What is the cold air flow in the Arctic Ocean?

Cold wave is a large-scale weather process, that is, the cold air in the north is large.

Large-scale invasion of China south will cause a wide range of sharp cooling, strong winds and rainy and snowy weather along the way, which generally occurs in late autumn, winter and early spring. According to the national standard of People's Republic of China (PRC).

According to the provisions of cold wave grade (GB/T2 1987-2008) and cold air grade (GB/T 20484-2006), single station cold wave is defined as the daily minimum at a certain place.

(or daily average) the temperature drops to ≥8℃ within 24 hours, or ≥ 10℃ within 48 hours, or ≥ 12℃ within 72 hours, and the daily minimum temperature in this place is ≤4℃.

Cold air activity. A regional cold wave refers to a cold wave, which is defined as a regional cold wave when more than 40% of the stations in the area have a cold wave.

The latest standards are: a cold air activity will reduce the temperature in the Yangtze River basin and its northern area by more than 10℃ within 48 hours, the lowest temperature in the middle and lower reaches of the Yangtze River will reach or be lower than 4℃, there will be 5-7 winds in the land equivalent to three administrative regions, and 6-8 winds in the three coastal areas. Failure to meet this standard can only be called strong cold air or general cold air.