What affects the climate of the Caucasus. Climate - Caucasian mountains. Hiking and car tours in the Caucasus

The climate of the Caucasus is very diverse. The northern part of the Caucasus is located within the temperate zone, Transcaucasia - in the subtropical. This geographical position significantly affects the formation of the climate in various parts of the Caucasus.

The Caucasus is a vivid example of the influence of orography and relief on climate-forming processes. Radiant energy is distributed unevenly due to different angles of its incidence and different heights of surface levels. The circulation of air masses reaching the Caucasus undergoes significant changes, encountering on its way the mountain ranges of both the Greater Caucasus and Transcaucasia. Climatic contrasts appear at relatively short distances. An example is the western, abundantly humidified Transcaucasia and the eastern, with a dry subtropical climate, the Kuro-Araks lowland. The significance of the exposure of slopes is great, which strongly affects the thermal regime and the distribution of precipitation. The climate is influenced by the seas washing the Caucasian Isthmus, especially the Black Sea.

The Black and Caspian Seas moderate the air temperature in summer, contribute to its more even daily course, moisten the adjacent parts of the Caucasus, increase the temperature of the cold season, and reduce temperature amplitudes. The plain eastern Ciscaucasia and the Kuro-Araks lowland, which extends deeply into the isthmus, do not contribute to the condensation of moisture coming from the Caspian Sea. Ciscaucasia is greatly influenced by continental air masses coming from the north, including the Arctic ones, which often significantly reduce the temperature of the warm season. The spur of high East Siberian barometric pressure often lowers the temperature of the cold season. There are cases when cold air, flowing around the Greater Caucasus from the east and west, spreads into Transcaucasia, causing a sharp drop in temperature there.

Air masses coming from the Atlantic Ocean and the Mediterranean ensure high humidity in the western parts of the Caucasus and the slopes of the western exposure ranges. Additional moisture is brought by air masses passing over the Black Sea. The influence of the Caspian Sea is less pronounced.

In general terms, the climate of the Caucasus changes significantly in three directions: from west to east towards an increase in dryness and continentality, from north to south towards an increase in total radiation and radiation balance, and in height on mountain structures, on which altitudinal zonality is clearly manifested.

The total radiation within the Caucasus ranges from 460548 J/sq. cm in the north to 586 152 J / sq. see extreme south. Annual radiation balance from 146538 to 188406 J/sq. see The amount of solar radiation depends not only on latitude, but also on cloud cover. Many peaks of the Caucasus are characterized by persistent cloudiness, so direct solar radiation here is below the average norm. To the east, it increases due to a decrease in humidity. The exceptions are Lankaran and Talysh, where the relief contributes to the condensation of water vapor and an increase in cloudiness.

The value of the total radiation and the radiation balance in different regions of the Caucasus is not the same due to the contrasts of the orography, relief, different angles of incidence of the sun's rays and the physical properties of the underlying surface. In summer, the radiation balance in some regions of the Caucasus approaches the balance of tropical latitudes, so the air temperatures are high here (Ciscaucasia and Transcaucasian plains), and in abundantly humidified areas, high evapotranspiration and, accordingly, increased air humidity are observed.

The air masses that take part in the circulation over the territory of the Caucasus are different. Basically, continental air of temperate latitudes dominates over Ciscaucasia, and subtropical air dominates in Transcaucasia. High-mountain belts are influenced by air masses coming from the west, and the northern slopes of the Greater Caucasus and the Arctic - from the north.

In Ciscaucasia, located south of the band of high barometric pressure, cold air often enters. Over the Black Sea and in the southern part of the Caspian Sea, low pressure remains. Pressure contrasts lead to the spread of cold air to the south. In such a situation, the barrier role of the Greater Caucasus is especially great, which serves as an obstacle to the wide penetration of cold air into the Transcaucasus. Usually its influence is limited to Ciscaucasia and the northern slope of the Greater Caucasus up to about 700 m. It causes a sharp drop in temperature, an increase in pressure and an increase in wind speed.

Intrusions of cold air masses are observed from the northwest and northeast, bypassing the ridges of the Greater Caucasus along the shores of the Caspian and Black Seas. The accumulated cold air rolls over low ridges. and spreads along the western and eastern coasts to Batumi and Lenkoran, causing a decrease in temperatures on the western coast of Transcaucasia to -12 ° C, on the Lankaran lowland to -15 ° C and below. A sharp drop in temperature has a disastrous effect on subtropical crops, and especially on citrus fruits. Baric gradients in these situations between Ciscaucasia and Transcaucasia are sharply contrasting, the spread of cold air from Ciscaucasia to Transcaucasia proceeds very rapidly. Cold winds of high, often catastrophic speeds are known as bora (in the Novorossiysk region) and norda (in the Baku region).

Air masses coming from the west and southwest from the Atlantic Ocean and the Mediterranean have the greatest impact on the western coast of Transcaucasia. When moving further to the east, they, overcoming the ridges located on their way, adiabatically heat up and dry up. Therefore, Eastern Transcaucasia is distinguished by a relatively stable thermal regime and low precipitation.

The mountain structures of the Lesser Caucasus and the Javakheti-Armenian Highlands contribute to the formation of a local anticyclone in winter, which causes a strong decrease in temperature. In summer, low pressure sets in over the highlands.

In the second half of summer, the Caucasus experiences the influence of the spur of the Azores barometric maximum, located within the Russian Plain between 50 and 45°N. sh. It determines the decrease in summer cyclonic activity. It is associated with a decrease in precipitation in the second half of summer (compared to the first). At this time, the importance of local convective precipitation increases due to the daily variation of air temperatures.

In the Caucasus, föhns are actively manifested, which are common for mountains with a dissected relief. They are associated with hot weather in spring and summer. Mountain-valley winds and breezes are also characteristic.

On the plains of Ciscaucasia and Transcaucasia, the average July temperature is 24--25 ° C, its increase is observed to the east. The coldest month is January. In the Ciscaucasia, the average January temperature is -4, -5 ° C, in the western Transcaucasia 4-5 ° C, in the eastern 1-2 ° C. At an altitude of 2000 m, the temperature is 13 ° C in July, -7 ° C in January, in the highest zones - 1 ° C in July, and from -18 to -25 ° C in January.

The annual amount of precipitation increases with elevation and at all levels decreases noticeably from west to east (most evenly in high belts). In the Western Ciscaucasia, the amount of precipitation is 450-500 mm, in the foothills and on the Stavropol Upland at an altitude of 600-700 m - up to 900 mm. In the east of Ciscaucasia - 250-200 mm.

In the humid subtropics of Western Transcaucasia on the coastal plains, the annual precipitation reaches 2500 mm (in the Batumi region). Maximum in September. In the Sochi region, 1400 mm, of which 600 mm falls in November-February. On the western slopes of the Greater and Lesser Caucasus, the amount of precipitation increases to 2500 mm, on the slopes of the Meskheti Range up to 3000 mm, and on the Kuro-Araks lowland it decreases to 200 mm. The Lankaran lowland and the eastern slopes of the Talysh ridge are abundantly moistened, where 1500-1800 mm of precipitation falls.

1) What features of the nature of mountains do you know from the 7th grade geography course.

Mountains are characterized by altitudinal zonality in the change of natural zones. In mountains, pressure and temperature decrease with height.

Questions in a paragraph

* Remember how much the air temperature drops when you rise for every 100 m. Calculate how much the air will cool when you rise to a height of 4000 m, if its temperature at the earth's surface is + 200C. What happens to the moisture in the air.

For every 100 m you rise, the air temperature drops by 0.60C. The temperature at an altitude of 4000 m will be -40C. The moisture in the air will begin to condense.

*Explain why there are no avalanches in the mountains of the Eastern Caucasus.

Due to the dryness of the climate, there is very little snow.

*Think about what differences will be observed in the change of altitudinal zones on the western and eastern slopes.

There are altitudinal belts of the Caucasus related to two types of vertical zonality: continental and coastal (coastal). The second one is represented in the mountains of the Western Caucasus, which are influenced by the Atlantic, humid sea air. In the east, somewhat different altitudinal belts of the Caucasus are observed, which are often called the continental, or Dagestan type of vertical zonality.

Questions at the end of the paragraph

1. Name the main features of the nature of the highlands and explain their reasons.

A large amount of precipitation, a short warm season, the dependence of natural conditions on the height of mountains and the exposure of slopes, the spread of glacial landforms, altitudinal zonality.

2. Give a description of the climate of the Greater Caucasus, explain how the climate of the foothills differs from the highlands.

With the exception of the highlands, the climate in the North Caucasus is mild and warm; on the plains, the average temperature in July exceeds 20 ° C everywhere, and summer lasts from 4.5 to 5.5 months. Average January temperatures range from -10 to +6°C, and winter lasts only two to three months. The city of Sochi is located in the North Caucasus, where the warmest winter in Russia is with a January temperature of +6.1 ° С. The climate of the highlands is very different from the plains and foothills. The first main difference is that much more precipitation falls in the mountains: at an altitude of 2000 m - 2500-2600 mm per year. The second difference in the climate of the highlands is a decrease in the duration of the warm season due to a decrease in air temperature with height. The third difference of the alpine climate is its amazing diversity from place to place in connection with the height of the mountains, the exposure of the slope, proximity or distance from the sea. The fourth difference is the peculiarity of atmospheric circulation.

3. Using Figure 102, explain the features of the altitudinal zonation of the Greater Caucasus.

There are altitudinal belts of the Caucasus related to two types of vertical zonality: continental and coastal (coastal). The second one is represented in the mountains of the Western Caucasus, which are influenced by the Atlantic, humid sea air. We list the main altitudinal belts from the foothills to the peaks:

1. Meadow steppes, interrupted by curtains of oak, hornbeam, ash (up to 100 m).

2. Forest belt.

3. Subalpine crooked forests and tall grass meadows (at an altitude of 2000 m).

4. Low-grass alpine meadows, rich in bluebells, cereals and umbrella plants.

5. Nival zone (at an altitude of 2800–3200 m).

The climatic features of the Greater Caucasus are determined by the altitudinal zonality and the rotation of the mountain barrier formed by it at a certain angle to the western moisture-bearing air flows - the Atlantic cyclones and the Mediterranean western air currents of the middle layers of the troposphere. This rotation has a decisive influence on the distribution of precipitation.

The wettest is the western part of the southern slope, where more than 2500 mm of precipitation falls annually in the highlands. The record amount of precipitation falls on the Achishkho ridge near Krasnaya Polyana - 3200 mm per year, this is the wettest place in Russia. Winter snow cover in the area of ​​the meteorological station Achishkho reaches 5-7 meters!

In the east of the Central Caucasus in the highlands falls up to 1500 mm per year, and on the southern slope of the Eastern Caucasus only 800-600 mm per year.

By the nature of the air masses, the southern slope of the Greater Caucasus belongs to the subtropical zone, the border of which with the temperate zone is emphasized by the barrier of the highlands. The west of the lower part of the southern slope has a humid subtropical climate, while the east has a semi-dry climate. The northern slope of the Greater Caucasus is generally drier than the southern one.

In the mountains of the Greater Caucasus, on a relatively small area, there is a wide range of climatic zones with pronounced zonality in height: humid subtropics of the Black Sea coast; continental dry (in the east to semi-desert) climate with hot summers and short but cold winters; precipitation (especially in the western part) and snowy winters (in the Krasnaya Polyana area, on the watershed of the Bzyb and Chkhalta rivers, the snow cover reaches 5 m and even 8 m). In the zone of alpine meadows, the climate is cold and humid, winter lasts up to 7 months, the average temperatures of August - the warmest month - range from 0 to 10 ° C. Above is the so-called nival belt, where the average temperature of even the warmest month does not exceed 0 °. Precipitation here falls mainly in the form of snow or grains (hail).

The average January temperatures at the foot of the mountains are -5°С in the north and from 3° to 6°С in the south at an altitude of 2000 m -7-8°С, at an altitude of 3000 m -12°С, at an altitude of 4000 m -17°С . The average July temperatures at the foot of the mountains in the west are 24°С, in the east up to 29°С at an altitude of 2000 m 14°С, at an altitude of 3000 m 8°С, at an altitude of 4000 m 2°С.

In the Greater Caucasus, the height of the snow line, rising from west to east, ranges from 2700 m - 3900 m above sea level. Its northern mark is different for the northern and southern slopes. In the Western Caucasus, these are 3010 and 2090 m, respectively, in the Central - 3360 and 3560 m, in the East - 3700 and 3800 m. The total area of ​​modern glaciation of the Greater Caucasus is 1780 km¤. The number of glaciers is 2047, their tongues descend to absolute levels: 2300-2700 m (Western Caucasus), 1950-2400 m (Central Caucasus), 2400-3200 m (Eastern Caucasus). Most of the glaciation occurs on the north side of the GKH. The distribution of the glaciation area is as follows: Western Caucasus - 282 and 163 sq. km Central Caucasus - 835 and 385 sq. km East Caucasus - 114 and 1 sq. km, respectively.

Caucasian glaciers are distinguished by a variety of forms. Here you can see grandiose icefalls with seracs, ice grottoes, tables, mills, deep cracks. Glaciers carry out a large amount of detrital material that accumulates in the form of various moraines on the sides and at the tongue of the glaciers.

Many factors influence the climate of the Caucasus. The most important of them are latitudinal zonality and vertical zonality. However, the actions of these main factors are largely corrected by the peculiarities of the geographical location and topography.

In addition, the climate of different parts of the Caucasus is greatly influenced by the proximity of the Black and Azov Seas in the west and the Caspian Sea in the east. All these factors have created a variety of climatic and forest conditions in the Caucasus.

The high mountain ranges in the Caucasus influence the advancement and distribution of baric phenomena. Thus, the main Caucasian ridge protects the territory of Transcaucasia from the invasion of cold air masses approaching from the north. These air masses flow around the ridge and enter Transcaucasia from the west and east, being moistened due to contact with the Black and Caspian Seas and somewhat warming up under the influence of the warm land surface.

Mountains, cutting in different directions the territory of Transcaucasia, and solar radiation continue to modify the climate of the Caucasus, affecting the direction and speed of air masses, their rise, etc.

All this creates complexity and diversity of climate elements - air and soil temperatures, the amount, intensity and distribution of precipitation, relative humidity, wind direction and speed, etc.

The intensity of solar radiation increases with the elevation of the terrain. However, the main role belongs not to the sum of heat and solar radiation, but to the air and soil temperature. Due to the intensity of solar radiation in the mountains, there are large fluctuations in air temperatures during the day.

The soil gets very warm on sunny days, especially on the slopes of southern exposure. As a result, the soil temperature changes less with increasing altitude than the air temperature, and the difference between air and soil temperatures becomes very small. At night, the surface layer of soil on the slopes noticeably cools, but in deeper layers its temperature exceeds the air temperature.

According to the degree of moisture in the Caucasus, there are: humid subtropical regions of the Black Sea coast of the Krasnodar Territory, Western Georgia and South-East Azerbaijan; humid regions of the Northern and Western Caucasus; dry regions of Eastern Georgia, Western Azerbaijan, Armenia, Dagestan.

The climate of the Caucasus can be traced with each rise in altitude, according to scientists, for every 100 meters of rise, the amount of precipitation increases by 20%, in the Crimea by 14-15%.

Precipitation and rainy days are greatly influenced by local geographic factors. Thus, under the influence of the Black Sea in the adjacent areas of Western Georgia and the Krasnodar Territory, the average annual precipitation exceeds 1000 mm, reaching 3000 mm in the coastal strip of Adjara. In dry mountainous areas, the average annual precipitation is 300-350 mm, decreasing in some years to 100 mm.

The climate of the Caucasus is very diverse, which is primarily due to the influence of the relief.

The Caucasus is located on the border of the temperate and subtropical climatic zones. The differences between them are intensified by the mountains of the Greater Caucasus, which hinder the transfer of cold air masses from the north to the Transcaucasus and warm air masses from the south to the Ciscaucasia. The North Caucasus belongs to the temperate zone, Transcaucasia - to the subtropical. The differences between them are especially noticeable in air temperature.In the North Caucasus, everywhere, with the exception of the highlands, there is a lot of heat. On the plains, the average temperatures in July everywhere exceed 20°, and summer lasts from 4.5 to 5.5 months. The average January temperatures fluctuate in different areas from -10° to +6°, and winter lasts only two to three months. The rest of the year is occupied by transitional seasons - spring and autumn.

In the Greater Caucasus, starting from a height of about 2000 m, and in the Transcaucasian Highlands, the role belongs to the western air transport, in connection with which the influence of the Atlantic and the Mediterranean Sea increases. Therefore, in the highlands, the climate is more humid.

The complex mountainous relief creates a wide variety of local climates in the Caucasus, and the previously outlined large geomorphoslogical units differ in climatic terms.

The diversity of the climate of the Caucasus determines the differences in the agricultural use of its territory. The economic importance of the Transcaucasian subtropical regions, protected by the Greater Caucasus mountain barrier, is especially great, where a whole range of varieties of subtropical climate is observed, ranging from humid, which allows the cultivation of tea and citrus fruits, to dry, suitable for growing cotton and other crops that require an abundance of sunlight.