Why does the cold air come from Siberia? Does anyone know why?

I believe everyone has studied geography, but as for how cold air is formed, I believe everyone has basically returned it to the teacher after learning it. The cold air initially comes from the Arctic Ocean and then intensifies through Siberia. Here we need to first understand the characteristics of places like the Arctic and Antarctic. The Antarctic and the North Pole are also called the polar regions. The sun rarely appears in the polar regions and is difficult to cover. Therefore, the near-surface layer absorbs very weak heat from the sun during the day, but radiates a large amount of heat to space at night. The near-surface layer As the atmosphere continues to cool down, the temperature gets lower and lower, and more and more cold air accumulates together.

1. Cold air and hot air

The coldness and heat of the air are defined by the difference in the horizontal direction of the air temperature. The air located in the low temperature area is called cold air, and the polar and Siberia, which is close to the pole, has relatively low temperatures and naturally has more cold air. The question is why does the flow of cold air always flow from north to south? Why doesn't the hot air from the south flow to the north and bring temperatures to the north (good hope), but the cold air from Siberia always flows to the south (so sad)? This is due to the flow of cold air - wind.

2. Hot poles generate wind

Scientific experiments have found that cold air is heavier than hot air. Cold air will flow downward, while hot air will flow upward. Think of our great ancestors This has long been used to achieve high-altitude flight - a hot air balloon. I believe everyone has encountered such a scene: the weather suddenly becomes extremely hot for several consecutive days in summer, and then one day it blows with strong winds and starts to rain. This is the so-called hot wind. The reason for this phenomenon is also related to cold air and hot air. The temperature in our area has become higher than usual, and the natural air pressure has also become lower. This change in air pressure exceeds people's ability to feel air pressure under normal weather, so it gives people a feeling of stuffiness.

At the same time, the hot air rises, and the cold air in other areas begins to "fill" the rising hot air in this area. That is, the warm air expands and becomes lighter and then rises, while the cold air cools and becomes heavier and then falls. In this way, the cold and warm air alternate. As mentioned earlier, the difference between low latitudes and high latitudes in the south and north is that in the former, the sunshine time is long and the heat absorbed by the stratum is high, while in the latter, the heat absorbed by the stratum is less and the temperature is low. This altitude The difference between latitudes creates a pressure difference, causing the air to move horizontally, and the wind blows along the direction of the horizontal pressure gradient, that is, blowing perpendicular to the isobars from cold high pressure to warm low pressure. The earth is rotating, and the force that deflects the horizontal motion of the air is called the geostrophic deflection force.

This force deflects the airflow in the northern and southern hemispheres to the right. Therefore, in addition to the pressure gradient force, the movement of the earth's atmosphere is also affected by the geostrophic deflection. The real movement of the atmosphere is the result of the combined influence of these two forces. Of course, the wind is not only controlled by these two forces, but is also affected to a large extent by the ocean and terrain. Mountain passes and straits can change the direction of air flow and increase the wind speed, while friction in hills and mountains increases the wind speed. The wind speed of isolated mountain peaks increases due to their high altitude.

3. Cold wave vs. cold wave

Here is a word that is often used incorrectly in daily life - cold wave. Every time the weather forecast says that cold air will move southward, it will cause widespread cooling in our country. We habitually call this cold air a "cold wave", which is actually incorrect. This phenomenon should be called a cold wave. Cold wave and cold wave are two different concepts. Generally, after the arrival of cold air, the local temperature drops by more than 10°C in a day, and the lowest temperature of that day is below 5°C. This cold air is called a cold wave. Of course, in practice there is no such strict definition.

Cold currents are part of ocean currents (also called ocean currents) in the world's oceans. Ocean currents refer to the slow and regular flow of water on the surface of the ocean in a certain direction at a huge scale and at a relatively stable speed. When the temperature of the sea water is lower than the temperature of the sea water passing through the sea area, the ocean current is called a cold current, and vice versa, it is a warm current. Cold air means that the poles are moving closer to the equator. In layman's terms, it means that the equator is too hot. When the hot wind goes up, the cold wind blows over. Cold places blow toward warmer places. China is in the northern hemisphere, and the Antarctic wind cannot reach the equator. It can only hit the North Pole. The North Pole blows to Siberia, and Siberia blows to China. This question is so strange. If the cold air does not blow into the country from that corner, it is completely different. Could it be from Hainan Island?

Because the continent cools faster than the ocean in winter, the lower the temperature, the higher the air pressure, which creates conditions for the formation of the Mongolia-Siberia high pressure area, which is one of the high pressure centers in the northern hemisphere in winter. Air flows from high pressure areas to low pressure areas, and this pressure difference promotes the flow of cold air. As someone who has spent time in Siberia, I will just talk about my own experience. I will not explain it in terms of meteorological and geological principles. I will search a lot of theories on the Internet. Russia is divided into 7 regions: Central District (capital Moscow), Northwest District, Southern District, Ural District, Volga District, Siberian District, and Far East District. Russia is a country that spans the Eurasian continent. The dividing point is the Ural Mountains. The west of the mountains belongs to the European region, and the east of the mountains belongs to the Asian region. Siberia belongs to the Asian region. It is also the region with the least population and the most backward economy. (The southern region has There was a war before, so the infrastructure was very backward, which can be seen from the venue of the Sochi Winter Olympics.

The Far East is also very backward. Many Chinese people doing business have to think of the eternal pain: Vladivostok. ) Local residents in Siberia told me: Moscow and Petersburg are completely different Russias, two different worlds from ours. When he said this, the young man's eyes showed his helplessness and disappointment at Siberia's backwardness. This is a pretty good apartment building in a city in Siberia. Many locals live in older and dilapidated houses, as well as wooden houses.

In winter in the northern hemisphere, the pressure belt moves southward. The pressure belt is cut off due to the different thermal properties of the oceanic continent (the seawater temperature is higher than that of the continent). A cold high pressure is formed on the land, namely the Mongolian Siberian High (located at high latitudes inland, continental). The climate is strong, drought, little rain, and severe cold, which should be a subarctic coniferous forest climate). Since the ocean is a low-pressure system, high pressure points toward low pressure, forming an anticyclone. Cold anticyclones are cold waves. However, it is also possible that frontal activity caused the cold wave. Cold air from Siberia moves southward and actively moves toward warm air, causing rainfall and strong winds. After the front passes, the weather clears, the air pressure increases, and the temperature decreases. Also, the abnormal temperature this year is due to the cold wave not coming from Siberia, but from the Arctic region. It is said that there are hurricanes and other things in the polar region.