How is the cold wave formed?

The strong cooling weather process in China. The weather forecast stipulates that when the temperature drops by 10°C within 24 hours due to the intrusion of cold air from the north, and the lowest temperature during the process reaches below 5°C, it is defined as a cold wave weather process. Sometimes the intrusion of cold air from the north does not meet this standard, but the temperature drop is significant, so it is generally called strong cold air. In areas where cold waves or cold air fronts pass through, there is often not only strong cooling, but also strong winds and precipitation (rain, snow) weather phenomena. The formation of the cold wave is due to the continuous accumulation and strengthening of cold air masses in Siberia in winter. When it becomes a strong cold high pressure, guided by the northwest airflow at the rear of the high-altitude low-pressure trough, it invades southward in a large scale, thus forming a cold wave in the vast area north of the Nanling Mountains in my country. Or strong cooling weather process. There are three main routes for the cold wave that invades my country: ① West route: Entering Xinjiang from western Siberia and advancing to the southeast via the Hexi Corridor; ② Middle route: After entering my country from central Siberia and Mongolia, it goes south via the Hetao area and central China; ③ From eastern Siberia Or eastern Mongolia enters Northeast my country and goes south through North China.

Cold wave: The merits outweigh the faults

Cold wave, that is, a large-scale strong cold air moving southward like a tide, causing severe cooling and strong winds along the way.

The "passing" of the cold wave has left the deepest impression on people, and it seems that whenever it is mentioned, it will be associated with disastrous weather.

But few people seem to mention the benefits of cold waves to humans. Research and analysis by geographers show that cold waves contribute to heat exchange on the earth's surface. As the latitude increases, the solar radiation energy received by the earth gradually weakens, so the earth forms tropical, temperate and cold zones. The cold wave carries a large amount of cold air to the tropics, causing a large-scale exchange of ground heat, which is very helpful for maintaining the ecological balance of nature and maintaining the prosperity of species.

Meteorologists believe that the cold wave is the guarantee of good weather. Affected by the monsoon, our country has a dry climate in winter, which is the dry season. But whenever a cold wave invades the south, it often brings widespread rain and snow, which alleviates winter drought and benefits crops. Why has the farmer's proverb "Auspicious snow heralds a good harvest" been passed down among the people for thousands of years? This is because the nitrogen content in snow water is high, more than five times that of ordinary water, which can greatly increase the nitrogen in the soil. Snow water can also accelerate the decomposition of organic matter in the soil, thereby increasing the organic fertilizer in the soil. Heavy snow covers overwintering crops, acting like a quilt to resist cold and keep warm.

There is a saying that "if the winter is not cold, the coming year will be poor", which also has its scientific truth. Crop pest control experts believe that the low temperature brought by the cold wave is currently the most effective natural "insecticide". It can kill a large number of pests and germs lurking in the soil for the winter, or inhibit their growth, reducing pests and diseases in the coming year. According to survey data from agricultural technology stations in various places, pesticides can be saved by more than 60% in years with heavy snowfall.

Cold waves can also bring wind resources. Scientists believe that wind is a pollution-free and valuable power resource.

The world-famous Miyakojima Wind Power Station in Japan has a power generation efficiency that is 1.5 times that of normal times during cold waves