The present study aims to analyze climate change and trend of extreme temperature events occurred over the Republic of Korea. The observation data used are daily average, maximum, and minimum temperature from 6 weather stations for the period of 1912-2020. Seven extreme indices regarding frequency and extreme value of temperature are calculated in seasonal and annual time range. In addition, hot extremes and their changes by four physical terms that include information on the annual mean temperature, the amplitude of the annual cycle, the diurnal temperature range and the local temperature anomaly on the day of the extreme are analyzed. The climatology for the analysis is updated to the new normal year of 1991-2020. Consistent with the previous findings, statistically significant change was detected in the indices of annual lowest daily minimum temperature, annual extreme temperature range, frequency of daily minimum temperature below -12℃ and 10%ile(TN10p) during winter. Due to the gradual decrease of the occurrence days regarding the extreme minimum temperature during winter, the frequency calculated by the relative threshold in extreme high temperature during summer prevail since 1990s. Indices related with extreme high temperature had larger low-frequency variability than significant climate change during the analysis period. However, the assessment of hot extremes according to the terms describing mean, variability and tails during the new normal year of 1991-2020, significant increasing trend was detected not only in the annual mean and the amplitude of the seasonal cycle, but also in the daily hot extreme anomaly.

Abstract
1. 서론
2. 연구자료 및 방법
3. 극한기온 발생빈도의 변화 경향
    1) 절대적 기준에 의한 발생빈도
    2) 상대적 기준에 의한 발생빈도
4. 극한기온 발생 극값의 변화 경향
    1) 장기간 변화 경향(1912~2020년)
    2) 신 평년 기간 변화 경향(1991~2020년)
5. 결론 및 토의
Reference

• 문자연((주)포디솔루션 기업부설연구소) | Ja-Yeon Moon (Research Institute, 4D Solution, Co., Ltd.) Correspondence
• 김기영((주)포디솔루션) | Ki-Young Kim (4D Solution, Co., Ltd.)