What are the characteristics of cold wave weather?

In the Arctic, due to the weak sunlight, the ground and the atmosphere get less heat, and it snows all year round.

In winter, the direct sunlight passes through the equator and reaches the southern hemisphere. The arctic region is colder and wider, and the temperature is generally below MINUS 40℃-50℃. Large-scale cold air masses gather to a certain extent, and under the action of suitable high-altitude circulation, they will invade southward on a large scale, forming cold wave weather.

Because the temperature in the Arctic and Siberia is very low, the density of the atmosphere will increase greatly, and the air will continue to shrink and sink, increasing the pressure. This will form a strong, deep and broad cold and high-pressure air mass. When this cold and high-pressure force increases to a certain extent, it will flood into China like a tide that has burst its banks. This is the cold wave.

Every time a cold wave breaks out, the cold air in Siberia will decrease and the air pressure will also decrease. But after a while, the cold air gathered again and piled up, gestating a new cold wave outbreak.

According to the degree of strength, the cold air in China is divided into five grades: weak cold air, medium-intensity cold air, strong cold air, strong cold air and cold wave. The cold air that makes the daily minimum temperature of a place drop more than or equal to 8℃ within 24 hours, or 10℃ within 48 hours, or 12℃ within 72 hours, and makes the daily minimum temperature of the place drop below 4℃ is called a cold wave. The cold wave is also the highest level of cold air.

Second, what are the characteristics of cold wave weather?

Cold wave is a large-scale weather process, which will cause a wide range of severe cooling, strong winds and snowfall along the way. Disasters caused by cold wave, such as gale, frost, snowstorm, etc., have great influence on agriculture, transportation, electricity, navigation and people's health.

Cold wave gale is windy weather caused by cold wave weather. Cold wave and strong wind involve a wide range. Inner Mongolia, Gansu, Ningxia, northwestern Shaanxi, northwestern Shanxi, Hebei, northern Henan, Heilongjiang, Jilin and Liaoning in the north of China are all areas with frequent cold waves and strong winds. Cold waves and strong winds may also occur from the south of Huaihe River to the middle of South China Sea. Cold waves and strong winds are mainly northerly winds, and the wind force is generally 5~6. When the cold air is strong or the ground low pressure develops strongly, the wind force can reach 7~8, and the instantaneous wind force will be even greater.

Cold waves occur in winter and spring. There are still some differences between cold wave weather in spring and cold wave weather in winter. For example, the strong cold wave weather in the middle and late June this year, 65438+ 10 occurred in the middle of winter, when the base temperature was relatively low, and the minimum temperature dropped significantly during the cold wave. Spring is a season of alternating cold and warm. Controlled by warm and humid air flow, the temperature drops greatly after the arrival of the cold wave, especially the highest temperature drops greatly, but the lowest temperature drops slightly.