Unlike previous years, the weather this winter is unpredictable. Following the late autumn heat, the weather was mild enough to exceed 20 degrees Celsius until mid-December, but severe cold was predicted from the weekend of the 16th. The temperature dropped sharply from the daytime on the 16th, and the predicted temperature for 10 days was predicted to be between minus 16 degrees in the morning and minus 8 degrees, and between minus 6 degrees and minus 9 degrees during the day. On the 11th, a heavy rain warning was issued for the Gangwon region in December for the first time since 1999, when records were confirmed.
Experts point to El Niño, which was more active than usual, as the cause of the abnormal weather on the Korean Peninsula this winter. Analysis suggests that the connection between global warming and abnormal winter weather is also becoming more evident.
● The reason for the rampant weather is ‘El Nino’, which has become stronger.
El Niño is a phenomenon in which the surface water temperature in the East Pacific Sea Level Monitoring Area rises by 0.5 degrees above normal. As the sea water in the mid-latitude region warms, the warm air from the equatorial region expands into the mid-latitude region. Korea is located in the mid-latitude region where El Niño increases the temperature. This year is considered to be a particularly strong year for El Niño. Previously, the World Meteorological Organization (WMO) predicted that El Niño, which began in June of this year, would last until winter. In May, a prediction was made that a ‘super El Niño’ would occur, in which the eastern Pacific sea surface temperature would rise by more than 2.0 degrees. The explanation is that as El Niño lasts longer and its intensity remains at a high level, abnormal weather has become more extreme.
● It is too early to jump to conclusions that global warming is to blame.
There is also speculation that global warming may be the fundamental cause of the unusually high temperatures on the Korean Peninsula this winter and the extreme cold waves that will come in the future. The analysis is that as global warming increases ground and sea surface temperatures, phenomena such as El Niño phenomenon that have a direct impact on meteorological phenomena may occur.
According to academic circles, global warming can be assumed to be the cause of short-term abnormal weather such as heavy rain or heavy snow. As seawater warms, the amount of water evaporates in the form of water vapor increases. If sea surface temperatures remain high for a long period of time, sea water evaporates and the amount of water vapor accumulating in the atmosphere increases. This water vapor turns into snow and rain, leading to heavy rain or heavy snow.
Ice on the Arctic continent that has melted due to global warming is also a cause of abnormal weather. Kim Baek-min, a professor in the Department of Environment and Atmospheric Sciences at Pukyong National University, said, “The ‘jet stream’, which is a fast wind in the upper atmosphere, basically moves from east to west, but when the ice in the Arctic region melts, the jet stream moves north, south, east, and west. If this happens, an abnormal climate phenomenon will occur. “Blocking, which is an important factor, occurs,” he explained. Blocking refers to the phenomenon where airflow stagnates in one place for a long time. If the jet stream moves south for a long time, the cold air from the north will also come down to the mid-latitudes and be blocked, increasing the likelihood that the cold wave will last for a long time.
It is too early to tell whether global warming is the cause of abnormal winter weather. Professor Kim said, “The causal relationship between abnormal weather in the summer and global warming has been proven to some extent, but research data has only recently been accumulating on the relationship between abnormal weather in the winter.”
Research is being actively conducted to identify the causes of abnormal winter weather from various angles. In a paper published in the international academic journal ‘Nature Communications’ on the 27th of last month, researchers at the Korea Institute of Science and Technology (KIST) identified excessive heat accumulation in mid-latitude ocean fronts as the cause of frequent abnormal cold waves in East Asia and North America. The research team concluded that temporary natural variability in the Earth’s climate system led to heat accumulation in ocean fronts. Seong Mi-kyung, a senior researcher at KIST who led the study, said, “If we apply the impact of ocean fronts to a global warming climate model, we can improve the climate change outlook for the next 10 years.”
Donga Science Reporter Park Jeong-yeon [email protected]
2023-12-14 12:40:00
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