Why is it so cold in winter?

The cold air activity on the earth is the direct cause of the cold weather. At the same time, because the earth revolves around the sun, when the direct point of the sun in the northern hemisphere moves south, these places in the northern hemisphere will get cold. Similarly, in the southern hemisphere of the earth, when the direct point of the sun moves northward, these places in the southern hemisphere will get cold. It is not the reason why the earth revolves to perihelion and aphelion. In the northern hemisphere, Eurasia is greatly influenced by the warm westerly winds of the North Atlantic in winter. When the warm west wind in the North Atlantic is stable, it can prevent the polar cold air from going south, thus weakening the cold wave. But this year's La Nina phenomenon broke the stability of the warm west wind in the North Atlantic. La Nina phenomenon is that the southeast trade winds blow away the sea water heated by the sun near the equator, which makes the lower cold sea water turn up and the pressure increase, which makes the subtropical high in the northern hemisphere stronger and prevents the warm westerly wind from coming to Eurasia, thus helping the polar cold air to continue southward. It is cold in winter because the decrease of the sun's altitude angle reduces the amount of sunlight exposure and shortens the exposure time.

1, the key factor of the earth's cooling in winter lies in the inclination of the earth's rotation axis. In the image, when the earth welcomes the next winter, the angle of the earth is inclined. When the sun shines on this tilted planet, most of the sunlight will be reflected away, and a lot of sunlight will naturally lower the temperature.

2. In China, located in the east of Asia, the northwest wind from Mongolia and Siberia prevails in winter. The northwest wind originated in the hinterland of Asia, which is cold and dry, and the wind force is greater than the summer monsoon, resulting in cold winter in most parts of China.

Related content explanation:

In winter, some people feel very cold, while others are not so cold. This is because of physical differences. People who often feel very cold:

1, poor blood circulation and reflux ability.

2. Insufficient yang in the body.

3, qi and blood spleen and stomach weakness.

So in winter, in addition to wearing more clothes to keep warm and cold, avoid staring at it at close range. Pay attention to regulating the spleen and stomach, eat more positive food and keep fit.