Brief introduction of information about vernal equinox

1, the vernal equinox is one of the 24 solar terms and the fourth solar term in spring. The fingers do not match, the longitude of the sun reaches 0, and the festival is held on March 19-22 of the Gregorian calendar every year. The vernal equinox is of great significance in astronomy. On this day, the northern and southern hemispheres are divided equally day and night. Since then, the direct position of the sun has continued to shift from the equator to the northern hemisphere. The days in the northern hemisphere are longer than the nights, while the southern hemisphere is the opposite. In terms of climate, there are also obvious characteristics. In addition to the Qinghai-Tibet Plateau, Northeast China, Northwest China and North China, China has entered a beautiful spring.

2, the meaning of the vernal equinox, one refers to the day and night equally divided, each 12 hours; Second, in ancient times, it was spring from beginning of spring to long summer, and the vernal equinox happened to be in the three months of spring, and spring was equally divided. After the vernal equinox, the climate is mild, rainy and sunny. During the vernal equinox, there are some folk customs in China, such as flying kites, eating spring vegetables and laying eggs.

3. On the day of the vernal equinox, the sun shines almost directly on the equator of the earth, and the whole world is almost as long as day and night (regardless of the refraction of the sun light by the atmosphere and the shadow in the morning). The seasons in the northern and southern hemispheres are opposite. In the northern hemisphere, it is the vernal equinox, and in the southern hemisphere, it is the autumnal equinox.

At the vernal equinox, the direct point of the sun is on the equator. Theoretically, the earth's day and night are equal in length. After the vernal equinox, the direct point of the sun continued to move northward, and the days in the northern hemisphere became longer and shorter, and the nights in the southern hemisphere became shorter and shorter.