The topic of the second assignment on geography in the Unified State Exam format sounds like "Lithosphere. Atmosphere. Hydrosphere."
To complete this task, you need to know the salinity of most seas, the percentage composition of the atmosphere, be able to correlate temperature changes with an increase or rise in the earth's surface above sea level, and be aware of the dependence atmospheric pressure from the height of the earth's surface, distinguish between relative and absolute humidity.
Required theory:
To begin with, it is worth clarifying that the task is divided into many subtypes, which becomes clear from its name. Therefore, the theory and procedure for performing the work vary significantly.
1 task type: Atmosphere pressure.
The lower the earth's surface is to sea level, the higher the atmospheric pressure.
2nd task type: salinity of the seas.
Tropical seas are saltier than northern ones.
In general, it is better to memorize a ready-made table of salinity of the seas than to try to remember which of them can be classified as tropical and which not. Personally, I remembered one of the mnemotic rules when writing a story, somehow using the names of the seas in it. You can come up with your own more effective way.
The table below does not list all the seas, but I didn’t see any seas other than them on the samples.
TABLE OF SALINITY OF THE SEA:
Red sea
Mediterranean Sea
Barents/Caribbean/North Seas
Japanese Sea
Sea of Okhotsk
Bering Sea
Black Sea
Baltic Sea
Caspian Sea
41.5 ppm
39.5 ppm
35 ppm
34 ppm
32 ppm
up to 32 ppm
up to 18 ppm
15 ppm
13 ppm
3 type of task: percentage of gases in the atmosphere.
Naturally, there are quite a lot of gases in the atmosphere, and the percentage of some of them is very small. It’s worth remembering the ones highlighted in bold; I personally never came across the rest in test assignments.
PERCENTAGE CONTENT OF GASES IN THE ATMOSPHERE:
Nitrogen
Oxygen
Carbon dioxide
Hydrogen
4th task type: dependence of air temperature on the rise of the earth's surface above sea level.
The higher the earth's surface is above sea level, the lower the air temperature.
5 task type: relative and absolute humidity air.
Absolute humidity - water vapor content in 1 m^3 air [g]
Relative humidity [%]
This task can also be divided into subtypes, so everything should be shown clearly.
1. If the relative humidity in the table is the same, but it is necessary to determine the temperature, then:
The higher the absolute humidity (g), the higher the temperature.
2. If the air temperature in the table is the same, but it is necessary to determine relative humidity air, then:
The more water vapor, the higher the relative humidity.
3. If the absolute humidity in the table is the same, but it is necessary to determine the air temperature, then:
The higher the relative humidity, the lower the air temperature.
Examples of the five Task Types:
1. atmospheric pressure.
At the points indicated by numbers in the figure, atmospheric pressure measurements are simultaneously taken. Arrange these points in order of increasing atmospheric pressure (lowest to highest).
The task can also be presented in the form of a table or graph, but the principle of its implementation does not change.
2. salinity of the seas.
Arrange the seas in order of decreasing salinity of surface waters (from highest to lowest).
1) Barentsvo;
2) Black;
3) Mediterranean.
3. percentage of gases in the atmosphere.
Arrange the gases in order of increasing their content in the atmospheric air (from lowest to highest).
1) Oxygen;
2) Nitrogen;
3) Hydrogen.
4. dependence of air temperature on the rise of the earth's surface above sea level.
At the points indicated by numbers in the figure, air temperature measurements are simultaneously taken. Arrange these points in order of decreasing air temperature (from highest to lowest).
The task can also be presented in the form of a table or other graph, but the principle of its implementation does not change.
5.2. relative and absolute air humidity.
(The air temperature is the same, but the absolute humidity is not).
At the points indicated in the table by numbers, measurements of the water vapor content in 1 m^3 of air and temperature are simultaneously carried out. Arrange these items in order of increasing relative humidity (lowest to highest).
5.3. relative and absolute air humidity.
(absolute humidity is the same, but relative humidity is different).
At weather stations 1, 2 and 3, the water vapor content in 1 m^3 of air is simultaneously measured and the relative humidity of the air is determined. The obtained values are shown in the table. Arrange these weather stations in order of the increase in air temperature at them at the time of taking these measurements (from lowest to highest).
Salinity is the amount of dissolved solid minerals (salts), expressed in grams, in 1 kg of sea water. The thousandth part of a whole is called ppm and is indicated by the symbol %o. For example, if the salinity of ocean water is 35%o, this means that 1 kg (1000 g) of this water contains 35%o (ppm) of dissolved substances.
Salinity is one of the main characteristics of sea water; its value expresses the degree of concentration of all substances dissolved in water (mainly salts).
The amount of salinity in a particular area of the World Ocean depends on a number of factors: the influx of fresh water and the amount atmospheric precipitation, the intensity of water evaporation, the formation and melting of ice and water mixing processes.
As seawater evaporates, the salinity of seawater increases as the salts remain in solution. When melting sea ice salinity decreases because sea ice tends to have less salinity than 
salinity of surrounding waters.
When sea ice forms, salinity increases due to the fact that only part of the salts pass into the ice.
What is the salinity of the waters of the World Ocean and its geographical distribution?
Salinity in different places, both on the surface and in the depths of oceans and seas, is not the same. The average salinity of the waters of the World Ocean is 35%. 
In the open parts of the oceans, salinity changes little (from 32 to 37.9%o), in the seas it varies significantly more - from 2 (in the Gulf of Finland of the Baltic Sea) to 42%o (in the Red Sea).
The general pattern of changes in salinity across latitudes under the influence of precipitation and evaporation regimes is typical for all oceans: salinity increases in the direction from the poles to the tropics, reaches a maximum value around 20-25° northern and southern latitudes and decreases again in the equatorial zone.
The uniform change in salinity in the surface layers is disrupted by the influence of oceanic and coastal currents and enrichment 
fresh waters of large rivers. The highest salinity of the World Ocean (S = 37.9%o, not counting some seas, is west of the Azores.
The salinity of the seas differs more from the salinity of the ocean, the more less sea communicate with him; it also depends on their geographical location, in particular from climatic conditions. The salinity of the seas is greater than that of the oceans: the Mediterranean - in the west 37-38%0, in the east - 38-39%0;
The salinity of the Red Sea is 37%o in the south, and up to 42%o in the north, in Persian Gulf in the north the salinity is 40%o, in the eastern part - from 37 to 38%o.
Salinity: in the Sea of Azov in the middle part is from 10 to 12%o, and off the coast - 9.5%o. 
The salinity of water in the Black Sea, in the middle part, is from 10 to 12%o, and in the northwestern part - 17%o, with increasing depth of the sea, the salinity of the water increases to 22%o;
in the Baltic Sea with eastern winds - 10%o, with western and southwestern winds - from 10 to 22%o; in the Gulf of Finland near the island of Kotlin - 2%0; in the White Sea on the border with the Barents Sea it is 34-34.5%o, in Gorlo - 27-30%o, and in the middle part - from 24 to 27%o.
In the Caspian Sea, salinity is 12.8% o and in 
The average salinity of the Aral Sea is 10.3%.
The salinity of the Russian Arctic and Far Eastern seas in areas remote from the coast is 29-30%.
With increasing depth, salinity changes only up to 1500 m, below this horizon and to the bottom - insignificantly and ranges from 34 to 35%.
In the polar regions, when ice melts, salinity increases with depth; when ice forms, the salinity of sea water decreases. 
In temperate latitudes, the salinity of sea water varies little with depth, in subtropical zone it quickly decreases to a depth of SOO-1500 m, in the tropical it increases to a depth of 100 m, then decreases to a depth of 500 m, after which it increases slightly to a depth of 1500 m, and below remains unchanged.
What is the significance of the salinity and density of sea water?
As the temperature decreases, the density of salty sea water increases, that is, the sea is saltier in winter than in summer! During autumn and winter cooling, the water on the sea surface becomes denser and heavier. 
With further cooling, surface sea water, being denser and heavier, “sinks” and mixes with warmer and lighter deep water.
This feature of salty sea water helps to moderate the Earth's climate. When cooling 1 cu. see sea water at 19C 3134 cubic meters. see the air heats up by 1 °C.
The salinity of sea water increases vertical circulation in the oceans and seas. The air receives much more heat (thermal energy) from the salty waters of the World Ocean than it would receive if the ocean waters were fresh.
The intensity of freezing of sea water and the development of ice phenomena in the seas and oceans. 
The horizontal and vertical distribution of seawater density promotes horizontal and vertical water circulation.
Knowing the vertical distribution of the density of sea water, it is possible to determine the direction and speed of currents, as well as the stability of a particular water mass: if the mass is unstable, then denser water lies above less dense water, and the waters will mix (vertical circulation). 
The density of sea water is great importance for the inhabitants of the ocean. The stability of the water composition, which affects the distribution of organic and inorganic matter in the ocean, depends on it.
The density of water affects the draft of ships. When moving from ocean water to fresh water and vice versa, their draft can change up to 0.3 m. Therefore, for proper loading of ships in 
ports and ensuring the safety of navigation, it is necessary to know the value of salinity and density at the port of loading and at the transition to the sea to the port of destination and take them into account correctly.
The Earth can be confidently called a water planet, because the World Ocean surrounding the land covers 71% of its entire surface. , included in its composition, differ from each other in many ways. Including such a parameter as salinity, which means the amount of salts dissolved in one liter of water under certain conditions. The salinity of sea water is most often measured in “‰” (ppm). Now it won’t be difficult to find out which is the saltiest sea on Earth.
5. Ionian Sea - salinity exceeds 38 ‰
The Ionian Sea is the part of the Mediterranean that washes the shores of southern Italy and Greece. The bottom of the sea is covered with silt, and closer to the shores - with sand and small shell rock. Its area is 169 thousand km², maximum depth is 5,121 m. This is the most great depth throughout the Mediterranean Sea. Commercial fishing of mackerel, mullet, tuna, and flounder is carried out. Water Ionian Sea safe and very warm, even in February their temperature does not fall below 14°C, and at the peak of the holiday season, in August, reaches 25.5°C. Among its inhabitants are bottlenose dolphins, huge turtles, and octopuses. And very dangerous sea urchins and white sharks can hardly be found near the coast. Poisonous dragon fish, which can cause an allergic reaction in humans, are more active at night and burrow into the sand during the day.
4. Aegean Sea - salinity from 37 to 40.0 ‰
This semi-enclosed sea has about 20,000 islands and is located in the eastern Mediterranean. The total area is 179 thousand km². Through the straits it is connected to Mramorny, Cherny and Mediterranean seas. The salinity of its waters is increasing, which is associated with global warming. After swimming, it is recommended to rinse off the sea water, as this can negatively affect the condition of the skin and mucous membrane of the eyes. There is a fishing industry in the Aegean Sea; sponges are actively mined and octopuses are caught. Due to the fact that there is little plankton in this sea, fishing in its waters is gradually declining.
3. Ligurian Sea - salinity 38 ‰
This sea is located in the western part of the Mediterranean. The shores are steep and rocky, but there are sandy beaches. Many small rivers flow into the Ligurian Sea, which originate in the Apennines. On its shores there are such important ports as:
- Limpia, which is considered the sea gate of Nice.
- Cruise ports of Savona, La Spezia, with container and bulk terminals.
- Genoese port, ranking first in terms of trade volume in Italy.
Despite high salinity These waters, on the French-Italian coast of the Ligurian Sea, is located one of the most famous resort areas in the world - the Riviera.
2. Mediterranean Sea - salinity from 36 to 39.5 ‰
The Mediterranean Sea is a relic of the ancient Tethys Ocean. It is considered one of the largest seas in size, its area is 2.5 million km². Its basin includes the Sea of Azov, Black and Marmara. The salinity of the sea fluctuates significantly, as water with a much lower salinity enters from the Atlantic through the Strait of Gibraltar. The amount of zooplankton in the Mediterranean Sea is relatively small, and as a result there are few various types fish, as well as marine animals and mammals. But algae are present in large numbers, especially peridinea and diatoms. The bottom fauna is very poor due to yellowish silt, which is not conducive to the development of life. There are 550 species of fish in the Mediterranean Sea, 70 of which are endemic. The most common species are: mackerel, sardine, horse mackerel, mullet, etc. There are also larger “inhabitants” - sharks, rays, tuna. Edible shellfish are common.
1. Red Sea - salinity 41 ‰
The saltiest of all, the Red Sea is located in a tectonic depression, the depth of which can reach 3 km. Is an inland sea Indian Ocean. The hot climate, which provokes strong surface evaporation and low precipitation (about 100 mm per year), and the absence of rivers flowing into the sea, leads to a gradual increase in its salinity. Due to the absence of silt and sand, which are abundant in river water, the Red Sea is distinguished by its extraordinary transparency and cleanliness. The water temperature even in winter is +20 °C, and in summer it is much higher.
Despite its salinity, the waters of the Red Sea amaze with the huge number of different species of fish living in it. But ichthyologists believe that only 60% of fish capable of existing at great depths have been discovered. The sea is extremely beautiful, and it has many interesting and sometimes funny inhabitants, but touching them is strictly prohibited. Corals, sponges, jellyfish, and sea urchins, moray eels and poisonous sea snakes potentially extremely dangerous. Any contact with them can result in a burn, significant blood loss or severe allergic reaction, and sometimes fatal. 44 species of sharks live in warm sea waters. The most terrible of them is the tiger, which can easily attack a person.
Having examined them separately, it is now easy to conclude which is the saltiest sea. The saltiness of the very famous Dead Sea reaches 350 ‰, but in fact, despite the name, it is an endorheic lake that is gradually drying up.
Everyone knows that sea water tastes salty. But not everyone knows that the amount of salt in different seas and oceans, like chemical composition saline solution, differs significantly.
In some seas there is relatively little salt, in others, on the contrary, the water is saltier than usual.
How is sea salinity measured?
In order to find out which sea has the saltiest water, scientists, of course, do not taste it while traveling through different seas of the planet. Everything is much simpler: the salinity of sea water is measured by determining how much salt is contained in one liter of water. To do this, you just need to evaporate the water and weigh the remaining salt.
If we do this experiment with ordinary tap water, we will get about 1.5 - 2 grams of salts in the dry residue, which add flavor. Distilled water, which does not contain salts, is absolutely tasteless, unlike ordinary water. drinking water.
Sea salt, obtained by evaporating sea water, consists not only of table salt, known to everyone, but also of large quantity other salts and minerals: sulfates, bicarbonates, borates, etc. In fact, in sea water you can find almost the entire periodic table of elements.
About 80 seas and oceans are marked on the map of our planet, and in each of them the salt concentration is at its own level. Moreover, different parts of the same sea have different salinity: where it flows into the sea large river, decreases sharply. The Baltic Sea is the least salty in the world: the amount of salt in a liter of its water barely reaches 7 grams.
The saltiest sea on the planet
Sometimes in popular literature there is a statement that the Dead Sea is considered the saltiest in the world. In fact, this is not true, and here's why: The Dead Sea is not actually a sea, but a lake. 
It is not connected to the World Ocean by any strait, river or canal, therefore, from a geographical point of view, it is a lake. Therefore, in terms of salinity level, it should be compared with other salty lakes on the planet, and not with the seas.
In fact, the Red Sea is the saltiest, with water containing about 41 grams of salt for every liter. This is a very high figure that the waters of the Red Sea were able to achieve due to the hot, arid climate of the shores. Not a single river flows into it; the level of the Red Sea is replenished only due to the flow of water from the Gulf of Aden.
The evaporation of water is very high, and the incoming water is less salty water does not have time to dilute the brine. The neighboring Mediterranean Sea, to which the Red Sea is connected via the Suez Canal, has a salinity of only about 26 grams per liter of water.
The waters of the Red Sea are striking in their purity and transparency, since not a single river flows into it, bringing with it river silt and fine sand. Despite the rather serious depth (about 3 kilometers in the deepest part), it warms up well sun rays, and even in winter its temperature does not fall below 20 degrees, and in summer it stays at 27-28 degrees. 
This ideal conditions for the reproduction of numerous sea fish, animals, shellfish and other underwater creatures. Undersea world The Red Sea is extremely rich and diverse, despite the high salinity of the water.
The saltiest seas in Russia
Most salty sea, washing the shores of Russia is the Barents Sea, the salt content of which reaches 35 grams per liter of water. It is located in the northern part of the country, so in winter it is almost completely covered with ice. Only one remains free small area sea in the southwestern part.
Even in summer, the water temperature does not exceed 12 degrees Celsius. Despite this, the Barents Sea is rich in fish, among which there are many commercial species - perch, herring, capelin, catfish, beluga, etc. 
The other northern seas of Russia are slightly inferior in salinity to the Barents, but are also among the top ten most saline seas in the world. These are the Laptev Sea (34 grams of salt per liter), the Chukchi Sea (33 grams of salt per liter) and the White Sea (30 grams of salt per liter of water).
When schoolchildren ask which sea is the saltiest, many adults answer without hesitation: “Red.” The answer, unfortunately, is not entirely correct.
The Red Sea is indeed very salty. Located in tectonic
In the depression between Africa and Africa, the reservoir washes the shores of several countries at once: Egypt, Israel, Saudi Arabia, several others. Not a single river flows into it, almost no precipitation falls over it (100 mm annually cannot be taken into account). But evaporation exceeds 2000 mm per year. This imbalance causes increased formation in the Red Sea, which is considered the saltiest in the entire world's oceans. Each liter of water contains 41 milligrams of salt. The water is so salty that ships that sank many years ago still lie on the bottom, indestructible: salt prevents harmful microorganisms from developing. Science officially confirms: the Red Sea is the saltiest sea in the world.
But, some will argue, the water in the Dead Sea is much saltier. It is known that the amount of salt in each liter from this reservoir ranges from 200 to 275 milligrams per liter of water. It turns out that the Dead Sea is the saltiest sea on the planet. After all, everyone knows: the water in it is so “thick” that it is even impossible to dive. And due to the salinity of the water, swimming is allowed only where there is running water (showers): salt that gets into the eyes can cause burns to the mucous membranes and blindness.
This is also correct.
But... officially the Dead Sea... is not a sea at all! It is large, very salty, incredibly beautiful, and has a powerful healing power…lake! Its length is less than 70 km, and its width does not exceed 18 kilometers.
To the lake called Dead Sea, only the Jordan River flows into it. Gradually evaporating, the water retreats further and further from the line of the original shore. If this continues, scientists believe, in a few centuries only salt deposits will remain from this reservoir.
So, let's summarize. The saltiest sea on Earth is the Red Sea. This official information is registered in all scientific reference books. The Dead Sea, despite the fact that its waters contain much more salt, is not even the most salt lake on the planet. It is ahead of Lake Assal located in Djibouti. Its salinity is 35%, while its “rival” has only 27%.
The saltiest sea in the Russian Federation is the Sea of Japan. The salinity in it is distributed unevenly. Thus, in Peter the Great Bay it reaches 32%, and in other places it decreases slightly.
There is one in Russia, Lake Baskunchak. The salinity of its water is 37% (and in some places - 90%).
In fact, the lake is a large depression at the very top of the salt mountain, whose “roots” go several hundred meters underground. There are also resorts on Lake Baskunchak, but it is known to others: it is the largest place in the world for extracting the purest salt.
The lion's share of the lake's surface is a salt crust on which you can walk. Swimming here is difficult: the “thick” water does not allow you to dive into it and leaves a noticeable salt trace on the skin. However, it is believed that dosed swimming in the lake is as beneficial as in the Dead Sea.