Climatic characteristics controlled by subtropical high

The relationship between pressure area and precipitation is generally believed that under the control of high pressure area, there are fewer opportunities for precipitation, while under the control of low pressure area, there are more opportunities for precipitation. Subtropical high pressure area and polar high pressure area: Downstream is prevalent, and precipitation opportunities are few. The reason is that the air flow sinks and the temperature is getting higher and higher, which is not conducive to water vapor holding. Equatorial low-pressure area and sub-polar low-pressure area: updraft prevails and there are many opportunities for precipitation. The reason is that the air flow rises and the air resistance gradually decreases, which is convenient for water vapor condensation.

China is affected by the subtropical high belt as follows. The weather conditions are different in different parts of the subtropical high. In the subtropical high area, the weather is generally sunny, so when it controls a certain area for a long time, it will often cause long-term high temperature and drought in the area, but when the conditions are suitable, there will also be local thunderstorm weather; On the south side of subtropical high, typhoons are frequent. In its easterly airflow, easterly waves often form and move westward, affecting Guizhou, the east of Guangxi and the south of the Yangtze River, causing thunderstorms and heavy rains. On the north and northwest sides of the subtropical high, due to the southerly airflow in the west, a large amount of water vapor is brought from the sea. When encountering weather systems such as westerly trough or vortex, a wide range of rain belts will be produced.

Distribution law of subtropical high pressure area: subtropical high pressure area is located in the warm high pressure of subtropical area. It is located near 30 degrees north and south latitude. This high-pressure belt is the dividing line between the prevailing westerly belt and the easterly belt, and the westerly belt is on the high latitude side. Controlled by subtropical high, the weather is fine, and its northwest side is the southwest airflow jump control area (over-rain area).

The high pressure between tropical and temperate zones is called subtropical high, which is usually called the Pacific subtropical high that controls the Pacific region. It generally moves between10 ~ 40 N with seasonal changes.