The greenhouse effect slows down the speed of ocean currents, and the winter in Europe is getting colder and colder.
165438+1At the end of October, European countries were hit by snowstorms and cold currents, from Britain to Poland, from Germany to Greece, all of which were affected by sudden cooling to varying degrees. Heavy snow caused traffic chaos, power outages, schools closed, and some people froze to death in the cold ... Why is it getting colder and colder in winter in Europe?
It is particularly cold in Europe this winter.
In North Rhine-westfalen, the most populous German state, the snowfall was as high as 20 cm, and the airport was forced to close. Airport spokesman Tollsten Hillman told reporters: "I have worked in this airport for 1 1 year, and I don't remember anything similar happening in the past." In France, heavy snow caused some roads to be blocked, and traffic jams in some areas were about 50 kilometers long. The cold caused three Frenchmen to freeze to death in the streets. At present, the government has declared a state of second alert. The British authorities also warned the public to prepare for the coldest winter in decades.
In fact, cold weather has become a "routine" for Europeans. In March this year, the temperature in Paris, Berlin, Vienna and other cities dropped by more than 5 degrees compared with the same period last year.
It's cold for a reason.
Professor Steffen Ramsdorf of the German Institute for Climate Change told the reporter that the winter temperature in European cities can generally be 9 degrees Celsius-18 degrees Celsius higher than that in other parts of the same latitude, which is due to the warm current in the North Atlantic. It's getting colder and colder in Europe in winter because of the circulation problems of the Atlantic Ocean current.
The picture on the right shows the circulation diagram of the Atlantic ocean current. As the picture shows, in the middle of the Atlantic Ocean, an ocean current will move northward in a clockwise circulation. When this tributary flows to the sea near Norway, its warm seawater has cooled. Because the temperature is too low, this ocean current begins to sink, then flows back to the south of the equator and is heated again, thus pushing the warm ocean current to the north at high latitudes. Therefore, this ocean current will continue to bring heat to the North Atlantic region, making the climate conditions in Central and Western Europe mild.
But now, scientists have found that the Atlantic ocean current that brings warmth to Europe in winter is slowing down. 165438+1On October 30th, Harry Braddon, a scientist from ocean centre, Southampton, England, published his research results in Science magazine. In 2004, a research team led by him conducted a sampling survey between Bahamas and Canary Islands along 25 degrees north latitude to detect the salinity and density of water. Compared with the records of 1957, 198 1, 1992 and 1998, it is found that the backflow speed of deep-sea cold water has obviously decreased since 1957, especially since 65438+.
Global warming is the culprit.
The slowdown of the Atlantic ocean current means that the temperature of the North Atlantic and nearby continental plates has dropped. This is the reason why winter in Europe is getting colder and colder. What is the reason for the slowdown of the North Atlantic warm current?
According to scientists from the Hadley Center of the British Meteorological Office, the reason why the Atlantic Ocean current has changed is that the greenhouse effect caused by human beings has increased the amount of fresh water flowing to the Atlantic Ocean. Global warming has accelerated the melting of Greenland ice sheet and Arctic ice and snow, and a large amount of fresh water has been injected into the North Atlantic. The sinking speed of water is related to the salt content and density. The higher the density of salt, the faster the water sinks. Fresh water is lighter and less dense than salty sea water, and even cold water will not sink too deep. Therefore, the sinking speed of the melting ice water in the North Atlantic drops sharply, and a large amount of fresh water accumulates on the ocean surface, resulting in insufficient power to move northward, slowing down the speed, and even finally stopping.
Will it get cold in winter in Europe?
According to the ancient meteorological records, the temperature in the north has dropped by 10 degrees in several decades due to the slowing or stopping of ocean currents. In the past ice age, the climate changed suddenly and violently because the circulation system of the Atlantic Ocean no longer operated. Scientists, including Harry Bladen, predict that if the ocean current slows down, the winter temperature in Britain will drop by 2 degrees in the next 10 year. If the ocean current stops completely, the average temperature in northern Europe and western Europe may drop by 6 degrees or even 10 degree in the next 20 years, which is a very obvious change and will make winter extremely cold.
Scientists say that global warming does not mean that the temperature has been rising. In Europe, global warming will be manifested as getting hotter in summer and colder in winter. Some scientists believe that the earth is approaching the end of the solar warming cycle, and global warming will eventually make the earth enter the next cold period. It can be predicted that if global warming continues, the temperature in Europe will drop further, and the temperature in warm northwest Europe will be as cold as Siberia now, and this process will last for a long time.
Kuedefis, an oceanographer at the University of Hamburg, said that this phenomenon shows that "we are really changing the climate and urgently need to formulate policies to protect the environment".
greenhouse effect
The surface temperature of Venus is as high as 447℃. Why is it so hot?
The greenhouse effect refers to the heat insulation effect caused by the lack of heat exchange with the outside world in a closed space that transmits sunlight. The greenhouse effect on Venus is staggering, because the atmospheric density of Venus is 100 times that of the earth's atmosphere, and more than 97% of the atmosphere is "heat preservation gas"-carbon dioxide; At the same time, there is a thick layer of concentrated sulfuric acid in the atmosphere of Venus, which is 20 ~ 30 kilometers thick. Carbon dioxide and thick clouds only allow sunlight to pass through, but do not allow heat to radiate into space through clouds. The enclosed solar radiation makes the surface of Venus hotter and hotter. The greenhouse effect makes the surface temperature of Venus as high as 465-485℃, which basically has no distinction between regions, seasons and days and nights. This also leads to a very high air pressure on Venus, about 90 times that of the Earth.