In summer, due to the difference of thermal properties between land and sea, the temperature in Chinese mainland is high and controlled by low pressure; The ocean temperature is low and controlled by high pressure.
At this time, the Asian continent is controlled by the Asian low (Indian low), while the South Pacific is controlled by the high. The wind flows from high pressure to low pressure. So the southern hemisphere blows the southeast monsoon, which meets the equator. Due to the influence of geostrophic deflection, the southwest monsoon is in the east.
Winter: Northeast monsoon prevails.
In winter, due to the difference of thermal properties between land and sea, the temperature in Chinese mainland is low and controlled by high pressure. The ocean temperature is very high and is controlled by low pressure.
At this time, Asia is controlled by the Asian high (Mongolian Siberian high), and the ocean is dominated by low pressure, so the northeast monsoon prevails.
The summer monsoon is stronger because the source of Xia Feng is closer.
In addition, the monsoon climate in East Asia and South Asia is affected by the difference of thermal properties between land and sea, but the south Asian monsoon is also affected by the movement of the wind belt in the pressure zone.