Climatic zones of the Earth
The amount of solar radiation decreases from the equator to the poles, and the air masses are formed depending on the geographical latitude. Therefore, each latitude is characterized by its signs of climate. In this way, according to latitude, climatic belts are singled out – huge territories within which the main climate indicators hardly change.
Russian climate scientist Boris Alisov, as the basis for the allocation of climatic zones, assumed the predominant types of air masses, in the names of which the belts and got their names. The climatic zones are divided into basic and transitional zones. Where the influence of one type of air mass prevails throughout the year, the main climatic zones formed. They are mirrored from the equator to the poles. There are seven main climatic zones: equatorial, two tropical, two temperate, Arctic and Antarctic.
In the equatorial climatic zone, low atmospheric pressure and equatorial air masses prevail throughout the year. The sun
In tropical zones, tropical air masses with high pressure and downward air currents dominate. Tropical air masses are always dry, since in the air coming from the equator to the tropics at an altitude of 10-12 km there is already little moisture. When the air is exhausted, the air heats up and becomes even drier. Therefore, rains here are rare. The air temperature is high. Such climatic conditions contributed to the formation here of a zone of tropical deserts and semi-deserts.
Moderate climatic zones are influenced by western winds and moderate air masses. Here four seasons are clearly pronounced. The amount of precipitation depends on the proximity of the territories to the ocean. Most precipitation falls in the western parts of Eurasia. They are brought by the western winds from the ocean. The farther to the east, those fewer precipitation, that is, the continentality of the climate
The Arctic and Antarctic climatic zones are formed under the influence of cold and dry Arctic and Antarctic air masses. These are areas of high pressure. The air temperature rarely rises above 0 °. Precipitation is low – less than 200 mm per year.
Territories where air masses change seasonally twice a year are related to transitional climatic zones. In the names of the transition belts, the prefix “sub” appears, which means “under,” that is, under the main belt. There are six such belts: two subequatorial, two subtropical, subarctic and subantarctic. Transitional climatic zones are located between the main belts, from where the corresponding air masses arrive. In July, all air masses move to the north, in January – to the south.
Thus, subequatorial climatic zones are located between the equatorial and tropical belts of both hemispheres. Therefore, they are in summer under the influence of warm and moist equatorial air masses, and in winter – warm and dry tropical. It follows that warm weather prevails throughout the year, but there is a summer rainy season and a winter drought season.
Subtropical climatic zones are transitional between tropical and temperate. In summer, warm and dry tropical air masses enter the subtropical belts, which causes hot and dry weather. In winter, the subtropics are dominated by cool and humid moderate air masses that bring the appropriate weather.
The subarctic and subantarctic belts are located between the arctic and temperate zones, from which relatively warm and humid moderate air masses enter the summer. in winter, cold and dry arctic. Therefore, the climate of the subarctic and subantarctic belts in summer is similar to the temperate climate, and in winter – the climate of the Arctic belts.
So, the climatic zones are zoned, that is, they are repeated from the equator to the poles. This is primarily due to the influence of solar radiation. The types of climate also vary on the Earth. Under the type of climate is understood a constant set of climatic indicators, characteristic for a certain period of time and a certain territory.
If you carefully consider the map of climatic zones in the atlas, you can see that the boundaries of climatic zones do not always coincide with the direction of parallels. And in some places they are significantly rejected to the north or south. This is due, first of all, to the nature of the underlying surface. Therefore, within different climatic zones, different types of climate can form. For example, in the temperate zone of Eurasia, marine, continental and monsoon types of climate are distinguished.