The meaning of the four seasons

The four seasons refer to a year and a cycle. Because the four seasons refer to spring, summer, autumn and winter, which is exactly one year.

Four seasons are four seasons that appear alternately in a year, and each season has three months. The formation of four seasons is because the earth revolves around the sun, and the movement of stars is closely related to the changes of seasons.

The rotation of the four seasons reflects the changing laws of phenology and climate such as spring, long summer, autumn harvest and winter storage. Spring ranks first among the four seasons, and a new cycle begins. Spring is the season for all things to grow, and sowing in spring. The so-called "one year's plan lies in spring".

The commonly used methods of season division mainly include "solar terms method" and "temperature method". Traditionally, China begins with four solar terms (beginning of spring, Changchun, beginning of autumn and beginning of winter).

Zhang Baokun, a modern scholar, put forward a new standard for the division of seasons. The average temperature (the average temperature for five consecutive days) is beginning of winter, and when it rises above 22℃, it is long summer. The average temperature in spring or autumn is 10-22℃.

geographical phenomena

China has a vast territory in low, middle and high latitudes. Low latitude generally refers to the spatial range between 30 degrees north and south latitude on the earth's surface, that is, the area between 30 degrees north latitude and 30 degrees south latitude, including tropical and subtropical hot spots, which is the area where global solar radiation and heat are concentrated.

Mid-latitude is the latitude zone between 30 and 60 degrees north latitude. The air masses prevailing in high and low latitudes overlap each other in this area, with frequent cyclone activities and obvious temperature changes. High latitude refers to the area between 60 degrees north and south latitude and the north and south poles on the earth's surface, which is the weakest area on the earth's surface to receive solar radiation.

The southern region of China (low latitude region) is rich in precipitation, abundant in sunshine, high in humidity, small in temperature difference between winter and summer, and the climatic factors such as sunshine and precipitation change obviously with the seasons. The northern region (mid-latitude region) is characterized by less precipitation, dryness, and large temperature difference between winter and summer. When the season changes, the obvious change of climate factors is temperature.