X International Distance Olympiad "Erudite". Geography

Tasksschool tour of the Geography Olympiad

7th grade last name, first name_________________________________

When answering questions and completing assignments, do not rush, since the answers are not always obvious and require not only knowledge of the program material, but also general geographical erudition.

Good luck in your work!

1. Determine the geographical coordinates of the city of Cape Town (southern Africa)_________________

2. Convert the numerical scale to a named scale of 1:30000000__________________________

3. “The most, the most” (world records)

4) the highest waterfall_______________________________________________________________

5) the deepest lake_______________________________________________________________

6) the coldest continent_______________________________________________________________

7) the widest strait______________________________________________________________

8) the largest lake_______________________________________________________________

9) the smallest continent_______________________________________________________________

10) the saltiest place in the World Ocean________________________________________________

4 . Explain what the terms mean?

1) Laurasia _________________________________________________________________

2) Passat ______________________________________________________________

3) Meridian __________________________________________________________

4) Azimuth ______________________________________________________________

(for each correct answer 2 points)

5. Are there any points on Earth that require only latitude to locate them? If yes, then name them. ________________________________

(5 points)

6. The name of this object comes from the word “masunu”, which means “big water” in the Indian language. What is this object? _______________________________________

7. From the Tibetan language this name is translated as “goddess - mother of the Earth.” What is it

_____________________________________________________________________________

8. Which concept does the following associations belong to:

1) wave, earthquake, danger, speed, disaster ________________________

2) rocks, rapids, spectacle, roar, water _____________________________________

3) ocean, ice, mountain, danger _____________________________________________

(for each correct answer 2 points)

9. How can we explain the fact that the most abundant rivers in the world flow in the equatorial belt? ______________________________________________________________

(5 points)

10. Student Vanya Stepochkin did not prepare homework for any subject. He explained to all the teachers that yesterday after school, while walking along the beach, he saw how the wind was carrying a little girl on an inflatable mattress into the open sea. Naturally, he rushed to save her, but after what happened, he had no time for lessons. All the teachers praised him, except the geography teacher. What made the geography teacher doubt the sincerity of the boy’s words?_________________________________________________

(15 points)

11. Choose the correct statements

1. The South Pole is colder than the North Pole
2. The Bering Strait was discovered by Vitus Bering
3. The map is on a larger scale than the topographic plan
4. Azimuth to East means 180 degrees
5. The largest island in the world is Sakhalin
6. The highest peak in the world is called Chomolungma
7. In the south, Eurasia is washed by the Indian Ocean

12. Solve a geographic problem.

An oil driller, a scuba diver, a polar explorer and a penguin argued - who is closer to the center of the Earth? The scuba diver says: “I will sit in the submersible and descend to the bottom of the Mariana Trench, its depth is 11022 m, and I will find myself closest to the center of the Earth.” The polar explorer says: “I will go to the north pole and will be closest to the center of the Earth.” The driller says: “I will drill a well in the Persian Gulf 14 km deep and I will be closest to the center of the Earth.” Only the penguin doesn’t say anything, he just lives in Antarctica (the height of Antarctica is 3000 m, the height of the ice sheet is 4 km). Which character is closest to the center of the Earth? ______________________________________ (10 points)

13.

(for each correct answer 2 points)

14. The air is heated by the underlying surface; in the mountains, this surface is located closer to the Sun, and, therefore, the influx of solar radiation as it rises should increase and the temperature should increase. However, we know that this does not happen. Why?

______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________(15 points)

15.

1. A navigator who conceived, but was unable to complete, the first trip around the world. This journey proved the existence of a single World Ocean and the sphericity of the Earth. ___________________

2. Russian navigator, admiral, honorary member of the St. Petersburg Academy of Sciences, founding member of the Russian Geographical Society, head of the first Russian round-the-world expedition on the ships “Nadezhda” and “Neva”, author of the “Atlas of the South Sea” _____________________________________________

3. Italian traveler, explorer of China and India. The first to describe Asia in more detail was ______________________________

4. Russian navigator, discoverer of Antarctica. Commanded the sloop "Vostok" ______________________________

5. English navigator. He led three expeditions around the world, discovered many islands in the Pacific Ocean, found out the island position of New Zealand, discovered the Great Barrier Reef, the east coast of Australia, the Hawaiian Islands ___________________________

(for each correct answer 2 points)

Answers to the tasks of the Olympiad (school tour).

7th grade

1. 34 S 19E _

2. 1 cm 300 km _

1) Nile

2) Chomolungma

3) -Amazonian

4) -Angel

5-Baikal

6) -Antarctica

7) -Drake

8) -Caspian

9) -Australia

10) Red sea ( 2 points for each correct answer)

1) Laurasia - an ancient continent, 2) Trade wind - wind from 30 latitudes to the equator

3) Meridian - line, conn. north and south pole

4) Azimuth - the angle between the direction north and the direction to the object (for each correct answer 2 b)

5. North and south pole(5 points)

6. Amazon river(2 points)

7. Chomolungma (2 points)

1) tsunami, 2) waterfall, 3) iceberg(for each correct answer 2 points)

9. highest amount of precipitation (5 points)

10. The daytime breeze blows from the sea to the land. And not vice versa(15 points)

11. Correct geographical errors

Island Madagascar, Arabian sea, Ladoga lake, mountains Himalayas, river Amazon, Red sea ,

island Greenland (for each correct answer 2 points)

12. _polar explorer(10 points)

13. Indicate the purpose of the devices and instruments listed in the table. Fill in the cells in the table.

Device name	Purpose of the device
	to determine the height difference between points
Hygrometer	To determine air humidity
Luxmeter	To measure illumination
Bathometer	for taking a water sample from a given depth of a natural reservoir in order to study its physical and chemical properties, as well as the organic and inorganic inclusions it contains
Seismograph	for detecting and recording all types of seismic waves

(for each correct answer 2 points)

14. firstly, because the air heated near the earth quickly cools when moving away from it, and secondly, because in the upper layers of the atmosphere the air is more rarefied than near the earth. The lower the air density, the less heat is transferred. Figuratively, this can be explained as follows: the higher the air density, the more molecules there are per unit volume, the faster they move and the more often they collide, and such collisions, like any friction, cause the release of heat. Thirdly, the sun's rays on the surface of mountain slopes always fall not vertically, as on the earth's surface, but at an angle. And besides, the mountains are prevented from warming up by the dense snow caps with which they are covered - white snow simply reflects the sun's rays. (15 points)

17. Determine which of the travelers (geographers) we are talking about?

1. Magellan

2. Krusenstern

3. Marco Polo

4. Bellingshausen

5. Cook

1. Vasco da Gama

The rays of the Sun, as already mentioned, when passing through the atmosphere, experience some changes and give off some of the heat to the atmosphere. But this heat, distributed throughout the entire atmosphere, has a very small effect in terms of heating. The temperature conditions of the lower layers of the atmosphere are mainly influenced by the temperature of the earth's surface. The lower layers of the atmosphere are heated from the heated surface of land and water, and cooled from the cooled surface. Thus, the main source of heating and cooling of the lower layers of the atmosphere is precisely earth's surface. However, the term “earth’s surface” in this case (i.e., when considering processes occurring in the atmosphere) is sometimes more convenient to replace with the term underlying surface. With the term earth's surface, we most often associate the idea of ​​the shape of the surface, taking into account land and sea, while the term underlying surface denotes the earth's surface with all its inherent properties that are important for the atmosphere (shape, nature of rocks, color, temperature, humidity, vegetation cover and etc.).

The circumstances we have noted force us, first of all, to focus our attention on the temperature conditions of the earth's surface, or, more precisely, the underlying surface.

Heat balance on the underlying surface. The temperature of the underlying surface is determined by the ratio of heat inflow and outflow. The incoming and outgoing balance of heat on the earth's surface during the daytime consists of the following quantities: incoming - heat coming from direct and diffuse solar radiation; consumption - a) reflection of part of solar radiation from the earth's surface, b) evaporation, c) earth radiation, d) heat transfer to adjacent layers of air, e) heat transfer deep into the soil.

At night, the components of the incoming and outgoing heat balance on the underlying surface change. There is no solar radiation at night; heat can come from the air (if its temperature is higher than the temperature of the earth's surface) and from the lower layers of the soil. Instead of evaporation, there may be condensation of water vapor on the soil surface; The heat generated during this process is absorbed by the earth's surface.

If the heat balance is positive (heat inflow is greater than heat outflow), then the temperature of the underlying surface increases; if the balance is negative (income is less than consumption), then the temperature decreases.

The heating conditions of the land surface and the water surface are very different. Let us first dwell on the conditions for heating sushi.

Heating the sushi. The land surface is not uniform. In some places there are vast expanses of steppes, meadows and arable lands, in others there are forests and swamps, and in others there are deserts almost devoid of vegetation. It is clear that the conditions for heating the earth's surface in each of the cases we have presented are far from the same. Most easily they will be where the earth's surface is not covered with vegetation. We will focus on these simplest cases first.

To measure the temperature of the surface layer of soil, a conventional mercury thermometer is used. The thermometer is placed in an unshaded place, but so that the lower half of the reservoir with mercury is in the thickness of the soil. If the soil is covered with grass, then the grass must be cut (otherwise the area of ​​soil being examined will be shaded). However, it must be said that this method cannot be considered completely accurate. To obtain more accurate data, electric thermometers are used.

Measuring soil temperature at a depth of 20-40 cm produce soil mercury thermometers. To measure deeper layers (from 0.1 to 3, and sometimes more meters), so-called exhaust thermometers. These are essentially the same mercury thermometers, but only placed in an ebonite tube, which is buried in the ground to the required depth (Fig. 34).

During the daytime, especially in summer, the soil surface becomes very hot and cools down very much during the night. Typically, the maximum temperature occurs around 13:00, and the minimum occurs before sunrise. The difference between the highest and lowest temperatures is called amplitude daily fluctuations. In summer, the amplitude is much greater than in winter. So, for example, for Tbilisi in July it reaches 30°, and in January 10°. In the annual variation of soil surface temperature, the maximum is usually observed in July and the minimum in January. From the top heated layer of soil, the heat is partly transferred to the air, and partly to layers located deeper. At night the process is reversed. The depth to which daily temperature fluctuations penetrate depends on the thermal conductivity of the soil. But in general it is small and ranges from approximately 70 to 100 cm. In this case, the daily amplitude decreases very quickly with depth. So, if on the soil surface the daily amplitude is 16°, then at a depth of 12 cm it is already only 8°, at a depth of 24 cm - 4°, and at a depth of 48 cm-1°. From the above it is clear that the heat absorbed by the soil accumulates mainly in its upper layer, the thickness of which is measured in centimeters. But this top layer of soil is precisely the main source of heat on which temperature depends

layer of air adjacent to the soil.

Annual fluctuations penetrate much deeper. In temperate latitudes, where the annual amplitude is especially large, temperature fluctuations die out at a depth of 20-30 m.

The transfer of temperatures into the Earth occurs rather slowly. On average, for every meter of depth, temperature fluctuations lag by 20-30 days. Thus, the highest temperatures observed on the Earth's surface in July are at a depth of 5 m will be in December or January, and the lowest in July.

Influence of vegetation and snow cover. Vegetation cover shades the earth's surface and thereby reduces the flow of heat to the soil. At night, on the contrary, the vegetation cover protects the soil from radiation emission. In addition, the vegetation cover evaporates water, which also consumes part of the radiant energy of the Sun. As a result, soils covered with vegetation heat up less during the day. This is especially noticeable in the forest, where in summer the soil is much colder than in the field.

An even greater influence is exerted by snow cover, which, due to its low thermal conductivity, protects the soil from excessive winter cooling. From observations made in Lesnoy (near Leningrad), it turned out that soil devoid of snow cover is on average 7° colder in February than soil covered with snow (data derived from 15 years of observations). In some years in winter the temperature difference reached 20-30°. From the same observations, it turned out that soils devoid of snow cover froze to 1.35 m depth, while under snow cover freezing is no deeper than 40 cm.

Soil freezing and permafrost . The question of the depth of soil freezing is of great practical importance. Suffice it to recall the construction of water pipelines, reservoirs and other similar structures. In the central zone of the European part of the USSR, the freezing depth ranges from 1 to 1.5 m, in the southern regions - from 40 to 50 cm. In Eastern Siberia, where winters are colder and snow cover is very small, the freezing depth reaches several meters. Under these conditions, during the summer period the soil has time to thaw only from the surface, and deeper remains a permanently frozen horizon, known as permafrost. The area where permafrost occurs is huge. In the USSR (mainly in Siberia) it occupies over 9 million. km 2. Warming of the water surface. The heat capacity of water is twice the heat capacity of the rocks that make up the land. This means that under the same conditions, over a certain period of time, the surface of the land will have time to heat up twice as much as the surface of the water. In addition, water evaporates when heated, which also costs a lot of money.

amount of thermal energy. And finally, it is necessary to note another very important reason that slows down heating: this is the mixing of the upper layers of water due to waves and convection currents (up to a depth of 100 and even 200 m).

From all that has been said, it is clear that the surface of the water heats up much more slowly than the surface of the land. As a result, the daily and annual amplitudes of sea surface temperatures are many times smaller than the daily and annual amplitudes of the land surface.

However, due to its greater heat capacity and deeper heating, the water surface accumulates much more heat than the land surface. As a result, the average surface temperature of the oceans, according to calculations, exceeds the average air temperature of the entire globe by 3°. From all that has been said, it is clear that the conditions for heating the air above the sea surface are significantly different from the conditions on land. Briefly, these differences can be described as follows:

1) in areas with a large diurnal amplitude (tropical zone), at night the sea temperature is higher than the land temperature, and during the day the opposite phenomenon occurs;

2) in areas with a large annual amplitude (temperate and polar zones), the sea surface is warmer in autumn and winter, and colder in summer and spring, than the land surface;

3) the sea surface receives less heat than the land surface, but retains it longer and spends it more evenly. As a result, the sea surface is on average warmer than the land surface.

Methods and instruments for measuring air temperature. Temperatureair is usually measured using mercury thermometers. In cold countries, where the air temperature drops below the freezing point of mercury (mercury freezes at - 39°), alcohol thermometers are used.

When measuring air temperature, thermometers must be placed V protection to protect them from direct solar radiation and from terrestrial radiation. In the USSR, for these purposes we use a psychrometric (louvered) wooden booth (Fig. 35), which is installed at a height of 2 m from the soil surface. All four walls of this booth are made of a double row of inclined slats in the form of blinds, the roof is double, the bottom consists of three boards located at different heights. This arrangement of the psychrometric booth protects thermometers from direct solar radiation and at the same time allows air to freely penetrate into it. To reduce the heating of the booth, it is painted white. The doors of the booth open to the north so that the sun's rays do not fall on the thermometers when readings.

In meteorology, thermometers of various designs and purposes are known. Of these, the most common are: psychrometric thermometer, sling thermometer, maximum and minimum thermometers.

is the main one currently accepted for determining air temperature during urgent observation hours. This is a mercury thermometer (Fig. 36) with an insert scale, the division value of which is 0°.2. When determining air temperature with a psychrometric thermometer, it is installed in a vertical position. In areas with low air temperatures, in addition to a mercury psychrometric thermometer, a similar alcohol thermometer is used at temperatures below 20°.

In expeditionary conditions, they are used to determine air temperature. sling thermometer(Fig. 37). This instrument is a small mercury thermometer with a stick type scale; divisions on the scale are marked at 0°.5. OK, a cord is tied to the upper end of the thermometer, with the help of which, when measuring temperature, the thermometer is quickly rotated above the head so that its mercury reservoir comes into contact with large masses of air and is less heated by solar radiation. After rotating the sling thermometer for 1-2 minutes. The temperature is measured, and the device must be placed in the shade so that it is not exposed to direct solar radiation.

serves to determine the highest temperature observed during any elapsed period of time. Unlike conventional mercury thermometers, the maximum thermometer (Fig. 38) has a glass pin soldered into the bottom of the mercury reservoir, the upper end of which slightly enters the capillary vessel, greatly narrowing its opening. When the air temperature rises, the mercury in the tank expands and rushes into the capillary vessel. Its narrowed opening is not a big obstacle. The column of mercury in the capillary vessel will rise as the air temperature rises. When the temperature begins to decrease, the mercury in the reservoir will begin to shrink and will break away from the mercury column in the capillary vessel due to the presence of a glass pin. After each reading, shake the thermometer, as is done with a medical thermometer. When making observations, the maximum thermometer is placed horizontally, since the capillary of this thermometer is relatively wide and the mercury in it in an inclined position can move regardless of the temperature. The maximum thermometer scale division value is 0°.5.

To determine the lowest temperature over a certain period of time, it is used minimal thermometer(Fig. 39). The minimum thermometer is an alcohol thermometer. Its scale is divided into 0°.5. When taking measurements, the minimum thermometer, as well as the maximum, is installed in a horizontal position. In the capillary vessel of a minimum thermometer, a small pin made of dark glass and with thickened ends is placed inside the alcohol. As the temperature decreases, the column of alcohol shortens and the surface film of alcohol will move the pin

tick to the tank. If the temperature then begins to rise, the column of alcohol will lengthen, and the pin will remain in place, fixing the minimum temperature.

To continuously record changes in air temperature during the day, recorders - thermographs - are used.

Currently, two types of thermographs are used in meteorology: bimetallic and manometric. The most widely used thermometers are those with a bimetallic receiver.

(Fig. 40) has a bimetallic (double) plate as a temperature receiver. This plate consists of two thin dissimilar metal plates soldered together, each with a different temperature coefficient of expansion. One end of the bimetallic strip is fixedly fixed in the device, the other is free. When the air temperature changes, the metal plates will deform differently and, therefore, the free end of the bimetallic plate will bend in one direction or another. And these movements of the bimetallic plate are transmitted through a system of levers to the arrow to which the pen is attached. The pen, moving up and down, draws a curved line of temperature change on a paper tape wound on a drum rotating around an axis using a clock mechanism.

U manometric thermographs The temperature receiver is a curved brass tube filled with liquid or gas. Otherwise they are similar to bimetallic thermographs. As the temperature increases, the volume of the liquid (gas) increases, and as the temperature decreases, it decreases. A change in the volume of liquid (gas) deforms the walls of the tube, and this, in turn, is transmitted through a system of levers to the arrow with the feather.

Vertical distribution of temperatures in the atmosphere. Heating of the atmosphere, as we have already said, occurs in two main ways. The first is the direct absorption of solar and terrestrial radiation, the second is the transfer of heat from the heated earth's surface. The first path was sufficiently covered in the chapter on solar radiation. Let's take the second path.

Heat is transferred from the earth's surface to the upper layers of the atmosphere in three ways: molecular thermal conductivity, thermal convection and through turbulent air mixing. The molecular thermal conductivity of air is very small, so this method of heating the atmosphere does not play a big role. The greatest importance in this regard is thermal convection and turbulence in the atmosphere.

The lower layers of air, heating up, expand, reduce their density and rise upward. The resulting vertical (convection) currents transfer heat to the upper layers of the atmosphere. However, this transfer (convection) is not easy. Rising warm air, entering conditions of lower atmospheric pressure, expands. The expansion process requires energy, causing the air to cool. It is known from physics that the temperature of the rising air mass when rising for every 100 m decreases by approximately 1°.

However, the conclusion we have given applies only to dry or moist but unsaturated air. When saturated air cools, it condenses water vapor; in this case, heat is released (latent heat of vaporization), and this heat increases the air temperature. As a result, when air saturated with moisture rises for every 100 m the temperature drops not by 1°, but by approximately 0°.6.

When air descends, the reverse process occurs. Here for every 100 m lowering, the air temperature rises by 1°. The degree of air humidity in this case does not play a role, because as the temperature rises, the air moves away from saturation.

If we take into account that air humidity is subject to strong fluctuations, then the complexity of the conditions for heating the lower layers of the atmosphere becomes obvious. In general, as already mentioned in its place, in the troposphere there is a gradual decrease in air temperature with height. And at the upper boundary of the troposphere, the air temperature is 60-65° lower than the air temperature at the Earth's surface.

The daily variation of air temperature amplitude decreases quite quickly with height. Daily amplitude at an altitude of 2000 m expressed only in tenths of a degree. As for annual fluctuations, they are much greater. Observations have shown that they decrease to a height of 3 km. Above 3 km there is an increase that increases to 7-8 km height, and then decreases again to approximately 15 km.

Temperature inversion. There are cases when the lower ground layers of air may be colder than those lying above. This phenomenon is called temperature inversion; A sharp temperature inversion is expressed where there is no wind during cold periods. In countries with long, cold winters, temperature inversions are common in winter. It is especially pronounced in Eastern Siberia, where, due to the prevailing high pressure and calmness, the temperature of the supercooled air at the bottom of the valleys is extremely low. As an example, we can point to the Verkhoyansk or Oymyakon depressions, where the air temperature drops to -60 and even -70°, while on the slopes of the surrounding mountains it is much higher.

The origin of temperature inversions varies. They can be formed as a result of the flow of cooled air from the slopes of mountains into closed basins, due to strong radiation of the earth's surface (radiative inversion), during the advection of warm air, usually in early spring, over the snow cover (snow inversion), when cold air masses attack warm ones ( frontal inversion), due to turbulent mixing of air (turbulence inversion), with the adiabatic lowering of air masses that have a stable stratification (compression inversion).

Frost. During the transitional seasons of the year in spring and autumn, when the air temperature is above 0°, frosts are often observed on the soil surface in the morning hours. Based on their origin, frosts are divided into two types: radiation and advection.

Radiation freezes are formed as a result of cooling of the underlying surface at night due to terrestrial radiation or due to the flow of cold air with a temperature below 0° from the slopes of elevations into depressions. The occurrence of radiation frosts is facilitated by the absence of clouds at night, low air humidity and windless weather.

Advective frost arise as a result of the invasion of a particular territory by cold air masses (Arctic or continental polar masses). In these cases, frosts are more persistent and cover large areas.

Frosts, especially late spring ones, often cause great harm to agriculture, since often the low temperatures observed during frosts destroy agricultural plants. Since the main cause of frosts is the cooling of the underlying surface by the earth's radiation, the fight against them goes along the line of artificially reducing the radiation of the earth's surface. The amount of such radiation can be reduced by creating smoke (by burning straw, manure, pine needles and other combustible material), artificially humidifying the air and creating fog. To protect valuable crops from frost, they sometimes use direct heating of plants in various ways or build canopies from canvas, straw and reed mats and other materials; Such canopies reduce the cooling of the earth's surface and prevent the occurrence of frost.

Daily cycle air temperature. At night, the Earth's surface radiates heat all the time and gradually cools. Along with the earth's surface, the lower layer of air also cools. In winter, the moment of greatest cooling usually occurs shortly before sunrise. When the Sun rises, the rays fall on the earth's surface at very sharp angles and hardly heat it, especially since the Earth continues to radiate heat into space. As the Sun rises higher and higher, the angle of incidence of the rays increases, and the arrival of solar heat becomes greater than the expenditure of heat emitted by the Earth. From this moment on, the temperature of the Earth's surface, and then the air temperature, begins to rise. And the higher the Sun rises, the steeper the rays fall and the higher the temperature of the earth's surface and air rises.

After noon, the heat influx from the Sun begins to decrease, but the air temperature continues to rise, because the loss of solar radiation is compensated by the emission of heat from the earth's surface. However, this cannot continue for long, and a moment comes when terrestrial radiation can no longer cover the loss of solar radiation. This moment in our latitudes occurs around two in the winter, and around three in the summer in the afternoon. After this point, a gradual drop in temperature begins, until sunrise the next morning. This daily temperature variation is very clearly visible in the diagram (Fig. 41).

In different zones of the globe, the daily variation of air temperatures is very different. At sea, as already mentioned, the daily amplitude is very small. In desert countries, where the soils are not covered with vegetation, during the day the Earth's surface heats up to 60-80°, and at night it cools down to 0°; daily amplitudes reach 60 degrees or more.

Annual variation of air temperatures. The earth's surface in the northern hemisphere receives the greatest amount of solar heat at the end of June. In July, solar radiation decreases, but this decrease is compensated by the still quite strong solar radiation and radiation from the highly heated earth's surface. As a result, the air temperature in July is higher than in June. On the seashore and on the islands, the highest air temperatures are observed not in July, but in August. This is explained

the fact that the water surface takes longer to heat up and consumes its heat more slowly. Much the same thing happens in the winter months. The earth's surface receives the least amount of solar heat at the end of December, and the lowest air temperatures are observed in January, when the increasing influx of solar heat cannot yet cover the heat consumption resulting from the earth's radiation. Thus, the warmest month for sushi is July, and the coldest is January.

The annual variation of air temperature for different parts of the globe is very different (Fig. 42). First of all, it is, of course, determined by the latitude of the place. Depending on latitude, there are four main types of annual temperature variations.

1. Equatorial type. It has a very small amplitude. For the interior of the continents it is about 7°, for the coasts about 3°, on the oceans 1°. The warmest periods coincide with the zenithal position of the Sun at the equator (during the spring and autumn equinoxes), and the coldest seasons coincide with the summer and winter solstices. Thus, during the year there are two warm and two cold periods, the difference between which is very small.

2. Tropical type. The highest position of the Sun is observed during the summer solstice, the lowest during the winter solstice. As a result, during the year there is one period of maximum temperatures and one period of minimum temperatures. The amplitude is also small: on the coast - about 5-6°, and inland - about 20°.

3. Temperate zone type. Here the highest temperatures are in July and the lowest in January (in the southern hemisphere the opposite). In addition to these two extreme periods of summer and winter, there are two more transitional periods: spring and autumn. The annual amplitudes are very large: in coastal countries 8°, within continents up to 40°.

4. Polar type. It is characterized by very long winters and short summers. In winter, great cold sets in inside the continents. The amplitude near the coast is about 20-25°, while inside the continent it is more than 60°. As an example of exceptionally large winter colds and annual amplitudes, one can cite Verkhoyansk, where the absolute minimum air temperature was recorded at -69°.8 and where the average temperature in January is -51°, and in July -+-.15°; the absolute maximum reaches +33°.7.

Looking closely at the temperature conditions of each of the types of annual temperature variations given here, we must first of all note the striking difference between the temperatures of sea coasts and the interior parts of continents. This difference has long made it possible to distinguish two types of climates: nautical And continental. Within the same latitude, land is warmer in summer and colder in winter than the sea. For example, off the coast of Brittany the January temperature is 8°, in southern Germany at the same latitude it is 0°, and in the Lower Volga region it is -8°. The differences are even greater when we compare the temperatures of oceanic stations with those of continental stations. Thus, in the Faroe Islands (Grohavy station), the coldest month (March) has an average temperature of +3°, and the warmest (July) is +11°. In Yakutsk, located at the same latitudes, the average January temperature is 43°, and the average July temperature is +19°.

Isotherms. Various heating conditions due to the latitude of the place and the influence of the sea create a very complex picture of the distribution of temperatures over the earth's surface. To visualize this location on a geographic map, places with similar temperatures are connected by lines known as isotherm Due to the fact that the altitude of stations above sea level is different, and the altitude has a significant influence on temperatures, it is customary to reduce the temperature values ​​​​obtained at weather stations to sea level. Isotherms of average monthly and average annual temperatures are usually plotted on maps.

January and July isotherms. The brightest and most characteristic picture of temperature distribution is provided by maps of January and July isotherms (Fig. 43, 44).

Let's first look at the January isotherm map. What is most striking here is the warming influence of the Atlantic Ocean, and, in particular, the warm Gulf Stream on Europe, as well as the cooling influence of wide areas of land in the temperate and polar countries of the northern hemisphere. This influence is especially great in Asia, where closed isotherms of - 40, - 44 and - 48 ° surround the cold pole. The relatively small deviation of isotherms from the direction of parallels in the moderately cold zone of the southern hemisphere is striking, which is a consequence of the predominance of vast areas of water there. The map of July isotherms sharply reveals the higher temperature of the continents compared to the oceans at the same latitudes.

Annual isotherms and thermal zones of the Earth. To get an idea of ​​the distribution of heat over the earth's surface on average over a whole year, use maps of annual isotherms (Fig. 45). These maps show that the warmest places do not coincide with the equator.

The mathematical boundary between the hot and temperate zones is the tropics. The actual boundary, which is usually drawn along the annual isotherm of 20°, noticeably does not coincide with the tropics. On land, it most often moves towards the poles, and in the oceans, especially under the influence of cold currents, towards the equator.

It is much more difficult to draw the line between cold and temperate zones. For this, not the annual, but the July isotherm of 10° is best suited. Forest vegetation does not extend north of this border. On land, tundra dominates everywhere. This border does not coincide with the Arctic Circle. Apparently, the coldest points on the globe also do not coincide with the mathematical poles. The same maps of annual isotherms allow us to notice that the northern hemisphere at all latitudes is somewhat warmer than the southern one and that the western shores of the continents in the middle and high latitudes are much warmer than the eastern ones.

Izanomaly. Tracing the course of January and July isotherms on the map, you can easily notice that temperature conditions at the same latitudes of the globe are different. Moreover, some points have a lower temperature than the average temperature for a given parallel, while others, on the contrary, have a higher temperature. The deviation of the air temperature of any point from the average temperature of the parallel on which this point is located is called temperature anomaly.

Anomalies can be positive or negative, depending on whether the temperature of a given point is greater or less than the average temperature of the parallel. If the temperature of a point is higher than the average temperature for a given parallel, then the anomaly is considered positive,

with the opposite temperature ratio, the anomaly is negative.

Lines on a map connecting places on the earth's surface with the same temperature anomaly values ​​are called temperature anomalies(Fig. 46 and 47). From the map of January anomalies it is clear that in this month the continents of Asia and North America have air temperatures below the average January temperature for these latitudes. Atlantic and

The Pacific Oceans, as well as Europe, on the contrary, have a positive temperature anomaly. This distribution of temperature anomalies is explained by the fact that in winter land cools faster than water areas.

In July, a positive anomaly is observed on the continents. There is a negative temperature anomaly over the oceans of the northern hemisphere at this time.

- Source-

Polovinkin, A.A. Fundamentals of general geoscience/ A.A. Polovinkin. - M.: State educational and pedagogical publishing house of the Ministry of Education of the RSFSR, 1958. - 482 p.

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Our planet has a spherical shape, so the sun's rays fall on the earth's surface at different angles and heat it unevenly. At the equator, where the sun's rays fall vertically, the Earth's surface heats up more. The closer to the poles, the smaller the angle of incidence of the sun's rays and the less the surface heats up.

In the polar regions, the rays seem to glide across the planet and hardly heat it up. Moreover, having traveled a long way in the atmosphere,

The sun's rays are greatly scattered and bring less heat to the Earth. The ground layer of air is heated by the underlying surface, therefore, air temperature decreases from the equator to the poles.

It is known that the earth's axis is inclined to the orbital plane along which the earth rotates around the sun, therefore the Northern and Southern hemispheres heat up unevenly depending on the seasons, which also affects the air temperature.

At any point on Earth, the air temperature changes throughout the day and throughout the year. It depends on how high the Sun is above the horizon and on the length of the day. During the day, the highest temperature is observed at 14-15 hours, and the lowest is shortly after sunrise.

The change in temperature from the equator to the poles depends not only on the geographical latitude of the place, but also on the planetary transfer of heat from low to high latitudes, on the distribution of continents and oceans on the surface of the planet, which

They are heated differently by the Sun and give off heat differently, as well as depending on the position of mountain ranges and ocean currents. For example, the Northern half

Sharia is warmer than the South, because in the southern polar region there is a large continent, Antarctica, covered with an ice shell.

On maps, air temperature above the earth's surface is shown using isotherms - lines connecting points with the same temperature. Isotherms are close to parallel only where they cross oceans, and bend strongly over continents.

The intensity of heating of the Earth's surface depending on the incidence of solar rays

Areas where the sun's rays greatly heat the Earth's surface

Areas where the sun's rays heat the Earth's surface less

Areas where the sun's rays barely heat the Earth

Based on isotherm maps, heat zones are identified on the planet. The hot zone is located in equatorial latitudes between the average annual isotherms of +20 °C. Temperate zones are located north and south of the hot zone and are limited by isotherms of + 10 ° C. Two cold belts lie between the isotherms of + 10 ° C and 0 ° C, and there are frost belts at the North and South Poles.

With altitude, the air temperature decreases by an average of 6 °C with an increase of 1 km.

In autumn and spring, frosts often occur - the air temperature drops below 0 °C at night, while average daily temperatures remain above zero. Frosts most often occur on clear, quiet nights, when fairly cold air masses enter the area, for example, from the Arctic. During frosts, the air cools significantly near the earth's surface, warm air appears above the cold layer, and temperature inversion- temperature increases with altitude. It is often observed in polar regions, where the earth's surface cools greatly at night.

Night frosts

Thermal zones of the Earth

In the atmosphere, water exists in three states of aggregation - gaseous (water vapor), liquid (raindrops) and solid (crystals of snow and ice). Compared to the entire mass of water on the planet, there is very little of it in the atmosphere - about 0.001%, but its importance is enormous. Clouds and water vapor absorb and reflect excess solar radiation, and also regulate its entry to Earth. At the same time, they block oncoming thermal radiation coming from the Earth's surface into interplanetary space. The water content in the atmosphere determines the weather and climate of the area. It determines what the temperature will be, whether clouds will form over a given area, whether rain will come from the clouds, whether dew will fall.

Three states of water

Water vapor continuously enters the atmosphere, evaporating from the surface of reservoirs and soil. Plants also secrete it - this process is called transpiration. Water molecules are strongly attracted to each other due to the forces of intermolecular attraction, and the Sun has to spend a lot of energy to separate them and turn them into steam. It takes 537 calories of solar energy to create one gram of water vapor. There is not a single substance whose specific heat of evaporation is greater than that of water. It is estimated that in one minute the Sun evaporates a billion tons of water on Earth. Water vapor rises into the atmosphere along with

rising air currents. As it cools, it condenses, clouds form, and at the same time a huge amount of energy is released, which the water vapor returns to the atmosphere. It is this energy that makes the winds blow, carries hundreds of billions of tons of water in the clouds and moistens the surface of the Earth with rain.

Evaporation consists of water molecules breaking off from the water surface or moist soil, moving into the air and turning into water vapor molecules. In the air they move independently and are carried by the wind, and their place is taken by new evaporated molecules. Simultaneously with evaporation from the surface of soil and reservoirs, the reverse process also occurs - water molecules from the air pass into water or soil. Air in which the number of evaporating water vapor molecules is equal to the number of returning molecules is called saturated, and the process itself is called saturation. The higher the air temperature, the more water vapor it can contain. So, in 1 m3 of air

AEROPLANKTON

American microbiologist Parker found that the air contains a large amount of organic substances and many microorganisms, including algae, some of which are in an active state. The temporary residence of these organisms can be, for example, cumulus clouds. Acceptable temperature, water, microelements, radiant energy for life processes - all this creates favorable conditions for photosynthesis, metabolism and cell growth. According to Parker, “clouds are living ecological systems” that provide multicellular microorganisms with the ability to live and reproduce.

ha at a temperature of +20 °C can contain 17 g of water vapor, and at a temperature of -20 °C only 1 g of water vapor.

With the slightest drop in temperature, air saturated with water vapor is no longer able to contain moisture and precipitation falls out of it, for example, fog forms or dew falls. At the same time, water vapor condenses - passes from a gaseous state to a liquid one. The temperature at which water vapor in the air saturates it and condensation begins is called dew point.

Air humidity is characterized by several indicators.

Absolute air humidity - the amount of water vapor contained in the air, expressed in grams per cubic meter, sometimes also called pressure or density of water vapor. At a temperature of 0 °C, the absolute humidity of saturated air is 4.9 g/m 3 . At equatorial latitudes, absolute air humidity is about 30 g/m 3 , and in the circumpolar

areas - 0.1 g/m3.

Percentage of the amount of water vapor contained in the air to the amount of water vapor that can be contained in the air

at a given temperature is called

relative

air humidity. It shows the degree of saturation of air with water vapor. If, for example, the relative humidity is 50%, this means that the air contains only half the amount of water vapor that it could hold at that temperature. In equatorial latitudes and polar regions, relative air humidity is always high. At the equator, with heavy clouds, the air temperature is not too high, and the moisture content in it is significant. In high latitudes, the air moisture content is low, but the temperature is not high, especially in winter. Very low relative humidity is typical for tropical deserts - 50% and below.

There are different types of clouds. On a gloomy rainy day, their dense gray layers hang low above the Earth, preventing the sun's rays from breaking through. In the summer, fancy white “lambs” run one after another across the blue sky, and sometimes high, high, where an airplane flies like a silver star, you can see snow-white transparent “feathers” and “claws”. All these are clouds - an accumulation in the atmosphere of water droplets, ice crystals, and more often than not, both at the same time.

Despite all the variety of shapes and types of clouds, the reason for their formation is one. A cloud forms because air heated near the Earth's surface rises and gradually cools. At a certain height, tiny droplets of water begin to condense from it (from the Latin condensatio - thickening), water vapor passes from a gaseous state to a liquid one. This happens because cold air contains less water vapor than warm air. To begin the condensation process, it is necessary that the air

condensation nuclei were present - tiny solid particles (dust, salts and other substances) to which water molecules can stick.

Most clouds form in the troposphere, but occasionally they occur in higher atmospheric layers. Tropospheric clouds are conventionally divided into three tiers: lower - up to 2 km, middle - from 2 to 8 km and upper tier - from 8 to 18 km. By shape, cirrus, stratus and cumulus clouds are distinguished, but their appearance and structure are so diverse that meteorologists distinguish types, types and individual varieties of clouds. Each cloud shape corresponds specifically

approved Latin name. For example, altocumulus lenticular clouds

called Altocumulus Lenticularis. The lower tier is characterized by stratus, stratocumulus and stratocumulus.

rain clouds. They are almost all

where they are impenetrable to sunlight and give continuous and prolonged precipitation.

IN in the lower tier, cumulus and cumulus can form

rain clouds.

Diagram of cumulus cloud formation

They often take the form of towers or domes, growing up to 5-8 km and higher. The lower part of these clouds is gray and sometimes blue-black and consists of water, and the upper part is bright white and consists of ice crystals. Cumulus clouds are associated with showers, thunderstorms and hail.

The middle tier is characterized by altostratus and altocumulus clouds, consisting of a mixture of droplets, ice crystals and snowflakes.

Cirrus, cirrostratus and cirrocumulus clouds form in the upper tier. The Moon and Sun are clearly visible through these icy translucent clouds. Cirrus clouds do not carry precipitation, but are often harbingers of changing weather.

Occasionally, at an altitude of 20-25 km, special, very light pearly clouds, consisting of supercooled water droplets. And even higher - at an altitude of 75-90 km - noctilucent clouds consisting of ice crystals. During the day these clouds are impossible to see, but at night they are illuminated by the Sun below the horizon, and they shine faintly.

The extent to which the sky is covered by clouds is called cloud cover. It is measured in points on a ten-point scale (totally cloudy - 10 points) or as a percentage. During the day, clouds protect the surface of the planet from excessive heating by the sun's rays, and at night they prevent cooling. Clouds cover almost half the globe, they are more numerous in areas of low pressure (where air rises) and are especially numerous over the oceans, where the air contains more moisture than over the continents.

Showers and drizzles, fluffy light snow

And heavy snowfalls, hail and dew drops, thick fogs and frost crystals on tree branches - that’s what precipitation is. This is water in a solid or liquid state that falls from clouds or is deposited on the surface of the Earth, as well as on various objects directly from the air as a result of condensation of water vapor.

Clouds consist of tiny droplets with a diameter of 0.05 to 0.1 mm. They are so small that they can float freely in the air. As the temperature in the cloud drops, more droplets form

And more, they merge, become heavier and finally fall to Earth in the form rain Sometimes temperature

V the cloud falls so low that the drops drain

when they melt, they form ice crystals. They fly down, fall into warmer layers of air, melt and also rain.

In summer, rain usually falls, consisting of large drops, because at this time the earth's surface is intensely heated and moisture-saturated air rapidly rises. In spring and autumn, it rains more often, and sometimes tiny droplets of water hang in the air - drizzle.

It happens that in the summer strong rising air currents lift moist warm air to a great height, and then the water drops freeze. As they fall, they collide with other drops, which stick to them and also

are freezing. Formed hailstones

rise upwards

moving air currents, gradually several layers of ice grow on them, they become heavier and finally fall to the ground. Having split a hailstone, you can see how layers of ice have grown on its core, like the growth rings of a tree.

Precipitation in the form of snow occurs when the cloud is in the air at a temperature below 0 ° C. Snowflakes are complex ice crystals, six-rayed stars of various shapes that are not repeated.

they eat each other. As they fall, they combine to form snow flakes.

During the day in summer, the sun warms the surface well

soil, the ground layer of air also heats up

Ha. In the evening the earth and the air above it

they poke. Water vapor, which was contained in the warm air, can no longer be retained in it, condenses and falls in the form of dew drops on the earth's surface, on grass, and tree leaves. As soon as the Sun heats the earth in the morning, the surface layer of air will also heat up and the dew will evaporate.

Frost is a thin layer of ice crystals of various shapes that form under the same conditions as dew, but at negative temperatures. Frost appears on quiet, clear nights on the surface of the Earth, on grass and various objects whose temperature is lower than the air temperature. In this case, water vapor turns into ice crystals, bypassing the liquid state. This process is called sublimation.

In calm, frosty weather, when fog forms, tiny drops of water settle in the form of ice crystals on tree branches, thin fences and wires. So it appears from -

frost.

In spring, during thaws, precipitation sometimes falls in the form of rain and snow at the same time

Precipitation on our planet is distributed extremely unevenly. In some areas, it rains every day and so much moisture reaches the surface of the Earth that rivers remain full all year round, and tropical forests rise in tiers, blocking sunlight. But you can also find places on the planet where for several years in a row not a drop of rain falls from the sky, the dried-up beds of temporary water streams crack under the rays of the scorching Sun, and meager plants can only reach deep layers of underground water thanks to their long roots. What is the reason for such injustice?

Precipitation distribution on the globe depends on how many clouds containing moisture form over a given area or how many of them the wind can bring. Air temperature is very important, because intense evaporation of moisture occurs at high temperatures. The moisture evaporates, rises and clouds form at a certain altitude.

Air temperature decreases from the equator to the poles, therefore, the amount of precipitation is maximum at equatorial latitudes and decreases towards the poles. However, on land, the distribution of precipitation depends on a number of additional factors.

There is a lot of precipitation over coastal areas, and as you move away from the oceans, their amount decreases. More precipitation on the

More precipitation falls on the windward slopes of the mountains than on the leeward ones

windy slopes of mountain ranges and much less on leeward ones. For example, on the Atlantic coast of Norway, Bergen receives 1,730 mm of precipitation per year, while Oslo (beyond the ridge) receives only 560 mm. Low mountains also affect the distribution of precipitation -

Over areas where warm currents flow, more precipitation falls, and over areas where cold currents flow nearby, less precipitation falls.

On the western slope of the Urals, in Ufa, an average of 600 mm of precipitation falls, and on the eastern slope, in Chelyabinsk, 370 mm.

The distribution of precipitation is also influenced by the currents of the World Ocean. Over areas near which

HUMIDIFICATION RATIO

Some of the precipitation evaporates from the surface of the soil, and some seeps deeper.

Evaporation is the layer of water, calculated in millimeters, that can evaporate in a year under the climatic conditions of a certain area. To understand how an area is provided with moisture, the humidification coefficient K is used.

where R is the annual precipitation, and E is evaporation.

Humidity coefficient shows the ratio of heat and moisture in a given area, if K > 1, then the moisture is considered excessive, if K = 1, it is sufficient, and if K< 1 - недостаточным.

Distribution of precipitation around the globe

warm currents pass, the amount of precipitation increases, as the air heats up from the warm water masses, it rises and clouds with sufficient water content form. Over areas near which cold currents pass, the air cools and sinks, clouds do not form, and much less precipitation falls.

The greatest amount of precipitation falls in the Amazon basin, off the coast of the Gulf of Guinea and in Indonesia. In some areas of Indonesia, their maximum values ​​reach 7000 mm per year. In India, in the foothills of the Himalayas at an altitude of about 1300 m above sea level, the rainiest place on Earth is located - Cherrapunji (25.3 ° N and 91.8 ° E), where an average of more than 11,000 mm of precipitation falls in year. Such an abundance of moisture brings to these places the humid summer southwest monsoon, which rises along the steep slopes of the mountains, cools and pours down with heavy rain.

Video tutorial 2: Atmosphere structure, meaning, study

Lecture: Atmosphere. Composition, structure, circulation. Distribution of heat and moisture on Earth. Weather and climate

Atmosphere

Atmosphere can be called an all-pervading shell. Its gaseous state allows it to fill microscopic holes in the soil; water is dissolved in water; animals, plants and humans cannot exist without air.

The conventional thickness of the shell is 1500 km. Its upper boundaries dissolve in space and are not clearly marked. The atmospheric pressure at sea level at 0 ° C is 760 mm. rt. Art. The gas shell consists of 78% nitrogen, 21% oxygen, 1% other gases (ozone, helium, water vapor, carbon dioxide). The density of the air envelope changes with increasing altitude: the higher you go, the thinner the air. This is why climbers may experience oxygen deprivation. The earth's surface itself has the highest density.

Composition, structure, circulation

The shell contains layers:

Troposphere, 8-20 km thick. Moreover, the thickness of the troposphere at the poles is less than at the equator. About 80% of the total air mass is concentrated in this small layer. The troposphere tends to heat up from the surface of the earth, so its temperature is higher near the earth itself. With a rise of 1 km. the temperature of the air shell decreases by 6°C. In the troposphere, active movement of air masses occurs in the vertical and horizontal directions. It is this shell that is the weather “factory”. Cyclones and anticyclones form in it, and western and eastern winds blow. It contains all the water vapor that condenses and is shed by rain or snow. This layer of the atmosphere contains impurities: smoke, ash, dust, soot, everything we breathe. The layer bordering the stratosphere is called the tropopause. This is where the temperature drop ends.

Approximate boundaries stratosphere 11-55 km. Up to 25 km. Minor changes in temperature occur, and above it it begins to rise from -56 ° C to 0 ° C at an altitude of 40 km. For another 15 kilometers the temperature does not change; this layer is called the stratopause. The stratosphere contains ozone (O3), a protective barrier for the Earth. Thanks to the presence of the ozone layer, harmful ultraviolet rays do not penetrate the surface of the earth. Recently, anthropogenic activities have led to the destruction of this layer and the formation of “ozone holes.” Scientists claim that the cause of the “holes” is an increased concentration of free radicals and freon. Under the influence of solar radiation, gas molecules are destroyed, this process is accompanied by a glow (northern lights).

From 50-55 km. the next layer begins - mesosphere, which rises to 80-90 km. In this layer the temperature decreases, at an altitude of 80 km it is -90°C. In the troposphere, the temperature again rises to several hundred degrees. Thermosphere extends up to 800 km. Upper limits exosphere are not detected, since the gas dissipates and partially escapes into outer space.

Heat and moisture

The distribution of solar heat on the planet depends on the latitude of the place. The equator and the tropics receive more solar energy, since the angle of incidence of the sun's rays is about 90°. The closer to the poles, the angle of incidence of the rays decreases, and accordingly the amount of heat also decreases. The sun's rays passing through the air shell do not heat it. Only when it hits the ground, solar heat is absorbed by the surface of the earth, and then the air is heated from the underlying surface. The same thing happens in the ocean, except that the water heats up more slowly than the land and cools down more slowly. Therefore, the proximity of seas and oceans influences the formation of climate. In summer, sea air brings us coolness and precipitation, in winter it warms, since the surface of the ocean has not yet spent its heat accumulated over the summer, and the earth's surface has quickly cooled. Marine air masses are formed above the surface of the water, therefore, they are saturated with water vapor. Moving over land, air masses lose moisture, bringing precipitation. Continental air masses form above the surface of the earth, as a rule, they are dry. The presence of continental air masses brings hot weather in summer and clear frosty weather in winter.

Weather and climate

Weather– the state of the troposphere in a given place for a certain period of time.

Climate– long-term weather regime characteristic of a given area.

The weather can change during the day. Climate is a more constant characteristic. Each physical-geographical region is characterized by a certain type of climate. The climate is formed as a result of the interaction and mutual influence of several factors: the latitude of the place, the prevailing air masses, the topography of the underlying surface, the presence of underwater currents, the presence or absence of water bodies.

On the earth's surface there are belts of low and high atmospheric pressure. The equatorial and temperate zones are low pressure; at the poles and in the tropics the pressure is high. Air masses move from an area of ​​high pressure to an area of ​​low pressure. But since our Earth rotates, these directions deviate, in the northern hemisphere to the right, in the southern hemisphere to the left. Trade winds blow from the tropical zone to the equator, westerly winds blow from the tropical zone to the temperate zone, and polar eastern winds blow from the poles to the temperate zone. But in each zone, land areas alternate with water areas. Depending on whether the air mass has formed over land or ocean, it may bring heavy rain or a clear, sunny surface. The amount of moisture in air masses is affected by the topography of the underlying surface. Over flat areas, moisture-saturated air masses pass without obstacles. But if there are mountains on the way, the heavy moist air cannot move through the mountains, and is forced to lose some, or even all, of the moisture on the mountain slope. The east coast of Africa has a mountainous surface (the Drakensberg Mountains). The air masses that form over the Indian Ocean are saturated with moisture, but they lose all the water on the coast, and a hot, dry wind comes inland. This is why most of southern Africa is desert.