Why does the north wind often blow in winter and the south wind in summer?

Most coastal areas in my country have southeasterly winds in summer and northwesterly winds in winter. This prevailing wind direction that changes with the seasons is called monsoon. With the change of this prevailing wind direction, it brings about obviously different winds. Weather and climate, when the winter monsoon prevails, the air flows from the northwest continent, and the air at this time is cold and dry, with little precipitation; when the summer monsoon prevails, the air flows from the southeastern ocean, and the air at this time is warm It is humid and precipitation increases. The most obvious monsoon phenomenon in the world is in eastern and southern Asia, so the southeastern region of my country has become a powerful monsoon area. The wind directions here in winter and summer are almost opposite. For example, the northerly winds in Shanghai in January (Including northwest wind, north wind and northeast wind) is 62%, that is to say, 100 times of wind direction observation, 62 times are northerly wind, southerly wind in July is 57%; northerly wind in Guangzhou in January is 55%, The southerly wind in July is 52%. The winter and summer monsoons cause different weather and climate characteristics. The most important and obvious ones are dry winters and rainy summers. Why is the monsoon particularly obvious in the southeastern part of China? This starts with the reasons for the formation of the monsoon. . We know that the temperature of the sea and land is different in winter and summer. The ocean is warmer than the land in winter, and the ocean is colder than the land in summer. The temperature is different, and the air pressure is also different. In winter, the temperature on the continent is lower and the air pressure is higher, and the air temperature and pressure on the ocean are higher. Lower; on the contrary in summer, the temperature is lower and the pressure is higher on the ocean, and the temperature is higher and the pressure is lower on the continent. Since the air pressure difference occurs between the sea and the land, the air must flow from places with high pressure to places with low pressure, thus forming The wind direction is different between the sea and the land in winter and summer, from land to sea in winter and from sea to land in summer. The greater the temperature difference between the sea and the land, the greater the air pressure difference, and the stronger the monsoon will be. In some places around the world, the monsoon phenomenon is not significant. This This is because the differences in temperature and air pressure between the sea and the land in these places are not large and are covered up by the original wind. The reason why the monsoon in southeastern Asia is strong is related to the geographical location and the land and sea situation. Asia is connected with Europe. The land is almost connected to Africa. It is only separated by the Red Sea. To the east and south of this huge land are vast oceans. The temperature and air pressure differences between the sea and the land are very large. In winter, there are It is controlled by strong high pressure, and is controlled by strong low pressure in summer. These high pressure centers and low pressure centers are generated in places where the temperature difference between sea and land is the largest. Southeast Asia is located in the zone between these high and low pressures. The winter and summer winds are particularly prevalent.