https://repository.kopri.re.kr/handle/201206/14788 2026-03-05T06:58:40Z https://repository.kopri.re.kr/handle/201206/16193 Title: Patterns of summer ichthyoplankton distribution, including invasive species, in the Bering and Chukchi Seas Authors: Kim, Sung Hoon; Son, Wuju; Yoo, Jaeill; Cho, Kyoung-Ho; Park, Taewook; Yang, Eun Jin; Kang, Sung-Ho; La, Hyoung Sul Abstract: A multidisciplinary survey was carried out in the Pacific Arctic and sub-Arctic regions of the North Pacific Ocean on the Korean icebreaking research vessel Araon. During this survey, ichthyoplankton fishes in the Pacific Arctic and sub-Arctic region ranged from the Bering Sea to the northern Chukchi Shelf in summer. The most dominant species was Gadus chalcogrammus, followed by Pleuronectes quadrituberculatus and Boreogadus saida. Gadus chalcogrammus and P. quadrituberculatus were particularly abundant near the Bering Sea and Bering Strait, whereas B. saida was dominant in the Chukchi Sea. Hierarchical cluster analysis revealed four distinct ichthyoplankton communities in Pacific Arctic and sub-Arctic regions based on geographical regions. However, Eleginus gracilis, which was previously known to be seen between latitudes 66.5 degrees N and 69.5 degrees N, was found above 70 degrees N, suggesting that its distribution extends further north. Furthermore, we noticed that Benthosema glaciale, which is usually found in the Atlantic sector of Arctic Ocean, was observed in the northern Chukchi Sea. In addition to these unusual species distributions, several species that are mainly observed in coastal areas are observed in the Chukchi Sea region. The observed influx of various uncommon fish species into the Chukchi Sea can be attributed to multiple factors, including freshwater inflow from the East Siberian Sea and the intrusion of warm Atlantic and Pacific waters, which are strongly affected by global warming. Consequently, it is imperative to conduct rigorous monitoring of the Pacific Arctic region, with a particular focus on the Chukchi Sea, to better understand the implications of global warming. 2024-04-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/15381 Title: Investigation and prediction system development of marineheatwave around the Korean Peninsula originated from thesubarctic and western Pacific Authors: Jun, Sang-Yoon 2024-02-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/15462 Title: Contribution assessment of Northern Hemispheric atmospheric circulations to Korean mid-summer surface warming by the atmospheric nudging experiment Authors: Lee, Min-Hee; 노엘; Kim, Joo-Hong; 김주완; Jun, Sang-Yoon Abstract: Anomalous surface warming in Korea has been explained by the high-pressure anomaly accompanied by the vertical sinking motion and weakening of westerlies at the exit of the East Asian Jet. The large-scale circulations linked to this high pressure over East Asia are characterized by the low pressure over the Arctic (AC) and the high pressure over Western Europe (WE), East Asia, and the North Pacifc (NP). To assess the contribution of these circulation anomalies to the hot summer in Korea, the four nudging experiments (AC, NP, AC+NP, and WE) are applied to the simulations with 50 diferent initial conditions in July. As a result, the most similar patterns on local and hemispheric scales are found in the AC+NP nudging experiment. However, the near-surface response in the AC+NP is still weak, and its center shifts to the north compared to the observed, which is induced by the weaker diabatic contribution for the downward motion in the nudging experiment. Using the quasi-geostrophic omega equation, we fnd that the simulated radiative feedback process is not sufcient to build up the large-scale subsidence with the short nudging period. Despite this limitation, AC+NP well simulates the coherent sinking motion and high-pressure system near Korea by the vorticity advection associated with the upper-level westerlies. It implies that the contribution of the North Pacifc circulation (a downstream region) should also be considered to reasonably simulate the East Asia surface warming along with those in the upstream regions. 2024-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/16192 Title: Development and Assessment of LSTM Model for Correcting Underestimation of Water Temperature in Korean Marine Heatwave Prediction System Authors: IM, NA KYOUNG; JIN, HYUNKEUN; PAK, GYUNDO; PARK, YOUNG-GYU; KIM, KYEONG OK; Choi, Yonghan; KIM, YOUNG HO Abstract: The ocean heatwave is emerging as a major issue due to global warming, posing a direct threat to marine ecosystems and humanity through decreased food resources and reduced carbon absorption capacity of the oceans. Consequently, the prediction of ocean heatwaves in the vicinity of the Korean Peninsula is becoming increasingly important for marine environmental monitoring and management. In this study, an LSTM model was developed to improve the underestimated prediction of ocean heatwaves caused by the coarse vertical grid system of the Korean Peninsula Ocean Prediction System. Based on the results of ocean heatwave predictions for the Korean Peninsula conducted in 2023, as well as those generated by the LSTM model, the performance of heatwave predictions in the East Sea, Yellow Sea, and South Sea areas surrounding the Korean Peninsula was evaluated. The LSTM model developed in this study significantly improved the prediction performance of sea surface temperatures during periods of temperature increase in all three regions. However, its effectiveness in improving prediction performance during periods of temperature decrease or before temperature rise initiation was limited. This demonstrates the potential of the LSTM model to address the underestimated prediction of ocean heatwaves caused by the coarse vertical grid system during periods of enhanced stratification. It is anticipated that the utility of data-driven artificial intelligence models will expand in the future to improve the prediction performance of dynamical models or even replace them.; 해양의 고수온 현상은 지구온난화로 인한 주요 문제 중 하나로, 식량 자원의 감소와 해양 탄소 흡수력의 저하 등, 해양 생태계와 인 류에게 직접적인 위협으로 부상하고 있다. 따라서, 한반도 주변 해역에서의 고수온 예측은 해양 환경 모니터링 및 관리에 중요하다. 본 연구에서는 역학 모델 기반 한반도 고수온 예측 시스템의 성긴 해양의 수직격자체계로 인한 고수온 예측의 과소모의를 개선하 기 위해 LSTM 모델을 개발하였다. 2023년에 대해 수행된 한반도 고수온 예측 시스템의 고수온 예측 결과와 LSTM 모델의 결과를 기반으로 한반도 주변의 동해 해역, 황해 해역 그리고 남해 해역에서의 고수온 예측 성능을 평가했다. 본 연구에서 개발된 LSTM 모 델이 세 영역 모두에서 수온이 상승하는 시기에 수온 예측 성능을 크게 개선하는 것으로 나타났으며, 수온 상승이 시작되기 전이나 하강하는 시기에는 예측 성능의 개선 효과가 미미했다. 이는 LSTM 모델이 성층이 강화되는 환경에서 성긴 수직격자로 인해 발생 하는 고수온 예측의 과소모의를 개선할 수 있는 가능성을 보여준다. 향후 역학 모델의 예측 성능 개선이나 역학 모델의 대체에 자료 기반 인공지능 모델의 활용성이 확대될 것으로 기대한다. 2024-01-01T00:00:00Z