DSpace Collection: https://repository.kopri.re.kr/handle/201206/11574 2026-04-17T14:22:23Z Application of the PIP25 index for reconstructing spring sea ice concentration in the western Arctic Ocean https://repository.kopri.re.kr/handle/201206/12359 Title: Application of the PIP25 index for reconstructing spring sea ice concentration in the western Arctic Ocean Authors: Kim, Jung-Hyun; Kim, Dahae; Jun, Sang-Yoon; Joe, Young Jin; Ahn, Youngkyu; Park, Kwangkyu; Nam, Seung-il Abstract: Arctic sea ice plays an important role in the global climate system via the sea ice-albedo feedback. Reliable satellite-derived records of the Arctic sea-ice extent have only been available since 1979. Hence, reconstructions of sea ice conditions on time scales beyond satellite measurements are necessary to understand natural, longer-term sea ice changes and their driving mechanisms under various climate forcings. In this study, we investigated 53 surface sediments collected from the Chukchi Sea and the East Siberian Sea during the Arctic cruises with RV Araon from 2010 to 2019. We aimed to assess the applicability of the PIP25 index, based primarily on the use of HBI III as a semiquantitative sea ice proxy in the western Arctic Ocean. Our preliminary results showed the presence of IP25 in all sediment samples investigated, confirming the occurrence of seasonal sea ice in the study area. Nonetheless, further works are necessary to establish a regional balance factor c value, a term used to calculate the PIP25 index in the western Arctic Ocean. 2020-01-01T00:00:00Z Source of sedimentary organic carbon along a Mackenzie Trough transect in the Canadian Beaufort Sea https://repository.kopri.re.kr/handle/201206/12360 Title: Source of sedimentary organic carbon along a Mackenzie Trough transect in the Canadian Beaufort Sea Authors: Kim, Dahae; Kim, Jung-Hyun; Kang, Sujin; Park, Kwangkyu; Lee, Dong-Hun; Jin, Young Keun; Nam, Seung-il; Shin, Kyung-Hoon Abstract: The Arctic is warming twice as fast as other parts of the Earth. Thus, the release of vast amounts of organic carbon (OC) from the terrestrial permafrost to the Arctic Ocean is expected to be accelerated through several pathways including river discharges. The Mackenzie River, which is the fourth-largest Arctic river in terms of freshwater discharge, but the first in terms of sediment discharge, is thus the most important source of terrestrial freshwater and sediment input to the Beaufort Sea. In this study, we investigated surface sediments collected along a Mackenzie Trough transect during the ARA04C, ARA05C, and ARA08C expeditions of the Korean ice-breaker R/V Araon in the Canadian Beaufort Sea in 2013, 2014, and 2017, respectively. We analyzed the samples for bulk (grain size, major element, TOC, TON, δ13Corg, and △14Corg) and molecular (n -alkanes and sterols) parameters to assess the source of sedimentary OC. Our results provide information on the effect of the recent Arctic warming on the land-ocean terrestrial OC transfer in the Canadian Beaufort Sea. 2020-01-01T00:00:00Z Tracing terrestrial organic matter along the Mackenzie Trough in the Beaufort Sea https://repository.kopri.re.kr/handle/201206/12346 Title: Tracing terrestrial organic matter along the Mackenzie Trough in the Beaufort Sea Authors: Kim, Dahae; Kim, Jung-Hyun; Tesi, Tommaso; Kang, Sujin; Nogarotto, Alessio; Park, Kwangkyu; Lee, Dongheon; Jin, Young Keun; Nam, Seung-il; Shin, Kyung-Hoon Abstract: Recent Arctic warming accelerates the release of vast amounts of organic carbon from the terrestrial permafrost to the Arctic Ocean, having the potential to affect Arctic biogeochemical carbon cycles. The Mackenzie River is one of the largest rivers draining into the Arctic Ocean and the most important source of terrestrial freshwater and sediment input to the Beaufort Sea. In this study, we investigated surface sediments collected along the Mackenzie Trough during the ARA04C, ARA05C, and ARA08C expeditions of the Korean ice-breaker R/V ARAON in the Canadian Beaufort Sea in 2013, 2014, and 2017, respectively. We analyzed the samples for bulk (TOC, TON, C/N ratio, δ13CTOC, and δ15NTON)and molecular(concentrations and δ13C of n-alkanes, lignin phenols) parameters to trace the terrestrial organic matter input from the Mackenzie River to the Beaufort Sea. In addition, we analyzed the radiocarbon content (Δ14C) to calculate the petrogenic contribution of OC to the total OC pool. Our results provide information on the effect of thawing permafrost and thus the contribution of the activated old OC along the Mackenzie Trough. 2020-01-01T00:00:00Z