What are the winter Xia Feng directions and characteristics of East Asian monsoon and South Asian monsoon?

When winter winds prevail, the climate in East Asia is characterized by low temperature, dryness and little rain. When the summer monsoon prevails, the weather is hot, humid and rainy.

2. South Asian monsoon

In summer, the pressure belt and wind belt move northward, and the equatorial depression moves to the northern hemisphere. The southeasterly trade winds originally located in the southern hemisphere moved northward to the Indian Peninsula, and became southwesterly winds due to geostrophic bias, which is the summer monsoon in South Asia. Because the southwest wind in summer is stronger than the northeast wind in winter, it is called southwest monsoon. Dry in winter and humid in summer are the main climatic characteristics of the South Asian monsoon.

Extended data:

First, the causes of the East Asian monsoon

There are obvious thermal differences between Asia and the Pacific. In winter, a cold high pressure formed in Mongolia and Siberia cut off the sub-polar low pressure belt. There is a pressure gradient force among Mongolian high, Pacific low and equatorial low, which is influenced by geostrophic bias to form an anticyclone, and the northerly wind moves south, affecting a large area of East Asia, which is an East Asian winter wind.

In summer, a thermal depression forms in India, cutting off the subtropical high. On the ocean where the subtropical high is broken and reserved, there is a high pressure center in the North Pacific, and the southerly airflow of the North Pacific high affects East Asia, which is the East Asian summer monsoon.

Second, the formation of monsoon.

Monsoon is a kind of wind system with wide prevalence and obvious seasonal variation of wind direction. With the seasonal change of wind direction, the weather and climate also have obvious seasonal changes. The word "monsoon" comes from Arabic word "mausim", which means season. In ancient China, trade winds were called, which meant that the direction of this wind always changed with the seasons.

The main reason for the formation of monsoon is the seasonal variation of thermal circulation between land and sea. In summer, the heating of the mainland is stronger than that of the ocean, and the pressure changes slowly with the height above the ocean. So when it reaches a certain height, it produces a horizontal pressure gradient from the mainland to the ocean, and the air points from the mainland to the ocean, forming a high pressure on the ocean.

The mainland forms a low pressure, and the air blows from the ocean to the mainland, forming an airflow opposite to the high altitude, which constitutes the summer monsoon circulation. In China, there are southeast monsoon and southwest monsoon. Summer monsoon is especially warm and humid.

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