Are the four seasons distinguished by the lunar calendar or the solar calendar?

There are many ways to distinguish the four seasons, such as according to the lunar calendar (that is, Wuhou season), according to the astronomical season, according to the climate season and so on.

1, the phenological season takes four solar terms (beginning of spring, Changxia, beginning of autumn and beginning of winter) as the starting point of the four seasons, and bisection and bisection to one as the midpoint. For example, in spring, beginning of spring is the starting point, the solar calendar is 3 15, the spring is the midpoint, the long summer is the end point, the solar calendar becomes 45, and the sun runs 90 on the ecliptic. This is a traditional and commonly used method.

The astronomical season is determined by the position of the earth on the ecliptic. That is, from beginning of spring to long summer is spring, from long summer solstice to beginning of autumn is summer, from beginning of autumn to beginning of winter is autumn, and from winter solstice to beginning of spring is winter. Spring, summer, autumn and winter are 9 1 day, 94 days, 92 days and 88 days respectively.

China folk customs adopt the lunar calendar, 1, and February and March are spring; April, May and June are summer; July, August and September are autumn; 10, 1 1,1February is winter. The year of leap month is an exception, basically similar to the former.

3. Astronomical season reflects the seasonal variation of solar height in a year. Because the solar radiation reaching the ground is influenced by the ground and land and sea, its thermal effect lags behind that of solar radiation by about one month, so March, April and May in the solar calendar are often regarded as spring. June, July and August are summer; 9, 10, 1 1 is autumn; 12, 1, February is winter.

The date of astronomical season is fixed and easy to remember, but it cannot reflect the regional characteristics and differences.

4. Climatic season is divided into seasons with average climatic temperature, the period with average climatic temperature of 22℃ is summer, and the period of 10 ~ 22℃ is spring and autumn, which is more in line with people's understanding of the four seasons and their feelings of cold and warm.

Extended data:

The formation of the four seasons is because the earth is spherical, and the solar radiation projected on the ground changes in the latitude direction. The rotation axis of the earth is not perpendicular to its orbital plane. More importantly, the intersection angle between the ecliptic and the equator changes between plus and minus 23 ~ 27 degrees a year, which correspondingly changes the length of day and night, the height of the sun and the amount of solar radiation received. This is the fundamental reason for the alternation of the four seasons.

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.

At different latitudes, seasonal changes have different characteristics. In the relative climate zone of the northern and southern hemispheres, the seasons are also relative: autumn to spring, summer to winter.

References:

Baidu encyclopedia-four seasons