Is 2022 a warm winter or a cold winter? Will it be colder this winter?
Keywords: Is 2022 a warm winter or a cold winter? Will it be colder this winter?
It's too long to read the version: this year is the year of La Nina, and La Nina phenomenon will lead to high SST in the northwest Pacific Ocean. There will be more typhoons in autumn and winter when there are fewer typhoons. Typhoon will attract cold air from the north to the south, so theoretically La Nina phenomenon will make our country colder in winter. La Nina event is only one of the important factors affecting the underlying surface forcing in autumn and winter climate in China, and the situation needs further monitoring and analysis this winter.
According to the new monitoring results of the National Climate Center, La Nina event develops slowly after the autumn and is expected to last until the winter of 2022/2023. This is the first "triple" La Nina phenomenon in 2 1 century. "Triple" means that this phenomenon lasted for three years and caused related disasters all over the world.
La Nina events have an important impact on regional climate anomalies in autumn and winter, such as autumn rain in West China, autumn drought in South China and autumn waterlogging in North China. Since autumn this year (from September 1 Sunday to September 9 10), China's climate has been warmer and drier, and La Nina event is one of the influencing factors. It is generally believed that La Nina often has a cold winter. Will it be colder this winter?
La Nina event develops slowly and is expected to last into winter.
La Nina event refers to the phenomenon that the sea surface temperature in the eastern and central equatorial Pacific Ocean continues to cool abnormally in a large range. After La Nina event, the global climate will have different degrees of abnormal characteristics.
The winter of 2020/202 1 was the beginning of this triple La Nina event, and this phenomenon also appeared in the winter of 202 1/2022, so 202 1 was called the Double La Nina Year. Today (65438+1October 1 1), the National Climate Center announced that the La Nina event developed slowly in autumn and is expected to last until the winter of 2022/2023, which will be the first "triple" La Nina phenomenon in 2 1 century.
Wei Ke, deputy director of the Monsoon System Research Center of the Institute of Atmospheric Physics, Chinese Academy of Sciences, previously introduced that La Nina events mainly affect the atmospheric circulation, which in turn affects the changes of temperature and precipitation, and will not directly bring a specific weather, but will have an overall impact on the short-term climate.
He said that La Nina event was seriously affected by North and South America, and its impact on China needed the help of several intermediate processes, such as ocean and atmospheric circulation, which was indirect in general. As far as China is concerned, the impact of La Nina incident on the southeast region is more obvious.
In La Nina year, the sea water at low latitudes became cold, and the original equilibrium state of the climate system was broken. Therefore, La Nina events have an important impact on regional climate anomalies in autumn and winter, such as autumn rain in West China, autumn drought in South China and autumn waterlogging in North China.
Since autumn, hundreds of weather stations have reached or exceeded the high temperature record.
The reporter learned from the National Climate Center that since the fall of this year (September 1 to1October 9 10), the national average temperature has been 16.7℃, which is 0.6℃ higher than normal, and is196/kloc-0.
Except for the lower temperatures in the west and south of Northeast China, southwest of North China, east of southwest China, east of Shandong and south of Jiangsu, most other parts of the country are close to normal or high. Among them, the temperature in southern Hunan, southwestern Jiangxi, northern Guangdong and northeastern Guangxi is 2℃ ~ 4℃ higher. The average temperature in Hunan 196 1 is the second highest in the same period in history, and the third highest in Fujian and Xinjiang. The daily high temperature of 679 national meteorological stations in China reached or exceeded the historical extreme value of the month, among which 32 1 station such as Qingyang in Anhui (40.9℃) and Yangxin in Hubei (40.6℃) reached or exceeded the historical extreme value of the season.
Since this autumn, the national average temperature anomaly distribution map. Photo courtesy of National Climate Center
Since autumn, the national average precipitation is 70.9mm, 9.9% less than normal, and the seventh least since 196 1, showing the characteristics of warm and dry climate. Central North China and Fujian, Jiangxi, south-central Hunan, southern Xinjiang, northwestern Qinghai, western Gansu and western Inner Mongolia are less than 80% to 100%. The precipitation in Fujian, Hunan and Jiangxi 196 1 year is less than that in the same period in history, and Beijing is the third least. There are also some areas where precipitation is more than normal. Among them, the precipitation in Tibet is the second largest in the same period of history, and Liaoning is the third largest in the same period of history.
Percentage distribution map of precipitation anomaly in China since this autumn. Photo courtesy of National Climate Center
With global warming superimposed on La Nina events, the frequency of warm winters in China increased.
Under the background of global warming, the impact of La Nina event on climate is more complicated. It is generally believed that when La Nina event happened, Leng Xia fever in winter and "drought in the south and waterlogging in the north" were prone to occur in China. According to the statistical data of the meteorological department on the climate characteristics of La Nina, after La Nina event, the winter temperature anomalies in China are mainly characterized by low temperature and less precipitation.
Specifically, after the La Nina incident, the temperature in most parts of the country was lower than normal, especially in northern North China, southeastern South China, most of southern China, eastern and northern Southwest China, and most of northwest China. On the other hand, there is less precipitation in winter in China, especially in the northeast, along the middle and lower reaches of the Yangtze River, in the south of southwest China and in northern Xinjiang. There is more precipitation in the north of southwest China and the east of northwest China.
It should be noted that the factors affecting the climate are not only La Nina events, but the La Nina year does not mean that the cold winter is inevitable.
Since 195 1, there have been 15 La Nina events in the equatorial Pacific. Before 1986, China was cold in winter, but under the background of global warming, after 1986, the frequency of warm winters in La Nina events increased.
In September 2022, the global sea surface temperature anomaly distribution map. Photo courtesy of National Climate Center
The winter climate conference 10 will be held in late October of 10, when new forecasts will be provided.
Typical "cold winters", such as 2008, 20 18, are all years of low-temperature freezing injury and snowstorm, in which La Nina event played a role in fueling the situation. On June 5438+ 10, 2008, Tibet suffered a wide range of heavy snowfall since meteorological data were available. On June 20 18 and10, Heilongjiang and Xinjiang suffered from low-temperature freezing snow disasters; In the year of June 5438+065438+ 10, there were four cold air processes affecting China, and Xinjiang, Qinghai and Heilongjiang suffered snowstorms.
Contrary to the above-mentioned years, La Nina events in the equatorial Pacific began to intensify in 20 1 1 year, and were assessed as normal light years of freezing damage and snowstorm by meteorological departments. In addition, the years of 200 1, 20 12, and 202 1 year, which were also affected by La Nina events, were the years of low temperature freezing injury and snow disaster.
Last winter (202 1, 12 to February 2022), the national average temperature was -3.2℃, which was 0.2℃ lower than the normal period (-3.0℃), belonging to "normal slight cold".
It should be noted that in addition to La Nina event, China's winter climate is also affected by Arctic sea ice, Eurasian snow and other factors, and the natural variability within the atmospheric circulation system also plays an important role. The National Climate Center will hold a winter climate conference in late June at 5438+ 10 to strengthen the analysis and judgment of the atmosphere-ocean coupling system and provide new forecast opinions and service information in time.