제주도 지역 체감온도 극한현상 발생 시 종관 기후 패턴

Abstract

The purpose of this study is to characterize the synoptic climatic patterns of extreme humansensible temperature (HST) events in Jeju Island, Korea under a subtropical climate condition as well as to examine their teleconnections with the large-scale climate systems. According to the extreme case analysis of the recent 30 years (1988-2017) data sets, the maximum daily average HST in the coastal areas of Jeju Island can rise up to about 40°C in mid-summer and even up to about 48°C during mid-daytime. These extreme HST events occur when the expansion of subtropical Pacific high pressure toward East Asia as well as the poleward shift of the Changma front provides hot and humid conditions over Jeju Island surrounded by seas, particularly in La Niña years with a positive (+) Arctic Oscillation mode. In contrast, the intensified western high and eastern low dipole pressure pattern in mid-winter, which accompanies the downward shear of upper tropospheric cold air toward the southern region of the Korean Peninsula under a negative (-) Arctic Oscillation mode, provides favorable conditions for frequent low HST extreme events. These conditions can lower daily average HST as much as -10°C in the coastal region of Jeju Island, and lower nighttime HST by -25°C on the peak areas of Mt. Halla due to wind chill effects. These findings will be used as a base for establishing prediction and warming systems of extreme HST events on Jeju Island, which is needed to mitigate the damage to the lives of Jeju residents and tourists under climate change.