Why is the weather so unusually cold this year? Who knows what reason not?

This year is the anomaly.

This period of time belongs to the cold spring. So there will be unusually cold weather.

Doomsday? Hehe, just kidding....

It is estimated that it was caused by the ravages and destruction of nature by humans....

Now there are many natural disasters, mainly because the earth is overexploited, and the tantrum is lost...

1. La Niña phenomenon: When La Niña occurs, the longitudinal degree of the Eurasian middle and high latitude circulation is relatively large, and the cold air activity is also strong, and the temperature in most parts of central and eastern China is prone to be low.

2. Less Arctic sea ice: The lack of Arctic sea ice is conducive to the strong high-pressure ridge of the Ural Mountains in winter, the strong winter monsoon in East Asia, and the temperature in most of the central and eastern parts of China is likely to be lower than that of the same period in normal years.

At that time, scientists observed an El Niño phenomenon that lasted for more than five months – the previous winter was a "warm winter" and was largely influenced by El Niño. And throughout the summer of 2020, the meteorological events (including a series of meteorological disaster events) that occurred in Eurasia and the Americas were more or less related to it.

La Niña often follows El Niño. In early October 2020, the Japan Meteorological Agency announced that they had observed that La Niña had formed and was likely to run through the entire winter in the Northern Hemisphere.

La Niña, which means "little girl" in Spanish, is also known as an anti-El Niño phenomenon, which refers to a phenomenon that occurs in the eastern and central equatorial Pacific Ocean, where the surface temperature of the sea is below and above the climatic average for more than 6 months. La Niña, which is a sign of hurricanes, torrential rains and extreme cold, can cause severe anomalies in the global climate, along with El Niño.

The effects of La Niña in general include unusually dry areas of the southwestern United States and the west coast of South America, unusually high levels of precipitation in Southeast Asia such as Australia, Indonesia, Malaysia and the Philippines, and unusually cold in Northeast Asia such as the west and southeast coasts of Africa, Japan and the Korean Peninsula.

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.

Since the climate is influenced by the continents, the oceans are very significant. In winter, the northerly wind blowing from the mainland to the ocean, coupled with the strong cold air activity on the ground, turns into early spring, and the temperature changes greatly, so pay attention to keeping warm.

The change in temperature is mainly affected by the height of the sun at noon and the length of day and night.

The change of winter and summer is caused by the existence of the yellow-red intersection angle, and the change of the two elements at different times during the earth's revolution. Different latitudes, even in the same hemisphere, with different heights of the sun at the same time, the temperature is of course different. But in winter, the temperature in our country is much lower than that of Western Europe at the same latitude, mainly due to:

1. Differences between land and sea. The temperature difference between winter and summer is low in the ocean due to the slow heat absorption and heat release.

2. Siberia, which is covered by ice and snow (reflecting sunlight and reducing ground absorption), forms an extremely low temperature zone, and the "cold air" blown by it seriously affects the winter temperature in China. We can see that the temperature has warmed up after the cold air.

The direct cause of the colder weather is the reduction in sunshine. From the summer solstice, the sun moves towards the southern hemisphere, and by the winter solstice, the sun is on the Tropic of Capricorn in the southern hemisphere. For the Northern Hemisphere, the sun is oblique, and the amount of solar energy in the Northern Hemisphere is greatly reduced, so it will get colder and colder, and for the areas where we live, because the heat from the sun is less, we will not be able to resist the cold air from the Arctic region to the south, so it will be very cold.

Hello friends! The first reason is that we are in a La Niña state this year, that is, the sea surface temperature in the eastern equatorial Pacific 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 1Warm 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.

Because the point of direct sunlight moves! The summer sun in the Northern Hemisphere shines directly on the Tropic of Capricorn, which is closest to us, so it's hot. In autumn, the point of direct exposure of the winter sun moves southward across the equator, farthest from us.

At this time, under the action of the geostrophic and monsoon, cold air will blow from Siberia in the north, so it will snow and cool down.

This question begins with the rotation of the earth.