https://repository.kopri.re.kr/handle/201206/9423 2026-03-29T14:33:42Z https://repository.kopri.re.kr/handle/201206/16461 Title: Synchronous mid-Holocene marine and terrestrial deglaciation in the Ross Sea, Antarctica Authors: Parker Rebecca L.; Riesselman Christina R.; Truax Olivia J.; Jones Richard S.; Lee, Jae Il; Lee, Min Kyung; Jacobsen Geraldine; Rosenheim Brad E.; Subt Cristina; Zawadzki Atun; Ginnane Catherine; Naeher Sebastian; Dunbar Gavin; McKay Robert M.; Levy Richard; Turnbull Jocelyn; Yoo, Kyu-Cheul Abstract: The Ross Ice Shelf buttresses ice draining from both East and West Antarctica and its collapse could accelerate the loss of inland ice sheets, rapidly raising sea level. Documenting the location, timing and rate of past glacial retreat can help reveal processes driving rapid mass loss, informing projections of ice sheet responses to a warming climate. Here, we present a record of mid-Holocene ice retreat from the southwestern Ross Sea using facies succession and paired ramped pyrolysis oxidation C-14/Pb-210 chronology. This record shows rapid ice shelf retreat from 6.9-5.4 cal kyr BP, coeval with thinning of adjacent outlet glaciers. Our findings reconcile earlier discrepancies in terrestrial and marine reconstructions, and indicate that synchronous grounding line retreat from west of Ross Island to the Siple Coast at similar to 7-6.2 cal kyr BP was likely driven by warm-water incursions, a process active in parts of Antarctica today. 2025-12-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/16601 Title: Increased Sea Ice Duration in Moubray Bay, Northwest Ross Sea Linked to Early Holocene Wind Strength Authors: Gilmer Greer; Riesselman Christina R.; Kim, Sunghan; Yoo, Kyu-Cheul; Lee, Jae Il; Lee, Min Kyung; Ginnane Catherine E.; Rosenheim Brad E.; Turnbull Jocelyn; Parker Rebecca; Jacobsen Geraldine; Mckay Robert; Levy Richard; Moy Christopher M. Abstract: Sea ice in the Ross Sea plays a critical role in the formation of dense water masses, ice sheet stability, and air-sea gas exchange, and also supports unique ecosystems. However, its seasonal and spatial variability makes it challenging to include in model simulations. To address this, new sea ice records that extend beyond the satellite era and include periods of climate change are essential. This new sediment record from Moubray Bay, northwest Ross Sea, reconstructs environmental conditions between similar to 11,300 and similar to 10,900 cal yr BP-a time of rapid retreat of marine-based ice sheets and coastal glaciers in the region. The diatom assemblage is dominated by three taxa: Fragilariopsis curta, Corethron pennatum, and Chaetoceros resting spores. Variations in their relative abundances reveal changes in wind strength, water column structure, and sea ice concentration and duration. Between similar to 11,300 and similar to 11,200 cal yr BP, environmental conditions are characterized by a stabilized water column due to fresh meltwater influx, and weaker winds, which resulted in shorter sea ice duration and reduced winter sea ice concentration. This continued after similar to 11,200 cal yr BP but stronger winds linked to deepening of Amundsen Sea Low-like circulation triggered short-term water column stratification. Sea ice concentration and duration increased after similar to 11,100 cal yr BP driven by cooling of the sea surface by stronger southerly winds. Concurrent changes in early Holocene marine and terrestrial climate records from the Ross Sea indicate a shift in atmospheric circulation during the early Holocene. 2025-12-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/16561 Title: Disappearance of the El Nino-driven surface mass gain in West Antarctica under future climate change Authors: Lee, Hyun-Ju; Jin, Emilia Kyung; Kim, Byeong-Hoon; Lee, Won Sang Abstract: Strong El Nino events drive substantial snowfall in West Antarctica, including the Antarctic Peninsula, by weakening the Amundsen Sea Low (ASL) through atmospheric teleconnections, increasing surface mass balance and mitigating ice mass loss’s contribution to sea-level rise. However, we find that CMIP6 projections show a diminishing El Nino-driven precipitation effect as global warming intensifies. The El Nino-associated precipitation anomaly is projected to weaken in SSP3-7.0 and SSP5-8.5, becoming indistinguishable from zero by the late 21st century in the latter. This transition is caused by a strengthened polar jet, linked to a positive Southern Annular Mode (SAM) trend in a warmer climate, which extends the wavelength of Rossby waves. As a result, the ASL anomaly eventually migrates eastward and equatorward, reducing water vapor transport into West Antarctica’s interior. These findings indicate that El Nino-driven precipitation disappears in a high-emission future, eliminating one of the buffering mechanisms that help counteract sea-level rise. 2025-11-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/16572 Title: Bromide oxidation by bromate in a frozen solution and reactive bromine species production Authors: Ahn, Yong-Yoon; Quoc Anh Nguyen; Andrea Spolaor; Sefano Frassati; Elena Barbaro; Giulio Cozzi; Clara Turetta; Hoon Oh; Jaesang Lee; Kim, Kitae Abstract: A sudden increase in tropospheric reactive bromine species (such as BrO radical) concentration has been observed in the Arctic springtime (bromine explosion). The reactive bromine radicals originate from the Br2 oxidation; however, the role of ice chemistry in bromine activation, especially freezing-induced Br- oxidation for Br2 production, is not significantly considered yet. Notably, the freezing phenomenon is prevalent in polar region. In this study, we demonstrate that the Br- containing water freezing can provide a potential Br- oxidation pathway. The oxidation of Br- by BrO3- was negligible under aqueous conditions, while it was highly accelerated (time scale of several years to minute) by freezing the solution. We proposed that the accelerated chemical reaction was due to the freezing concentration effect. The chemical transformation mechanism was suggested. The chemical transformation of Br- was considered using the UV-visible absorbance spectrometer and the high-resolution mass spectroscopy (HRMS) measurement. The total Br content was measured using inductive coupled plasma mass spectroscopy (ICP-MS) and the dissolved Br species was monitored using ion chromatography. The spatial distribution of in-situ generated hypobromous acid in ice was analyzed using the Raman microscopy. The Br- oxidation is increased as the decrease of initial pH and increase of reactant dose, but the influence of freezing temperature was not significant. This study provides experimental evidence for the freezing-induced bromide activation in the ice. 2025-10-01T00:00:00Z