Isn't it global warming? Why is our winter getting colder and colder?
This winter can be said to have saved one's dignity on the ground. Multiple rounds of large-scale cold air made the whole country cry out.
In previous years, even if you are greedy for heating and air conditioning, you will go out to feel the romance of snowflakes, but now everyone is "held" by the cold.
The more "chilling" news is that from the 10th to the 12th of this month, there will be a blast of cold air, which is really the rhythm of being frozen into a dog!
Under the great stimulus of the cold, some people will think, isn’t the world warming, why is the weather getting colder and colder? Is global warming bluffing?
Actually, the earth is getting hotter and hotter, and the winter we are experiencing is indeed colder than before, but the two are not contradictory.
The fact of global warming
Humans were not interested in temperature in ancient times. The real temperature records appeared in modern history, but the early records were limited to technical reasons and the accuracy was not high.
It was not until 1860 that more reliable temperature instruments appeared in the world, and since 1889, measuring instruments have basically been widely used.
In 1979, humans began to use meteorological satellites to measure the temperature. The temperature can be reflected by the thermal radiation data measured by the remote sensing instrument carried by the satellite, and the accuracy is very high.
Since 1880, the average global surface temperature has increased at a rate of 0.07°C per decade, and after 1981, this rate has increased more than twice.
In the past 100 years, the average surface temperature has risen by more than 1℃, and between 1906 and 2005, the global average temperature of the atmosphere close to the ground has risen by 0.74℃.
Even though these values seem insignificant, the impact it brings is indeed huge: rising sea levels, changes in precipitation, expansion of deserts in subtropical regions, etc.
According to the prediction of climate model, in this century, the global surface temperature may further rise by 0.3-4.8℃, and the consequences will be more serious at that time.
The difference between weather and climate
The global temperature is indeed rising, so why is the weather getting colder and colder? In fact, this question obviously confuses the weather with the climate.
Weather is the state of the atmosphere in a short period of time, and climate is the way the atmosphere behaves in a long period of time. For example, wind and sunshine refer to weather, and four seasons such as spring refer to climate.
We were shivering and shivering in the cold in the winter, but in other places, heat waves hit and people were sweating like rain. This shows that the weather in different places is different.
And after counting the hot and cold conditions around the world for a long time, you will find that the high temperature weather is actually more and more frequent.
2014-2019 is called the hottest five years on the earth, and it is very rare in the history of the earth to reach the highest temperature of the earth for five consecutive years, which also reflects the fact that the earth is warming from the side.
Therefore, it is illogical to refute global warming with our own cold. No matter how the world warms, the four seasons of the earth still exist.
Global warming makes winter colder
However, the opposite fact that we take for granted that global warming should also warm the weather is that global warming will make winters colder. What we are talking about later is the northern hemisphere
Due to factors such as the thinness of the earth’s atmosphere, the “tilt” of the earth itself, and the coverage of clouds, there is a huge temperature difference between the equator and the poles.
This temperature difference is the smallest in summer, because the Arctic region has experienced almost 24 hours of continuous sunlight, while the situation in winter is the opposite.
The huge temperature difference will make every pole have a continuous large-scale low pressure zone, which rotates from west to east in a cyclonic manner.
Picture: stable polar vortex and broken polar vortex
These two regions are called polar vortices polar vortices for short. They each form a few kilometers in the atmosphere and extend up to the stratosphere.
Usually, due to the huge temperature and air pressure difference, the polar vortex will stabilize in a proper position throughout the year without breaking or running around.
And when the Arctic polar vortex weakens, it will cause a lot of cold air to begin to flow, thanks to the huge air pressure, they are almost unstoppable.
When cold air mixes with warm mid-latitude air and continues southward, Eurasia and North America continents may experience unprecedented cold currents.
Picture: surface temperature
Then what does this have to do with global warming?
The polar vortex generally does not rupture and flow. It will rupture only when the temperature of the stratosphere rises. The problem lies in the temperature change of the stratosphere.
Global warming will cause the temperature of the land to rise, and the North American continent of Eurasia is large, which can transfer a lot of heat to the stratosphere over the North Pole.
Therefore, global warming caused the temperature of the stratosphere above the North Pole to rise, which in turn caused the rupture and flow of the Arctic vortex, and finally caused the extreme cold weather.
On the other hand, the jet airflow is also positive for the stability of the polar vortex. It is like a barrier that will block the flow of the polar vortex.
The jet stream is the result of the interaction of warm air from the equator and cold air from the North Pole. Guided by the rotation of the earth, this stream moves from west to east at a speed of more than 300 kilometers per hour.
Picture: Polar vortex breaks through jet stream circle
The temperature difference between north and south is the largest in winter, and the density difference between cold air and warm air is also the largest, so the jet airflow is the strongest, and it has the strongest blocking effect on the Arctic vortex.
But global warming causes the temperature in the Arctic to rise, which reduces the density difference between warm and cold air and weakens the power of the jet airflow. It has always been in a uniform ring shape and it begins to become distorted.
Once the blocking effect of the jet stream is reduced, the polar vortex will more easily rush out of the "environmental circle", all the way south, bringing a cold current.
Global warming is not a hoax, but a real thing happening on the earth. As the earth continues to warm, more abnormal weather will appear in life.
And to change this situation, at least several hundred years.
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