https://repository.kopri.re.kr/handle/201206/13429 2026-04-07T02:11:49Z 2026-04-07T02:11:49Z 김용선 권민호 Chung, Eui-Seok 예상욱 정진영 장찬주 https://repository.kopri.re.kr/handle/201206/14681 2023-10-11T16:37:20Z 2023-01-01T00:00:00Z

Title: A regime shift in the interhemispheric teleconnection between the Yellow and East China Seas and the southeastern tropical Pacific during the boreal summer Authors: 김용선; 권민호; Chung, Eui-Seok; 예상욱; 정진영; 장찬주 Abstract: A drastic regime shift is observed in the early summer connection between the Yellow and East China Seas (YECS) and the tropical Pacific in the early 2000s through statistical estimations on reconstructed datasets for the period 1982？2020. During the pre-2003 period, prior to the regime shift, the summer sea surface temperatures (SSTs) in the YECS were modulated by local oceanic and atmospheric processes, along with their marginal coupling to the tropical Pacific. In contrast, an interhemispheric coupling emerges between the YECS and southeastern tropical Pacific after the regime shift. This teleconnection is attributed to a reduced El Nino signature in the tropical Pacific, which favors the emergence of the South Pacific meridional mode (SPMM) independently from the El Nino-Southern Oscillation signals. The SPMM-related SST anomalies invoke changes in rainfall and vertical motion over the western tropical Pacific, activating the western North Pacific subtropical high over the Philippine Sea. This atmospheric circulation system acts as an atmospheric bridge to mediate the air-sea interacted variability associated with the SPMM into the YECS. The susceptibility of the YECS to atmospheric forcing highlights the role of SST in the YECS as a potential indicator of global-scale climate change.

2023-01-01T00:00:00Z 조희제 국종성 전상윤 https://repository.kopri.re.kr/handle/201206/13503 2022-06-24T16:36:34Z 2022-01-01T00:00:00Z

Title: Influence of the recent winter Arctic sea ice loss in short-term simulations of a regional atmospheric model Authors: 조희제; 국종성; 전상윤 Abstract: Notable changes in the wintertime Arctic atmospheric circulation have occurred over the last few decades. Despite its importance in understanding the recent changes in the Northern Hemisphere midlatitude climate, it remains unclear whether and how these changes are affected by recent Arctic sea ice loss. In this study, a regional scale model is used to separate the direct sea ice influence from the natural variability of large-scale atmospheric circulation. Results show that, in response to sea ice loss, the increase of geopotential height in the mid-to-upper troposphere is robust across the simulations, but the magnitude of the response is highly dependent on the background state of the atmosphere. In most cases the sea ice loss-induced atmospheric warming is trapped near the surface due to the high vertical stability of winter Arctic lower troposphere, accordingly, resulting in a small response of geopotential height. However, when a low-pressure system is located over the Barents Sea, the relatively weak stability allows an upward transport of the surface warming, causing a significantly larger geopotential height increase. This strong state-dependence of atmospheric response which is also found in recent studies using global-scale model experiments, highlights the importance of accurately representing the atmospheric background state for numerical model assessments of sea ice influence.

2022-01-01T00:00:00Z 이상빈 예상욱 이정서 박영규 권민호 Jun, Sang-Yoon 조현수 https://repository.kopri.re.kr/handle/201206/13901 2022-09-26T16:36:41Z 2022-01-01T00:00:00Z

Title: Roles of Atmosphere Thermodynamic and Ocean Dynamic Processes on the Upward Trend of Summer Marine Heatwaves Occurrence in East Asian Marginal Seas Authors: 이상빈; 예상욱; 이정서; 박영규; 권민호; Jun, Sang-Yoon; 조현수 Abstract: By analyzing the European Centre for Medium-Range Weather Forecasts reanalysis version 5 (ERA5) dataset, we found increased frequency of marine heatwaves (MHWs) in East Asian marginal seas (EAMS) during the boreal summer (June-July-August) in the recent past. To examine which processes are responsible for the upward trend of MHW occurrence, we performed three numerical simulations using Modular Ocean Model version 5 (MOM5) forced by ERA5 dataset. The first experiment used historical atmospheric variables to force the MOM5 for 1982 to 2020, which reasonably simulated the upward trend of MHWs as well as its dominant variability in terms of temporal and spatial structure in EAMS. The second (third) experiment is the same as in the first except that the atmosphere variables used to force the MOM5 consisted of thermodynamic (dynamic) variables only. The upward trend of MHW occurrence in EAMS is simulated in the first and the second experiment only. We argue that the atmosphere thermodynamic processes, in particular, the shortwave radiative forcing, play a key role in inducing the upward trend of MHW occurrence in EAMS during the boreal summer compared to the ocean dynamic processes

2022-01-01T00:00:00Z 김다슬 Jun, Sang-Yoon 이명인 국종성 https://repository.kopri.re.kr/handle/201206/14201 2023-01-02T16:37:08Z 2022-01-01T00:00:00Z

Title: Significant relationship between Arctic warming and East Asia hot summers Authors: 김다슬; Jun, Sang-Yoon; 이명인; 국종성 Abstract: Arctic warming is of growing interest because it could affect midlatitude climates.Even though numerous studies have paid attention to the relationship between Arctic warming and the midlatitude climate in winter, the influence of Arctic warming on the summer conditions has not been examined in depth. Here we identify a significant relationship between East Asia hot summers and Arctic warming over the Barents and Kara seas. To represent Arctic warming, we define a combined index by simply differencing the normalized surface air temperature and sea-ice indices. We found that the combined index in July has significantly high correlations with the temperatures in China, Korea, and Japan. While the teleconnection mechanism is not completely revealed, it is evident that warming over the Barents and Kara seas is accompanied by the local development of an anomalous anticyclone and downstream wave trains, which yield a strong anticyclonic circulation over East Asia and the North Pacific. The anticyclonic circulation persists and intensifies until August, which leads to hot summer conditions in East Asia with warm advection and enhanced shortwave radiation. Our results suggest that Arctic climate conditions can be used as a useful precursor of East Asia temperature variations even in summer

2022-01-01T00:00:00Z