The moving direction of Guang Zhouta's sun shadow at the vernal equinox

"On the day of the vernal equinox, Guang Zhouta's shadow moved from southwest to southeast. The sun shadow faces southwest at sunrise and southeast at sunset. From the vernal equinox to the summer solstice, with the direct point of the sun moving northward, the rising and setting directions of the sun gradually move northward; From summer solstice to autumnal equinox, the direct point of the sun moves south, and the rising and falling direction of the sun also moves south gradually.

Guang Zhouta (23 N,113 E), also known as Guangzhou New TV Tower, is the tallest building in Guangzhou, facing the Pearl River New Town across the river. On the day of vernal equinox, the moving time of "Little Man's Waist" tower shadow is about 12 hour.

The vernal equinox is one of the 24 solar terms and the fourth solar term in spring. The meridian of the sun reaches 0, and [2 1] intersects 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. Climatically, 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.