. This is due to the intense mixing of m water in these latitudes. The highest salinity in the open ocean is in the kiln latitudes of both hemispheres (where evaporation prevails over precipitation) - more than 37.25 ‰. In the equatorial zone, through desalination by precipitation, it is slightly below average. Highest salinity. The world's oceans in the closed seas of the tropical zone - more than 42 ‰ (Red Sea). Salinity changes very little with depth.

67 Water movement in the oceans Sea currents

Sea currents are gradual movements of water masses in the oceans and seas, caused by various forces (gravitational, friction and water-generating). They play a significant role in life. World Ocean and Navigation; encourage the exchange of water masses, change of banks (destruction, reclamation of new land), shallowing of port waters, ice transfer, etc.; great influence on the climates of different parts of the world: for example, systems. The North Atlantic Current softens the climate. Europe. Sea currents differ: by origin - sea currents caused by wind friction against the sea surface (wind currents), uneven distribution of water temperature and salinity (current density), level slope (runoff currents), etc .; according to the degree of stability - stable, changing, temporary, periodic (for example, seasonal currents that change directions under the influence of monsoons); according to placement - surface, subsurface, intermediate, deep, bottom; by physical and chemical properties - warm, cold, desalinated, saline.

The direction of sea currents is influenced by rotation. Earth that deflects currents in. Northern Hemisphere - to the right, c. South - left

The main surface currents are influenced by trade winds that blow over the oceans all year round

Consider currents. Pacific Ocean. The current, which appears under the influence of the north-east trade wind, forms an angle of 45 ° with it, deviating to the right along the prevailing wind direction. Therefore, the current goes from east to west up to the east of the equator, slightly north of it. This current creates a northeast trade wind. They call her. North trade wind.

The south-east trade wind forms. South trade wind current, which deviates from the trade wind direction 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. The trade wind (equatorial) currents, running parallel to the equator, reach the eastern coast of the continents and branch, with one stream returning along the coast to the north, and the second to the south. South branch. North. Trade wind and northern branch. South. Tradewind current. They go to meet each other. Having met, they merge and go through the zone of equatorial calm from west to east, forming an equatorial countercurrent.

Right branch. North. The trade wind flows northward along the eastern coast of the mainland as a result of rotation. On the earth, it gradually deviates from the coast and, about the 40th parallel, turns to the east into the open ocean. Here it is picked up by the south-westerly winds and forced to go from west to east. Having reached the western coast of the mainland, the current forks, its right branch goes to the south, deviating by rotation. Lands to the right, and therefore moves away from the coast. Reaching. North trade wind (equatorial) current, this branch merges with it and forms a closed northern equatorial circle.

The left branch of the current is directed to the north, deflected by rotation. Lands to the right, nestles against the western coast of the mainland and goes along it

The northeastern winds blowing from the circumpolar space also create a current. She, carrying very cold water, goes south along the eastern shores of the mainland. Eurasia

In the southern hemisphere, left branch. South. The trade wind flows south along the east coast. Australia, rotating. The land swings to the left and is pushed back from the coast. At the 40th parallel, this branch of the current returns to the open ocean, jumps up with northwestern winds and goes from west to east. Off the western shores. America's current forks. The left branch returns along f. Rega of the mainland to the north. Swinging by rotation. Land to the left, this current departs from the shore and joins with. South trade wind current, forming the southern equatorial ring of currents. On the right branch, I go past the southern tip. America runs east into the neighboring ocean.

Especially terrible are the waves arising from earthquakes and volcanic eruptions when the waters fall on the shore. Waves of this origin are called tsunamis.

As a result of the action. Moon to the surface. The world's oceans ebb and flow. There are very high tides in the bay. Saint-Malo in. France - up to 15 m.At the top of the bay, the tide height can reach 18 m.

In the southern part. Atlantic Ocean high tides - up to 12-14 m - can be observed off the coast. Patagonia north of the entrance to. Strait of Magellan

In the Pacific Ocean the greatest tides are in. Sea of \u200b\u200bOkhotsk off the coast. Of Russia

In the Indian Ocean, high tides occur off the western shores. India (up to 12 m)