Subseasonal, interannual, and long-term trend relationship between Arctic and Eurasian climate variability

• Main Author: 김혜진
• Other Authors: 손석우, Hye-Jin Kim, 자연과학대학 지구환경과학부
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 서울대학교 대학원 2021
• Subjects: warm Arctic-cold Eurasia; Ural blocking; transient anomaly; Arctic sea ice loss; internal variability; deep Arctic warming; 따뜻한 북극-차가운 유라시아 패턴; 우랄 블로킹; 북극 해빙 감소; 대 기 내부 변동성; 550; Arctic; Sea ice
• Online Access: https://hdl.handle.net/10371/179017; https://dcollection.snu.ac.kr/common/orgView/000000167387

학위논문(박사) -- 서울대학교대학원 : 자연과학대학 지구환경과학부, 2021.8. 손석우. The statistical relationship between Arctic and Eurasian surface air temperature (SAT) has been observed in multiple time scale, from subseasonal to multi-decadal time scales. This relationship and the underlying mechanisms are revisited using reanalysis data and climate model experiments. Since the possible mechanisms could differ by the time scale, the subseasonal and interannual-to-long term trend relationship are investigated separately. The subseasonal relationship between Arctic and Eurasian SAT is re-examined first. Consistent with previous studies, a significant negative correlation is observed in cold season from November to February, but with a local minimum in late December. This relationship is dominated not only by the warm Arctic-cold Eurasia (WACE) pattern, which becomes more frequent during the last two decades, but also by the cold Arctic-warm Eurasia (CAWE) pattern. The budget analyses reveal that both WACE and CAWE patterns are primarily driven by the temperature advection associated with sea level pressure anomaly over the Ural region, partly cancelled by the diabatic heating. It is further found that, although the anticyclonic anomaly of WACE pattern mostly represents the Ural blocking, about 20% of WACE cases are associated with nonblocking high pressure systems. This result indicates that the Ural blocking is not a necessary condition for the WACE pattern, highlighting the importance of transient weather systems in the subseasonal Arctic-Eurasian SAT co-variability. The interannual-to-long term trend relationship between the Arctic and Eurasia is also investigated. Unlike the subseasonal Arctic-Eurasian relationship, Arctic sea ice is likely attribute to the recent Eurasian winter SAT change on interannual-to-decadal time scale. The present study quantifies the statistical relationship between Arctic sea-ice loss and Eurasian winter surface air-temperature change by a break-point trend analysis and maximum covariance analysis. A ...