Expert interpretation of the Arctic Oscillation
In the winter of 2009, parts of the northern hemisphere, including northern Asia, the eastern United States, and Europe, experienced rare severe cold. The reason was caused by the abnormal phenomenon of cold air being released from the Arctic about once every 30 years.
The Japan Meteorological Agency stated that it has confirmed that there is an "Arctic Oscillation" phenomenon in which cold gas in the Arctic Circle accumulates and releases repeatedly. This phenomenon has had a huge impact on the climate of the northern hemisphere. The cold air index released by the Arctic this winter, calculated using reliable data, is the highest since 1979. The result is lower than normal temperatures in mid-latitudes and warmer than normal temperatures in areas around the Arctic.
In the winter of 2009, the surface temperature of the sea surface in Peru, South America, increased abnormally, resulting in the "El Niño" phenomenon. The temperature near the equator was higher than in normal years. Although Japan is also affected by the "Arctic Oscillation", the "El Niño" phenomenon that occurred this winter is relatively strong. Therefore, despite the large temperature difference, the average temperature is high.
"Oscillation" leads to "cold winter"
Yuan Zipeng said that the biggest impact of the Arctic Oscillation is to bring cold air from the north. Generally, the Arctic is the source of cold air in the Northern Hemisphere, and it is the coldest here. But there was an unusual change in 2009. Siberia outside the Arctic Circle was the coldest. The cold in northern China is mainly related to the cold current in Siberia, which makes the cold air drive straight into Liaoning, leading to the emergence of "cold winter".
According to statistics from the meteorological department, winter entered Liaoning on October 19, 2009, one day earlier than normal. Although the onset of winter was only one day earlier, the subsequent coldness was impressive: cold wave weather occurred frequently, and the number of large-scale snowfalls reached 16 times, making it the second-highest number of large-scale snowfalls in the history of complete meteorological records. Second in 1965.
The Arctic Oscillation is a climate anomaly that has a corresponding quasi-period based on annual changes. However, due to changes in atmospheric circulation, its movement patterns are uncertain. The data shows that "oscillations" have a 40-60 day cycle within the season, as well as 2-year and 11-year cycles.
In Liaoning, the climate is also affected by the Arctic Oscillation. Just because it affects different locations, the resulting situations are also different. For example, the Arctic Oscillation occurred in 2008. Its direct impact was drought and lack of rain in the north, while rain, snow and ice appeared in the south. This situation occurs because the cold air drives southward and affects the Yangtze River Basin. The impact is different depending on the location.
Global warming is difficult to suppress
Can the severe cold weather in the winter of 2009 stop the trend of global warming? Yuan Zipeng told reporters that the general trend of global warming will not change.
He said that under the background of global warming, the Arctic Oscillation anomaly occurs in a certain year, causing the cold air to be more active. This phenomenon is very abnormal and is a manifestation of extreme weather and climate. In 2009, the frequent rain and snow in the north and the drought in the five southern provinces corresponded to each other. These are also extreme weather and climates. The frequent occurrence of these extreme weather events proves that the trend of global warming is irreversible.
Global warming not only increases the global average temperature, but also increases the probability of extreme weather such as high temperatures, droughts, cold waves, blizzards, and heavy rains. In January 2010, cold snaps and blizzards hit the northern hemisphere, paralyzing traffic in many countries in Asia, Europe, and North America, disrupting people's normal lives, and killing more than a hundred people.
South Korea: Most areas experienced heavy snowfall on January 4. As of 2 p.m., the snow accumulation in the capital Seoul exceeded 28 centimeters, which was the thickest snow accumulation since records began in 1937. Snowfall. United States: A snowstorm brought 83 centimeters of snow to the northeastern state of Vermont, breaking the previous record of 76 centimeters set in 1969. The snow thickness in some areas of New York State has exceeded 1 meter. Nearly 10 people died due to the cold weather.
UK: The UK is experiencing its longest cold wave since 1981. The snowfall has forced the closure of many airports in the UK, including Gatwick, the second largest, while many flights have been delayed at some airports such as London Luton. Since January 23, affected by frequent cold air attacks, -40℃ low temperature weather has occurred in Mohe, Heilongjiang, Hulunbuir, Inner Mongolia and other places in China. Low temperature weather has lasted for more than ten days in some areas. January 30-31, Hulunbuir City Hailar Station (-42.9℃), Manzhouli Station (-42.2℃), Chenbarhu Banner Station (-45.5℃), New Barhu Right Banner Station (-38.6℃), Xilingol League The daily minimum temperature at Sunit Left Banner Station (-35.8℃) reached or exceeded the extreme low temperature threshold, and extreme low temperature weather events occurred.
Italy: Parts of the country are covered in ice and snow. Traffic in northern and central Italy was disrupted due to snowfall, and more than 600 passengers had to be stranded on trains overnight. The severe cold killed an infant, a 76-year-old man and a homeless man. The local meteorological station stated that this was the coldest winter in Italy in 27 years.
France: Severe cold warnings have been issued for nearly half of the region. The army established 600 shelter centers in Paris to house homeless people.
Germany: Snowfall continues in Berlin, with temperatures dropping to -10°C.
Belgium: The Manneken Pis sculpture, a famous tourist attraction in Brussels, "struck down" due to freezing due to low temperatures.
Poland: The temperature plummeted to -32°C. Police said that nine more people froze to death on the 2nd, bringing the number of people who have froze to death in Poland since the temperature dropped last week to 29.
Ukraine: It is a country that has been greatly affected by this cold wave. According to statistics released by the Ministry of Health of Ukraine on the 2nd, 101 people froze to death in the country in the past week, 64 of whom froze to death on the streets, and some died after being sent to the hospital. The temperature in the capital Kiev dropped to -27°C on the 2nd, and the temperature in the Carpathian Mountains region fell below -30°C. Tens of thousands of people took refuge in more than 2,000 temporary shelter centers to avoid the cold. (Wang Xiyi)
Japan: Heavy snowfall occurred in various areas across the country, and the snow accumulation in some areas even exceeded 5 meters. As of the 2nd, weeks of heavy snowfall in northern Japan have triggered avalanches and disrupted transportation networks, killing at least 56 people. Japan's Hokkaido and northern Honshu islands have been covered in thick snow. The temperature in Aomori, Japan dropped to -9.2°C on the 2nd, and the snow depth reached 4.29 meters.
Romania, Serbia, Bulgaria and other European countries: A total of at least 30 people died due to cold weather, including 22 in Romania. In Sofia, the capital of Bulgaria, local media reported that money in cash machines was frozen, causing the machines to malfunction. The severe cold also caused parts of the Danube River to freeze. To protect the ships, Bulgarian authorities had to move some ships to other ports. At least 10,000 people in Serbia are stranded in remote villages due to traffic disruptions. Some Bosnian villages also rely on military helicopters to airdrop food and other necessities. In Latvia, 10 people froze to death in the capital Riga alone, and the number of deaths in other areas has yet to be counted. In Estonia, organizers had to stop hosting ski competitions as temperatures dropped below -30°C.
The 2016 Cold Wave
El Niño should have caused the warm winter, but because El Niño triggered the Arctic Oscillation, a large amount of cold air from the Arctic moved south, causing a cold winter.