Solar terms and phenology in the twenty-four solar terms

Twenty-four solar terms are symbols of China's traditional meteorology, agricultural observation and life culture. They are divided into four seasons: spring, summer, autumn and winter, and each season contains six solar terms.

In spring, the first solar term is beginning of spring, and its first appearance is the thawing of the east wind, which indicates the beginning of spring. The next solar term is rain, which first appeared as rex offering sacrifices to fish, meaning that fish began to gain weight with the arrival of spring. Then, it was a fright, starting from the time when the peach blossoms were in bloom, indicating that the peach blossoms were in full bloom in spring and reached a climax. Other spring solar terms include vernal equinox, Tomb-Sweeping Day, and Grain Rain, which are marked by equal length of day and night, clean vegetation, and sowing grain.

In summer, the first solar term is long summer, and the first sound of insects appears, which indicates the beginning of summer. The next solar term is Xiaoman, and its initial appearance is bitter vegetable show, which means bitter vegetable is flourishing. Then came the Miscanthus. At first, snipes began to sing, indicating the arrival of summer. Other summer solar terms include summer solstice, slight heat and great heat, which are marked by the difference in the longest day and the degree of heat.

The first solar term in autumn is beginning of autumn, and the first cool breeze indicates the beginning of autumn. The next solar term is summer. At first, the eagle is a sacrificial bird, which means that the eagle begins to store food for winter. Then there is the White Dew. Its initial appearance is the arrival of wild geese, which means that wild geese begin to fly south. Other autumn solar terms include autumnal equinox, cold dew and first frost, which are marked by equal length of day and night, rising cold and frosting respectively.

The first solar term in winter is beginning of winter. Its initial appearance is that water begins to freeze, which indicates the beginning of winter. The next solar term is light snow. At the beginning, the rainbow disappeared, indicating that the rainbow no longer appeared. Then there is the heavy snow. In its initial stage, the EMU stops singing, which means that the EMU stops singing. Other winter solar terms include winter solstice, slight cold and severe cold, which are characterized by the shortest day and different degrees of cold.

Generally speaking, each solar term has its own specific phenological phenomena, including changes in animals and plants, changes in temperature and humidity. It can be used as an important reference for agricultural activities and daily life.