What is the method and basis for dividing the four seasons?

Do you know how the seasons are divided?

The seasons are divided according to the length of day and night and the change in the height of the sun. In the division of the seasons, the apparent position of the sun on the ecliptic is used as the basis, and the equinox, solstice, or four days are used as the boundary. However, the boundaries used by Eastern and Western countries to divide the seasons are not identical.

The month of each season cannot be fixed.

The first. The traditional method of dividing the four seasons in China is to take the four of the 24 solar terms as the starting point of the four seasons, and the equinoxes and solstices as the midpoint. For example, the beginning of spring is the starting point, the ecliptic longitude of the sun is 315°, the spring equinox is the midpoint, the beginning of summer is the end point, the ecliptic longitude of the sun becomes 45°, and the sun runs 90° on the ecliptic.

This is a traditional, common method.

The second. The astronomical classification (i.e., the Western taxonomy) divides the four seasons more on the climatic significance of the four seasons, and takes the equinoxes and solstices as the starting point of the four seasons, such as the spring equinox in spring and the summer solstice as the ending point. These four seasons are one and a half months later than the four seasons traditionally divided in our country.

The third. In order to accurately reflect the actual climatic conditions of various places, the four seasons are divided by climatic methods, that is, the classification method of modern scholar Zhang Baokun, and the average temperature is used to divide the four seasons. And stipulates:

The period when the average temperature is greater than or equal to 22 is summer, the period less than or equal to 10 is winter, and the period between 10 and 22 is spring or autumn.

According to this criterion, the seasons in the mid-latitudes are consistent with the climate, and the temperature changes in spring, summer, autumn and winter in the low-latitudes and near the poles are very insignificant. At the same time, in the mid-latitudes, the length of each season is also different. These are the four seasons of the climate.

For example, Beijing has 55 days in spring, 103 days in summer, 50 days in autumn and 157 days in winter. This method can be combined with the specific climate and agriculture of various places, so it is used more.

Fourth. Climatological statistics, because January is generally the coldest month, therefore, spring, March, April, May, summer, June, July, August autumn, September, October, November winter, December, January, February This four-season classification method is more suitable for temperate regions with four distinct seasons.

The four seasons refer to the four seasons that alternate in a year, namely spring, summer, autumn, and winter, with three months each. The four seasons of the year are formed because the earth revolves around the sun. Due to the existence of the yellow-red angle, the annual change of the direct point of the sun moving back and forth between the north and south latitudes of the earth is 23°26, which causes the seasonal change of the height of the sun at noon and the seasonal change of the length of day and night, resulting in the seasonal change of the amount of solar energy obtained in various places, so that the change of the four seasons is formed.

2] In ancient times, the alternation of seasons was determined according to the direction of the bucket handle, and the seven stars of the Big Dipper rotated in cycles, which was closely related to the change of seasons. The current seasons are usually determined by the position of the Earth in its orbit around the Sun. The rotation of the four seasons reflects the changes in phenology, climate and other aspects, such as spring, summer, autumn and winter.

In the southern region of China (low latitude region), the precipitation is abundant, the sunshine is sufficient, the humidity is humid, the temperature difference between winter and summer is small, and the climatic factors such as sunshine and precipitation change significantly during the seasonal transition. In the northern region (mid-latitude region), there is little precipitation, dryness, and a large temperature difference between winter and summer, and the temperature changes significantly during the seasonal transition.

1. Solar term method: astronomically the spring equinox, summer solstice, autumn equinox, and winter solstice are the beginning; In ancient China, the beginning of spring, summer, autumn and winter were the beginning of the four seasons. All are based on the position of the Earth in orbit.

2. Lunar Calendar Law: Spring is from January to March, summer from April to June, autumn from July to September, and winter from October to December. 3. Gregorian calendar:

Meteorologically, the solar calendar usually follows the solar calendar, from March to May, and from October to December is winter. 3. Gregorian calendar: meteorologically, the solar calendar usually takes March to May as spring, June to August as summer, September to childhood as autumn, and December to February of the following year as winter.

4. Seepage or selling phenology: willow leaves, peach blossoms, spring is coming; The trees are shady, the red sun is scorching, and summer has arrived; The leaves of the fruit trees fall, the water is clear and the dew is cold, and the time sequence is autumn; The grass withers and the flowers wither, the north wind howls, and the years enter winter. Understand the TV network