What is the main air pressure system of cold wave in China?

Cyclone system and polar high pressure form the main pressure system of cold wave in China.

There are roughly three routes that affect the cold wave in China:

1, one is west road. This is the earliest and most frequent route in China. Strong cold air starts from the North Pole, goes south through western Siberia, enters China and Xinjiang, and then invades North China, Central Plains, South China and even Southwest China along the Hexi Corridor.

2. The second is the middle road. Strong cold air from Lake Baikal in Siberia and Mongolia passes through Inner Mongolia Autonomous Region of China, enters the north of China and reaches the southeast coastal area.

The third road is East Road. Cold air flows south from northeast Siberia, sometimes through eastern China, sometimes through the Sea of Japan and the Korean Peninsula, and invades the eastern coast of China. The main force of the cold wave going south from this route is eastward, which is generally not very strong and the frequency will not be too much.

Extended data:

Cold waves also have beneficial effects. The research and analysis of geographers show that the cold wave contributes to the heat exchange on the earth's surface. With the increase of latitude, the energy received by the earth from solar radiation gradually weakened, so the earth formed tropical, temperate and cold zones. The cold wave injects a lot of cold air into tropical areas, which makes large-scale heat exchange on the ground, which is very helpful to maintain the ecological balance of nature and maintain the lush species.

Meteorologists believe that the cold wave is the guarantee of good weather. For example, China is affected by the monsoon, and the winter climate is dry, which is a dry season. However, whenever the cold wave invades the south, it will often bring a wide range of rain and snow weather, alleviate the winter drought and benefit crops.

Why can the agricultural proverb "Xue Ruizhao has a good year" be circulated among the people for generations? This is because snow water has a high nitrogen content, which is more than five times that of ordinary water, and can greatly increase the nitrogen in the soil. Snow water can also accelerate the decomposition of soil organic matter, thus increasing the organic fertilizer in the soil. The heavy snow covered the overwintering crops and played the role of a quilt, keeping out the cold and keeping warm.

There is a saying that "winter is not cold, and the coming year is not abundant", which also has its scientific truth. Experts in crop pest control believe that the low temperature brought by the cold wave is the most effective natural "insecticide" at present, which can kill a large number of pests and germs lurking in the soil for the winter, or inhibit their reproduction and reduce pests and diseases in the coming year. According to the survey data of agricultural technology stations around the country, pesticides can be saved by more than 60% in the year of heavy snow and winter closure.