What does the season mean?

Extended data:

The season refers to the period of "spring, long summer, autumn harvest and winter storage" that appears periodically every year. Different regions have different divisions of seasons. According to the tradition of China, a year is divided into four seasons: spring, summer, autumn and winter. When the season changes, precipitation, dry humidity and other factors in southern China change obviously.

In the northern region, the changes of these factors are not obvious, but the temperature changes obviously. China's tradition began with the division of four seasons by "Four Stands". In the west, the division of the four seasons begins with "one divides into two".

The fundamental reason for the seasonal change is that the earth's axis of rotation is not perpendicular to its orbital plane, and the deflection angle is 23 degrees and 26 minutes (the angle of ecliptic).

In different seasons, the solar illumination received by the northern and southern hemispheres is unequal and changes periodically. The sunny hemisphere is summer and the other half is winter. Spring and autumn are transitional seasons. When the direct point of the sun is close to the equator, the sunshine conditions in the two hemispheres are similar, but the trend of seasonal development is still opposite-when it is autumn in the southern hemisphere, it is spring in the northern hemisphere.

There are many ways to divide the four seasons, the most common ones are:

Traditionally, the four seasons in China begin with the "Four Stands", such as beginning of spring, which is the beginning of spring. In the west, the four seasons start from the vernal equinox, for example, the vernal equinox is the beginning of spring.

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℃.

Division of solar terms: among the 24 solar terms, beginning of spring (February 4th or 5th), Changxia (May 5th or 6th), beginning of autumn (August 7th or 8th) and beginning of winter (165438+1October 8th or 9th) are designated as the start of the four seasons.

Astronomical divisions: spring equinox (March 2 1), summer solstice (June 2 1), autumn equinox (September 22) and winter solstice (February 2 1) are the beginning of the four seasons in the northern hemisphere.

Temperature classification: in meteorological departments, March to May is usually spring, June to August is summer, September to 1 65438+1October is autumn, 12 to February is winter,1,April, July,/kloc-0.

Lunar calendar division method: the folk custom uses the lunar month to divide the four seasons. Lunar calendar1~ March is spring, April-June is summer, July-September is autumn, and 10 ~ 12 is winter. The first day of the first month is the first day of the year and the first day of spring, so it is also called the Spring Festival.