What harm does the cold wave bring?
Performance of harm caused by cold wave
1, gale
When the cold wave comes, there will usually be windy weather, mostly in the north and northeast of China, usually above level 5. The appearance of cold wave and windy weather will have a certain impact on people's travel. At the same time, windy and cool weather is easy to cause colds and blow down surrounding buildings. Therefore, for the sake of safety, outdoor sports are not recommended in windy weather.
2. Blizzard
Cold wave will bring snowy weather. If it snows heavily, the road will be blocked, and then the telephone poles may be crushed, resulting in power failure. Therefore, we must take precautions and deal with the inconvenience caused by heavy snow in real time.
Step 3 freeze injury
The cold wave will make the temperature very low, which will seriously cause freezing damage to plants and directly lead to plant death. Therefore, we must do a good job in preventing the sudden drop of temperature, so as to resist the freezing damage caused by the cold wave.
Cold wave warning is issued according to the following standards:
(1) orange warning: It is estimated that in the next 48 hours, the average or minimum temperature in most areas of two or more provinces (autonomous regions and municipalities) will drop by more than 16℃, accompanied by strong winds of magnitude 6 or above, and the average or minimum temperature in the Yangtze River basin and more than half of its north will drop by more than 12℃, and the middle and lower reaches of the Yangtze River (Jianghuai area in spring and autumn)
(2) Yellow warning: It is predicted that in the next 48 hours, the average or minimum temperature in most areas of two or more provinces (autonomous regions and municipalities) will drop by more than 12℃, accompanied by strong winds of magnitude 5 or above, the average or minimum temperature in the Yangtze River basin and more than half of its north will drop by more than 10℃, and the minimum temperature in the middle and lower reaches of the Yangtze River (Jianghuai area in spring and autumn) will drop to 4℃ in winter.
(3) Blue warning: It is predicted that in the next 48 hours, the average or minimum temperature in most areas of two or more provinces (autonomous regions and municipalities) will drop by more than 10℃, accompanied by strong winds of magnitude 5 or above, the average or minimum temperature in the Yangtze River basin and more than half of its north will drop by more than 8℃, and the minimum temperature in the middle and lower reaches of the Yangtze River (spring and autumn in Jianghuai area) will drop below 4℃ in winter.
The difference between cold air, cold wave and cold current
Cold air —— According to the eight new national meteorological standards issued by China Meteorological Bureau, the newly issued cold air grade standard indicates that cold air refers to the air that causes the temperature of the passing place to drop. The division principle is the range of daily minimum temperature drop and the daily minimum temperature value in the area affected by cold air in a certain period of time. The cold air level is divided into five levels. Cold air can be divided into five grades: weak cold air, moderate intensity cold air, strong cold air, strong cold air and cold wave.
Cold wave-cold wave is a common disastrous weather in China, which occurs frequently and has a wide range of activities. Cold wave, as its name implies, is a form of air (cold air) flowing like tide. But not all cold air attacks are called cold waves. Generally, after cold air attacks a place, if the temperature in those places can drop by more than 10 degrees Celsius in one day (24 hours), and the lowest temperature in that day is below 5 degrees Celsius, we call this cold air a cold wave. However, due to the influence of geographical environment and climatic conditions, the cold wave standards are also different. In the national standard of cold air grade in China formulated by the Central Meteorological Observatory in 2006, the standard of cold wave is: after cold air passes through a certain area, the temperature drops above 8℃ within 24 hours, and the minimum temperature drops below 4℃; Or the temperature drops 10℃ or above within 48 hours, and the minimum temperature drops below 4℃; Or within 72 hours, the temperature drops continuously by more than 65438 02℃, and the lowest temperature is below 4℃. A cold wave is usually accompanied by a wide range of windy weather. After the gale, severe cold will follow, which will bring harm to agriculture, fishery, transportation, architecture, flowers and even human health. Therefore, the meteorological observatory should issue a cold wave warning before the arrival of the cold wave.
Cold current-cold current refers to the large-scale flow of seawater from high latitude sea area to low latitude sea area, which belongs to the category of ocean current (seawater) flow. Although the cold current has a certain impact on the climate in coastal areas, it is not a cold current after all. When a cold wave or cold air goes south, people will feel that the cold wave invades their skin. People usually mistake the cold wave for the cold wave, which is actually a habitual language error.