However, he said that since the current situation of global warming, how much La Nina can reduce the temperature in China, what exactly will happen this winter, further observation is needed, and we should pay close attention to the early warning of numerical weather forecast.
Although La Nina occurred in the tropical Middle East and Pacific, Zheng Fei said, but its impact has spread to the whole world, and China's autumn and winter climate will also be largely affected by it. When it occurs, it will lead to drought in some parts of South America, which will cause significant heavy rainfall in Southeast Asia, and at the same time lead to a colder winter temperature in China. Zheng Fei said, for example, the extreme freezing disaster in 2008 was related to La Nina.
"The largest El Niño event since the 21st century has erupted at the beginning of this year, followed by the current tropical Middle East Pacific cold phenomenon. From May and June this year, the cold sea temperature has gradually developed and maintained." Zheng Fei said. At present, many countries believe that the La Nina phenomenon is more likely this year. Columbia University in the United States gathered 20 climate model forecasts that the end of this year will continue to be in the state of La Nina.
With the first snowfall in Beijing, the temperature plummeted. There are rumors that with the arrival of the "Virgin" La Nina, this year may be "frozen". So, where is this "Virgin" sacred? Will it be cold this winter?
"La Niña is El Niño's" sister "and appears alternately with it." Zheng Fei, Institute of Atmospheric Physics, Chinese Academy of Sciences, explained at the publication salon of "Medical Media Benefit" scientific papers recently. El Niño is a large-scale warming phenomenon that occurs in the tropical Middle East and Pacific Ocean. It means "holy infant" in Spanish. And La Nina is its counter phenomenon, accompanied by the large area of cold water in the tropical Middle East Pacific, meaning "Virgin".
Zheng Fei said that the forecast provided by the Institute of Atmospheric Research to the National Climate Center and the National Marine Environment Forecasting Center in October this year also believed that there would be a 40% to 50% probability of a La Niña event after autumn, but its intensity would not be too great It is likely to be a weak event. "If the cold winter occurs, China's agriculture and forestry industries should take precautionary measures in advance, paying particular attention to the impact on the animal husbandry in the north."
"When the La Niña event occurs, the average winter temperature in China will be much lower than 0.5 degrees than usual, and the degree of coldness in the north will be more obvious." Zheng Fei said. 1954 was the lowest temperature in China affected by La Niña since 1950. The temperature in that year was about 2.5 ° C lower than usual. The average winter temperature in Hainan even dropped below zero.
It is reported that there have been 14 La Niña events in China since 1950, of which 11 winters can be defined as cold winters. When La Niña occurs, the chance of severe coldness in winter can reach 70% to 80%. On average, the north is colder than the south, and the northeast and northwest are more severe.
According to reports, generally speaking, if the average sea temperature in the equatorial Middle East and Pacific region continues to be colder than 0.5 ° C for 3 months, the tropical Pacific will be considered to have entered the La Nina state. However, only when the state lasts for more than 6 months will it be determined that a La Niña event has occurred.
"After the La Niña incident, there is often a tail, so after the La Niña incident at the end of this year, the tropical Middle East Pacific SST may remain cold for a long time in the next one or two years." Zheng Fei reminded.