Why this fall is unusually warm

The Korea Times

The Korea Times

National

Wed, November 29, 2023 | 20:14

Society

Why this fall is unusually warm

Posted : 2022-11-23 16:43

Updated : 2022-11-24 17:13

People wearing short sleeves are seen walking in Namsan Park in Seoul, Nov. 20. Yonhap

By Lee Hyo-jin

With the unseasonably warm weather continuing in recent weeks, it's hard to believe that winter is just around the corner. Cold weather typically starts here in mid-November, but the country is seeing the warmest November in a decade.

Tuesday was "Soseol," which in Korean means "small snow," and is one of the 24 seasonal divisions of the traditional Korean lunar calendar. According to the calendar, the season's first snow falls around this time of the year. But due to the higher-than-usual temperatures, the country saw rain instead. Additionally, the unseasonal blooming of spring flowers has been witnessed in southern regions.

According to data from the Korea Meteorological Administration (KMA), the average maximum daily temperatures in Seoul from Nov. 1 to 20 this year stood at 16.7 degrees Celsius, the highest figure in a decade. The maximum daily temperature on Nov. 20 was 20.2 degrees Celsius, about 10 degrees Celsius higher than the average on the same days over the past decade.

Many people are still suffering from mosquito bites, which are thriving in the mild weather. The bloodsucking insects go dormant when the daytime temperature falls below 13 degrees Celsius.

Seoul City's digital mosquito monitoring system (DMS), which is installed throughout districts to measure the number of mosquitoes, tracked 1,157 mosquitoes in the second week of November, more than double the 457 it had measured during the same period in 2021.

Moreover, the unusually warm month is forcing ski resorts in the mountainous regions of Gangwon Province to push back their opening day. Yongpyong Resort and Phoenix Pyeongchang, both of which were originally scheduled to open at the end of November, have recently announced that they will postpone their openings until December.

Experts attributed the record-setting warm autumn weather to two main factors: the extended positive phase of the Arctic Oscillation ― the oscillation of atmospheric pressure between the Arctic and middle latitudes of the North Pacific and North Atlantic ― which is keeping the cold air trapped in the arctic polar region and allowing warmer air from mainland China to blow eastward toward Korea.

People walk on the streets in central Seoul, Monday. Korea Times photo by Seo Jae-hun

The Arctic Oscillation has a significant influence on the weather and climate of the continents including Asia, especially during winter. Typically, Korea's cold winter weather is induced by a negative phase of the Arctic Oscillation which steers cold air southward.

"Basically, the cold front trapped in the north, plus the warm air blowing from mainland China ― both of which are quite unusual at this time of the year ― are resulting in the unseasonal warm weather," Woo Jin-kyu, an official at the KMA, told The Korea Times.

"The current trend is expected to persist toward the end of this month. We are predicting nationwide rainfall on Nov. 28 and 29, which is expected to drastically change the air pressure. And temperatures may drop sharply after the rain," he said, warning of a possible cold wave alert in early December.

Woo also said that the current warm spell does not necessarily mean that this winter will be mild too.

However, he was cautious to link the abnormal weather with global warming. "Scientifically speaking, it's hard to say that this particular phenomenon is a result of global warming and rising temperatures," he said.

On the other hand, Kim Hae-dong, a professor of the global environment at Keimyung University, said the unseasonal warmth could be one of the signs highlighting the seriousness of global warming.

"Of course, it is hard to link every single extreme weather event with global warming, but we should look at the worsening frequency and impact of these unusual climate events. The rising global average temperature is associated with widespread changes in weather patterns, which we have been seeing quite frequently in recent years," he said.

According to Kim, the country saw unseasonal warm weather in the winter of 2016, when temperatures rose to as high as 16 degrees Celsius in some regions.

He said, "The fact that we are seeing unseasonal weather conditions yet again in less than six years is quite concerning."

lhj@koreatimes.co.kr