https://repository.kopri.re.kr/handle/201206/1 2026-07-16T10:14:42Z https://repository.kopri.re.kr/handle/201206/16825 Title: The chromosome numbers, ploidy levels, and Genome sizes of Svalbard plants Authors: Lee, Yoo Kyung Abstract: Background: Accurate estimation of genome size and determination of ploidy levels are fundamental for understanding plant genome architecture and their adaptive strategies in extreme environments. The Arctic region of Svalbard hosts a distinct vascular plant flora adapted to harsh climatic conditions, but comprehensive cytogenetic data remain scarce. This study compiles and analyzes chromosome numbers, ploidy levels, and genome sizes (C-values) for 188 plant taxa of Svalbard, providing essential baseline data for evolutionary and ecological research. Results: Chromosome counts in Svalbard flora range from 2n = 10 to 270, with modal base numbers of x = 7 and x = 8. Polyploidy is widespread, with diploids representing 94 taxa followed by tetraploids, hexaploids, and higher even ploids. Genome sizes (1C-values) exhibit considerable variation both within and between families. Notably, chromosome number and genome size are decoupled in Cyperaceae and Poaceae, attributed to the difference of chromosome size. The prevalence of polyploid taxa is linked to increased genetic diversity and potential epigenetic mechanisms promoting survival in the Arctic’s cold, nutrient-poor, and short growing season environments. Conclusions: This comprehensive cytogenetic dataset provides a critical foundation for ongoing and future studies on plant adaptation, evolution, and genome dynamics in Arctic ecosystems. The findings underscore the ecological importance of polyploidy and genome structural variation in shaping the resilience of polar flora under climatic stress and global change. These data will enhance molecular, ecological, and conservation research efforts in Svalbard and other high-latitude regions. 2026-02-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/16826 Title: A seismic analysis of sub glacial lake D2(Subglacial Lake Cheongsuk) beneath David Glacier, Antarctica Authors: Ju, Hyeon Tae; Kang, Seung-Goo; Choi, Yeonjin; Pyun Sukjoon; Lee, Min Je; Kwak, Hoje; Kim, KwanSoo; Kim, Yeadong; Lee, Jong Ik Abstract: Subglacial lakes beneath Antarctic glaciers are pivotal in advancing our understanding of cryosphere dynamics, basal hydrology, and microbial ecosystems. We investigate the internal structure and physical properties of Subglacial Lake D2 (SLD2), which is located beneath David Glacier in East Antarctica, using seismic data acquired during the 2021/22 austral summer. The dataset underwent a comprehensive processing workflow, including noise attenuation, velocity analysis, and prestack time migration. The migrated seismic sections revealed distinct reverse-polarity reflections at the glacier-lake interface; however, reflections from the lake-bed sediment interface were ambiguous, leading to interpretational uncertainty about the presence of a sediment layer. To resolve this interpretational uncertainty, two alternative structural models were established: Model 1 (no sediment) and Model 2 (with a sediment layer). Synthetic seismograms generated by wave-propagation modeling were compared with field data to validate the subglacial lake structure. The results confirmed the water column thickness to be approximately 82 m (Model 1) or approximately 10 m (Model 2), and possible structural scenarios for the subglacial lake were presented. Additionally, discontinuous reflections detected in seismic sections transverse to the ice flow were interpreted as scour-like feature surfaces formed by ice movement. This study identified the basal structure beneath the subglacial lake, which had been challenging to identify with conventional radar surveys, through seismic surveying. In addition, ambiguous signals in the field seismic data were mitigated via quantitative comparison with synthetic data, thereby facilitating interpretation of the underlying structure. Collectively, these findings enhance our understanding of subglacial lake environments and inform the selection of future drilling sites for in situ sampling. 2026-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/16471 Title: Grain-size and geochemical evidence for sediment transport mechanisms in the northeastern part of the East Siberian Sea and on the adjacent continental slope Authors: Ovsepyan Ekaterina; Dorokhova Evgeniia; Ovsepyan Yaroslav; Aliev Ramiz; Jin, Young Keun Abstract: Grain-size analyses, end-member modeling, X-ray fluorescence, and radionuclide activity measurements were conducted on sediment minicores collected from the middle-outer shelf of the East Siberian Sea (ESS) and the upper part of the adjacent continental slope to elucidate the sedimentation mechanisms in this poorly studied region. The grain-size data demonstrate that clayey silt and silt strongly dominate on the ESS shelf and the continental slope. In contrast, sandy silt has a patchy distribution. End-member modeling, applied here for the first time, indicates that sea ice (frazil and anchor ice) rafting, and nepheloid transport are the primary processes responsible for distributing sedimentary material across the ESS. The XRF data confirm the results of previous studies, reporting a predominantly lithogenic origin for ESS deposits. Combined grain size and geochemical records suggests that the shelf break area serves as a depocenter for fine silt particles, likely supplied by nepheloid flow, and represents the most productive area in the northeastern ESS. High sea surface productivity likely results from influence of nutrient-rich Pacific-derived waters, the upwelling of transformed Atlanticderived waters, or a combination of both. The accumulation of the high amount of fine silt near the shelf break is suggested to be related to relatively calm bottom-water conditions, resulting from the potential interaction of the northward-flowing cross-shelf currents and episodic southward-moving compensatory flows. Wind direction is considered a key factor controlling the intensity of fine-grained material distribution by nepheloid flows and anchor ice across the ESS shelf. Sedimentation rates derived from the radionuclide activity measurements vary from 1.3 mm yr(-1) on the outer shelf to 1.0 mm yr(-1) on the upper continental slope. 2025-12-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/16469 Title: Wind-Induced Topographic Rossby Waves in the Southwestern Slope of the Chukchi Abyssal Plain Authors: Ku Ahyoung; Donohue Kathleen A.; Watts D. Randolph; Kim Kiduk; Song Hajin; Jeon Chanhyung; Park, Taewook; Cho, Kyoung-Ho; Peacock Thomas; Park Jae-Hun Abstract: Near-bottom currents collected over 1 year (August 2021-22) using a current- and pressure-recording inverted echo sounder (CPIES) at a depth of 1060 m showed fluctuations within a frequency band between 2 and 6.5 days near the southwestern slope of the Chukchi Abyssal Plain. The amplitude of the fluctuations was approximately 8 cm s21 on average during the summer months and weakened to approximately 3 cm s21 between February and June 2022. Similar fluctuations were reproduced by the data-assimilated Hybrid Coordinate Ocean Model (HYCOM), confirming that they were bottom intensified. Calculations of the bottom-trapping scale using HYCOM revealed that these fluctuations could be attributed to topographic Rossby waves (TRWs) with a length scale of approximately 50 km. The spatial distributions of TRWs in HYCOM and ray-tracing results suggest that TRWs likely propagated from the west-southwest. It is suggested that these TRWs were triggered by nonlocal wind stress curl (WSC), 220 km to the west along the continental slope, as the coherence in the TRW frequency band between the TRWs and WSC was significant. The weaker TRW signal from February to June 2022 was related to weaker WSC and higher sea ice concentration in the study area. The stronger TRWs from July to October occurred when the WSC was stronger and the sea ice concentration was lower in the study area. Our findings imply that changes in the Arctic WSC field or a longer sea ice-free season could trigger more energetic and frequent TRWs, observable down to 1000-m depth around the southwestern slope of the Chukchi Abyssal Plain. 2025-12-01T00:00:00Z