How to understand "thunder before the earthquake, the clouds will open for 49 days"

Surprisingly, it was called "Qi Zhe" in ancient times, which was the third of the 24 solar terms and the beginning of the official calendar of Uzuki. The time point is between March 5 and 6 in Gregorian calendar, when the sun reaches 345 longitude. "Twenty-four solar terms": "February Festival ... everything is shocked and thunderous, so it is called a thorn. It's a leaving thorn. "

The time of panic is correct between March 5 and 6 of the Gregorian calendar. Some people used to say that "the time is around the first day of the second lunar month", which is wrong. The dates of lunar and solar calendars are quite different.

At this time, the weather is getting warmer and there is gradually spring thunder. Animals hide in the soil in winter and don't drink or eat, which is called "sting". "Thunder" is the day when God wakes animals with thunder. At this time, most parts of China have entered the spring ploughing season.

Thorns and thunder are the most striking. For example, "before the earthquake, thunder thundered and the clouds opened for forty-nine days." The "shocking" solar term is the moment when it is cold and warm. According to the cold and warm weather, there are proverbs to predict the weather in the later period: "Those who are cold in Beijing are warm in spring" and so on. The wind with prickly knots is also used as a basis for predicting the weather in the later period. For example, "if you are afraid of the north wind, you will spend the winter from the beginning" and "if you are afraid of the south wind, you will plant seedlings later".

Modern meteorological science shows that the occasional thunder before and after the "fright" is caused by the increase of earth humidity, which leads to the rise of hot air near the ground or the strong and frequent activity of hot and humid air in the north. Judging from the natural phenological process in various parts of China, due to the large span between north and south, the time when spring thunder begins to ring is different in the morning and evening. Thunder can be heard in southern Yunnan around the end of 1, and the first thunder day in Beijing is in late April. The saying that "thunder begins with you" only conforms to the climate law of the Yangtze River basin.