Why is it so cold and why is it so cold

It's been nine days, and it's freezing cold, the weather is not cold, the climate is not normal, and the earth is not a disaster.

There should be two reasons The first reason is that we are in a La Niña state this year, that is, the sea surface temperature in the eastern Pacific region of the equator is lower than normal and below the negative degree, and the impact of this phenomenon on China's climate is very obvious. It's going to have a cold winter, so we can see that this cold winter is coming this year. The second reason is that the two conditions that must be met for snow or rain are 1

Warm and humid air currents from the tropics. 2.There is cold air from the alpine regions.

Areas of winter snowfall (the same is true for areas of summer rainfall) are located near fronts, i.e. at the junction of warm and cold air masses. This position is not fixed, it is determined by the strength of the forces of the two natures. The cold air mass is weak, and the front and precipitation area are higher latitudes, and the cold air mass is stronger, and the front and precipitation areas are lower latitudes.

The land cold high that affects China in winter is the Asian high (also known as the Mongolian and Siberian high pressure) centered in Mongolia and Siberia, and its sphere of influence is very large, which has a great impact on the weather in China, especially in the northern region. The cold air that affected our country in the early part of midwinter this year is relatively weak, and the number of times is not much, even with the cooperation of warm and humid airflow, it is not easy to snow without cold air. However, since 2008, the Asian high pressure is very active, and the cold air mass continues to form southward to affect our country, resulting in a wide range of windy cooling weather, but because the warm air mass in the south this year is also very active, a large number of warm and humid air currents from the Pacific Ocean and the Indian Ocean frequently visit the southern region, when the strong cold air mass from Siberia, Mongolia quickly moves south to the southern region, and meets with the warm and humid air mass, the cold, warm two just combined.

Affected by the combination of these two airflows, there has been a lot of rain and snow in recent times, especially in the Yangtze River basin, and the weather has been maintained at low temperatures for a long time. If there is only a strong cold air mass, and there is no large amount of water vapor provided by the warm and humid air mass, there will only be strong winds and cooling weather in the south; If there is only a large amount of water vapor provided by the warm and humid air mass, and no cold air mass is present, there is no catastrophic weather at all. And when both are in place, disaster strikes.

The heart is cold, and you can feel the cold even on a hot day

Because there is constantly cold air coming in.

Cold air activity on Earth is the direct cause of cooler weather.

At the same time, because the Earth revolves around the Sun, these parts of the Northern Hemisphere become cooler when the direct point of the Sun moves south. Also in the southern hemisphere of the Earth, these places in the southern hemisphere become cooler when the direct point of the sun moves north. It is not the reason why the Earth's revolution turns to perihelion and aphelion.

The Eurasian continent in the Northern Hemisphere is greatly affected by the warm westerly winds of the North Atlantic in winter, and when the warm westerly winds of the North Atlantic are stable, they can block the southward movement of the polar cold air, thereby weakening the cold wave. But this year's La Niña event has upset the stability of the warm westerly winds in the North Atlantic. Hunger and repentance.

La Niña is a phenomenon in which the southeast trade wind blows away the hot sea water near the equator, causing the upper core of the lower cold sea to tease and increase the air pressure, making the subtropical high pressure in the northern hemisphere stronger, preventing the warm westerly wind from the North Atlantic from coming to the Eurasian continent, so as to facilitate the continuous southward movement of cold air from the polar regions.