The Science Story of Spring

Beginning of spring: beginning of spring is standing, and beginning of spring is beginning of spring. Beginning of spring, one of the 24 solar terms [1], stands for "beginning", beginning of spring is the beginning of spring, and beginning of spring is when the sun reaches 3 15 degrees on February 4th or 5th every year. "Twenty-four solar terms": "The first month festival, the beginning, the beginning ... long summer, autumn and winter are the same." The ancient "Li Si" refers to the beginning of spring, summer, autumn and winter, and its agricultural meaning is "planting in spring, growing in summer, harvesting in autumn and storing in winter", which summarizes the whole process of the relationship between agricultural production and climate in the middle and lower reaches of the Yellow River. China has a vast territory, complicated geographical conditions, great climate difference and different seasons. Therefore, although "Li Si" can reflect the climate characteristics of the four seasons in the middle and lower reaches of the Yellow River, the specific climate significance of "Li Si" is not significant and cannot be applied to all parts of the country. The date of soil thawing in the middle and lower reaches of the Yellow River began in early spring. The first weather in beginning of spring should be "easterly thaw", which is basically the case, but as a symbol of beginning of spring, it is too early. In China's climatology, beginning of spring is usually defined as a day when the daily average temperature is stable above 10℃ every five days, which is inconsistent with the meaning of beginning of spring in the middle and lower reaches of the Yellow River. In late February, only South China really entered the spring. But this division method is more practical. After beginning of spring, the temperature rose, and most parts of the country began a busy spring ploughing season. In ancient China, the fifteen days in beginning of spring were divided into three periods: "The east wind thawed, the insects began to vibrate, and the fish began to get cold", which meant that the east wind warmed and the earth began to thaw. Five days after the spring, the stinging insects slowly woke up in the cave. Five days later, the ice in the river began to melt and the fish began to swim on the water. At this time, there are still broken borneol on the water, floating on the water like fish. Since the Qin Dynasty, China has always regarded beginning of spring as the beginning of spring. Beginning of spring is divided from astronomy, but in nature and people's minds, spring is warm and flowers are fragrant. Spring is growth, cultivation and sowing. In climatology, spring refers to the period when the average temperature is between 10℃ and 22℃.