Synoptic Climatic Patterns for Winter Extreme Low Temperature Events in the Republic of Korea

우리나라 겨울철 극한저온현상 발생 시 종관 기후 패턴

  • Choi, Gwangyong (Major of Geography Education, Jeju National University) ;
  • Kim, Junsu (School of Earth and Environmental Sciences, Seoul National University)
  • 최광용 (제주대학교 지리교육전공) ;
  • 김준수 (서울대학교 지구환경과학부)
  • Received : 2015.01.15
  • Accepted : 2015.02.04
  • Published : 2015.02.28

Abstract

The present study aims to characterize the synoptic climatic patterns of winter extreme low temperature events occurred in different regions of Korea based on daily temperature data observed at 61 weather stations under the supervision of the Korea Meteorological Administation and NCEP/NCAR reanalysis I data for the recent 40 years (1973~2012) period. Analyses of daily maximum and minimum temperatures below 10th percentile thresholds show that high frequencies of winter extreme low temperature events appear across the entire regions of Korea or in either the western or eastern half region divided by major mountain ridges at the 2~7 dayintervals particularly in the first half of the winter period (before mid-January). Composite analyses of surface synoptic climatic data including sea level pressure and wind vector reveal that 13 regional types of winter extreme low temperature events in Korea are closely associated with the relative location and intensity of both the Siberian high pressure and the Aleutian low pressure systems as well as major mountain ridges. Investigations of mid-troposphere (500 hPa) synoptic climatic charts demonstrate that the blocking-like upper troposphere low pressure system advecting the cold air from the Arctic toward the Korean Peninsula may provide favorable synoptic conditions for the outbreaks of winter extreme low temperature events in Korea. These results indicate that the monitoring of synoptic scale climatic systems in East Asia including the Siberian high pressure system, the Aleutian low pressure system and upper level blocking system is critical to the improvement of the predictability of winter extreme low temperature events in Korea.

Acknowledgement

Supported by : 기상청