Cold weather phenomena caused by cold waves have become more frequent and powerful in recent years, which is closely related to global warming. Global warming has led to an increase in temperatures in the Arctic, which in turn has affected the intensity of the westerly jet stream. The westerly jet stream is a strong circle of westerly winds that surrounds the North Pole and acts as a restrain of cold air. However, global warming has caused the Arctic region to warm faster than other regions, resulting in a weakening of the difference between cold and warm, weakening the westerly jet stream, weakening the polar vortex**, and increasing the ability of cold air to move south. As a result, cold spells are more frequent and the cold they bring is more severe.
In addition, the power of cold spells is also related to other climatic factors. Recently, the temperature in China has fluctuated greatly, both in the early stage and in the later period. This fluctuation of warm and cold has something to do with El Niño. Although the winter in China is generally warm under the background of El Niño, the periodic cold air activities are frequent, which makes the temperature fluctuate significantly. In addition, the Arctic vortex** and the disturbance of the mid- and high-latitude westerly wind belt will also affect the power of the cold wave. This year's cold wave, the Arctic vortex was a double center in mid-December**, coupled with the strengthening of the Siberian high pressure, which caused the temperature in most parts of China to plummet.
The impact of the cold wave on China is mainly manifested in temperature and precipitation. The cold air brought by the cold wave caused the temperature to plummet, and in some areas it was even lower than the same period in history. During the cold wave, the temperature was more than 5 lower than that of the same period in normal years, and in some areas it was even lower than 7. It is expected that during the post-winter period, the temperature in the central and eastern parts of China will be close to the same period of the year, but the cold and warm fluctuations are obvious, and the temperature fluctuations may be experienced again. In addition, the cold wave process has also brought a wide range of precipitation to China, resulting in weather phenomena such as rain, snow and ice.
In the face of cold weather, the public should take some measures to protect themselves from the cold and keep warm. First of all, pay attention to keeping warm, wear thick clothing, and try to avoid prolonged exposure to the cold. Secondly, it is necessary to strengthen protection, close doors and windows in time, avoid cold air infiltrating into the room, pay attention to electricity safety, and avoid using unsafe heating equipment. In addition, it is also necessary to take precautions and pay attention to the icy conditions of the roads to avoid traffic accidents.
Although global warming has led to warming of the Arctic and weakening of the westerly jet stream, it cannot simply be assumed that global warming will lead to frequent cold air activity in winter. The frequency of cold air activity is also influenced by other meteorological factors. For example, the strength of the East Asian winter monsoon and the location and intensity of the subtropical high in the western Pacific will all have an impact on cold air activity.
In addition, the complexity of the global climate system makes it difficult to perform cold air activities. Although we can analyze the development trend of cold air activity through observations, models and other means, there is still some uncertainty about the specific time and intensity.
Therefore, the reasons for the high cold air activity are multifaceted, both related to climatic factors such as global warming and interactions with other meteorological factors. In order to better understand and ** the trends in cold air activity, further research and exploration of the complexity of the climate system are needed.