The main reason for the low precipitation in the Eurasian continent

The main reason for the low precipitation in the Eurasian continent is that it is far away from the sea and it is difficult for water vapor to reach it.

According to the knowledge we have learned, the main factors that affect precipitation include latitude, sea and land location, and topographic factors. There is little precipitation in the interior of the Eurasian continent, which is mainly affected by the location of the sea and land. It is deep inland and far away from the ocean, so water vapor is difficult to reach, so precipitation is scarce in the interior of the Eurasian continent.

Main factors affecting precipitation:

1. Latitude position determines the influence of pressure belts and wind belts on precipitation. The relationship between pressure zones, wind zones, precipitation and distribution patterns is as follows: Downdrafts prevail in high pressure zones. During the sinking process, the temperature continues to rise, the saturation content of water vapor continues to decrease, and the air becomes drier and drier, making it impossible to form precipitation. , what a sunny weather.

For example, in the Sahara tropical desert area, under the control of subtropical high pressure, downdrafts prevail throughout the year, making it hot and dry; my country's Yangtze River Basin has the formation of drought weather in midsummer; the Antarctic region has become a rare zone; and in In areas controlled by low air pressure, rising air currents prevail, and the upward cooling can easily reach a supersaturated state, which often condenses rainfall and forms rainy areas. For example, equatorial areas are under the control of low air pressure all year round, making it rainy all year round.

The global wind belts include polar easterly belts, westerly belts, and trade wind belts. The westerly belts and trade wind belts have a greater impact on precipitation. The main influence of wind belts on precipitation is by bringing ocean water vapor to Precipitation forms on the mainland. According to the relationship between the wind belt and the continent, it can be divided into windward shore and leeward shore. The windward shore is often affected by the water vapor brought by the wind belt from the ocean and has more precipitation, while the wind on the leeward shore comes from the land. The air blowing toward the ocean is dry and precipitation is low.

The west coast of the continent at mid-latitudes is the windward coast of the westerly winds and has a lot of precipitation, such as western Europe and the western coasts of North and South America; the east coast of the low-latitude continents is the windward coast of the trade winds and has a lot of precipitation, such as eastern Madagascar. The formation of the tropical rainforest climate in northeastern Australia and the southeastern Brazilian plateau is all related to the trade winds, while the formation of the tropical desert climate in the west and the dry season of the savannah climate is related to the trade winds blowing from the land to the ocean.

2. Atmospheric circulation (monsoon) In the monsoon climate zone, the properties of winter and summer monsoons are different, and their impact on precipitation is also different. The summer monsoon blows from the ocean to the land, bringing a large amount of ocean water vapor to the land, which may cause precipitation.

The winter wind blows from the land to the ocean and is dry in nature. It generally does not form precipitation and the weather is sunny. For example, in the East Asian monsoon area, summers are hot and rainy, and winters are cold and dry; in the South Asian monsoon area, a rainy season forms when the southwest monsoon controls it, and a dry season forms when the northeast monsoon controls it.

3. Sea and land distribution (distance from the sea). Generally speaking, the closer to the sea, the greater the influence of the ocean. The farther away from the sea, the harder it is for ocean water vapor to reach and less precipitation. Therefore, the general rule of precipitation distribution is that there is more along the coast and less inland.

For example, my country's precipitation distribution pattern decreases from the southeastern coast to the northwest inland, and the precipitation in the arid and semi-arid areas of the northwest gradually decreases from the east to the west. These are all affected by the distance from the sea.