What are the characteristics of the vernal equinox?
The vernal equinox is one of the solar terms reflecting the changes of the four seasons and the fourth of the 24 solar terms. In ancient China, beginning of spring, Changxia, beginning of autumn and beginning of winter were used to indicate the beginning of the four seasons. The vernal equinox, summer solstice, autumn equinox and winter solstice are in the middle of each season. On the vernal equinox, the sun shines directly on the equator, and the time between day and night is equal all over the earth. Therefore, the ancient vernal equinox and autumnal equinox are also called "equinox", and there is a folk proverb that "vernal equinox and autumnal equinox are equally divided day and night".
Geographical knowledge of vernal equinox:
1, divided equally between day and night
At the vernal equinox, the sun shines directly on the equator, so the length of day and night in the northern and southern hemispheres is the same, and drinking during the day and drinking at night is 12 hours. There will only be vernal equinox and autumn equinox in a year.
2. Average distribution season
Another reason for the origin of the name vernal equinox is that it divides spring equally. In ancient times, beginning of spring and Changxia were used as spring, and the vernal equinox happened to be in the middle of three months in spring, which just split the spring in two.
3. A lot of rain
As soon as the vernal equinox arrives, the rainfall in various places increases obviously, and the temperature in many places in China exceeds 10 degrees, which is the spring temperature defined by climatology. After the spring equinox solar terms, the climate is mild, the rain is abundant and the sun is shining. In most areas, winter crops enter the spring growth stage, which is also the sowing time of early rice, so the spring equinox is still an important season for farming.