@article {2957,
	title = {Large fluxes of continental-shelf-borne dissolved organic carbon in the East China Sea and the Yellow Sea},
	journal = {Marine Chemistry},
	volume = {240},
	year = {2022},
	month = {Jan-03-2022},
	pages = {104097},
	abstract = {Fluxes of dissolved organic carbon (DOC) from continental shelves to the ocean may play a critical role in marine carbon cycling and budget. However, these fluxes have been poorly constrained because complicated biogeochemical reactions of riverine, atmospheric, and marine organic carbon occur in continental shelf-waters. We used multiple tracers of DOC such as stable- and radiocarbon isotope ratios of DOC, fluorescent properties of dissolved organic matter (FDOM), and 228Ra as a water age tracer to investigate the sources and fluxes of DOC in the northwest Pacific continental margin of the East China Sea and the Yellow Sea. Here, we show that there are significant additional (excess) supplies of DOC in the central Yellow Sea relative to the Changjiang (Yangtze River) source, based on these tracers. The marine δ13C signature (-21.1 {\textpm} 1.1{\textperthousand}) and the radiocarbon age (2000 {\textpm} 400 yr) of DOC suggest that the additional DOC (Δ14DOC = -44{\textperthousand}) is supplied from a combination of newly produced DOC and the degradation of particulate as well as sedimentary organic matter. The flux of this additional DOC produced in the continental shelf of the East China Sea to the open ocean is estimated to be ~1.9 {\textpm} 0.8 Tg C yr-1, which is comparable to that from the Changjiang discharge. Our study implies that the fluxes of continental shelf-borne DOC may be important globally and should be considered in estimating global DOC budgets in the marine environment.},
	issn = {03044203},
	doi = {10.1016/j.marchem.2022.104097},
	url = {https://linkinghub.elsevier.com/retrieve/pii/S0304420322000147},
	author = {Han, Heejun and Na, Taehee and Cho, Hyung-Mi and Kim, Guebuem and Hwang, Jeomshik}
}
@article {2953,
	title = {Sources and Behavior of Particulate Organic Carbon in the Yellow Sea and the East China Sea Based on 13C, 14C, and 234Th},
	journal = {Frontiers in Marine Science},
	volume = {9},
	year = {2022},
	month = {Jan-04-2022},
	abstract = {The cycling of particulate organic carbon (POC) in continental shelf regions of the Yellow Sea (YS) and the East China Sea (ECS) was investigated by analyzing the concentrations and carbon isotope signatures (δ13C, Δ14C) of POC, together with the particulate aluminum (Al) concentration and 234Th activity over the period 10{\textendash}20 August 2020. POC concentrations in the surface layer (0{\textendash}20 m) were twice as high as those in the middle layer (20{\textendash}50 m); the highest concentrations of all were observed in the bottom layer (> 50 m) of the YS and the region affected by Changjiang Diluted Water (CDW). Particulate Al concentrations in the bottom layer were three times higher than those in the overlying water column, indicating extensive sediment resuspension. Based on the three-endmember mixing model for the dual carbon isotopes, the estimated contribution of resuspended sedimentary organic carbon to POC ranged from 18\% in the surface layer to 65\% in the bottom layer. The contribution of riverine input to POC ranged from < 5\% in the CDW region to \~{}45\% in the surface layer of the YS region, whereas that of in situ production was \~{}40\% in the entire study region. A deficiency of 234Th relative to 238U indicates short residence times of particles in the entire water column (2.6 {\textpm} 2.2 d). The flux of POC settling to the seafloor, calculated based on 234Th{\textendash}238U disequilibrium, was 47{\textendash}125 mmol m{\textendash}2 d{\textendash}1. The POC settling flux was one to two orders of magnitude higher than the burial rate of POC in the underlying sediment, implying the rapid decomposition of POC before incorporation into the sediment. Thus, sediment resuspension is prevalent and an important component of the POC cycling in this shelf region. Overall, our study revealed the complex nature of POC cycling on this shelf, quantified the relative importance of each source of POC, and determined POC flux to the sediment.},
	doi = {10.3389/fmars.2022.793556},
	url = {https://www.frontiersin.org/articles/10.3389/fmars.2022.793556/full},
	author = {Seo, Junhyeong and Kim, Guebuem and Hwang, Jeomshik}
}
@article {2935,
	title = {Characteristics of sediment resuspension on a deep abyssal plain in the Eastern Tropical Pacific Ocean},
	journal = {Journal of Sea Research},
	volume = {175},
	year = {2021},
	month = {Jan-09-2021},
	pages = {102085},
	issn = {13851101},
	doi = {10.1016/j.seares.2021.102085},
	url = {https://www.webofscience.com/wos/woscc/full-record/WOS:000687819300003?AlertId=ab9062f8-b111-4f95-a2b8-66e7afac0471\&SID=7DFRqn1B6A3SRDPNEE8},
	author = {Kim, Minkyoung and Kim, Hyung Jeek and Ko, Ara and Yoo, Chan Min and Ju, Se-Jong and Hwang, Jeomshik}
}
@article {2676,
	title = {Removal of Refractory Dissolved Organic Carbon in the Amundsen Sea, Antarctica},
	journal = {Scientific Reports},
	volume = {10},
	year = {2020},
	month = {Jan-12-2020},
	abstract = {The removal mechanism of refractory deep-ocean dissolved organic carbon (deep-DOC) is poorly understood. The Amundsen Sea Polynya (ASP) serves as a natural test basin for assessing the fate of deep-DOC when it is supplied with a large amount of fresh-DOC and exposed to strong solar radiation during the polynya opening in austral summer. We measured the radiocarbon content of DOC in the water column on the western Amundsen shelf. The radiocarbon content of DOC in the surface water of the ASP reflected higher primary production than in the region covered by sea ice. The radiocarbon measurements of DOC, taken two years apart in the ASP, were different, suggesting rapid cycling of DOC. The increase in DOC concentration was less than expected from the observed increase in radiocarbon content from those at the greatest depths. Based on a radiocarbon mass balance, we show that deep-DOC is consumed along with fresh-DOC in the ASP. Our observations imply that water circulation through the surface layer, where fresh-DOC is produced, may play an important role in global DOC cycling.},
	keywords = {CIRCUMPOLAR DEEP-WATER, cycle, DOC, glaciers, INFLOW, MATTER, pacific, phytoplankton, poc, radiocarbon},
	doi = {10.1038/s41598-020-57870-6},
	url = {http://www.nature.com/articles/s41598-020-57870-6http://www.nature.com/articles/s41598-020-57870-6.pdfhttp://www.nature.com/articles/s41598-020-57870-6.pdfhttp://www.nature.com/articles/s41598-020-57870-6},
	author = {Fang, Ling and Lee, SangHoon and Lee, Shin-Ah and Hahm, Doshik and Kim, Guebuem and Druffel, Ellen R. M. and Hwang, Jeomshik}
}
@article {2640,
	title = {Sinking particle flux and composition at three sites of different annual sea ice cover in the Amundsen Sea, Antarctica},
	journal = {Journal of Marine Systems},
	volume = {192},
	year = {2019},
	month = {Jan-04-2019},
	pages = {42 - 50},
	abstract = {This study examines the sinking particle flux and composition of samples collected at three sites in the western Amundsen Sea, Antarctica: a perennial sea-ice-covered area, the central region of the Amundsen Sea polynya, and close to the Dotson Ice Shelf within the polynya. Time series sediment traps were deployed for one year at depths of 400-500 m from February and March 2012. Observations from the three sites confirm previously reported findings that the majority of annual POC (particulate organic carbon) flux in the Amundsen Sea occurs during the austral summer, with much smaller POC fluxes during other seasons. In the perennial ice-covered area, sea ice diatoms were the dominant source of sinking particles. In this region, the summertime POC flux is similar to that in the central polynya. However, the POC flux exhibited large interannual variability, with the reduction in sea ice cover and sufficient insolation being critical to enhanced sinking POC flux. Within the Amundsen Sea polynya, the sinking POC flux was higher in the central region than near the Dotson Ice Shelf, consistent with spatial variability in primary production. The site near the Dotson Ice Shelf had the lowest contribution of diatoms to sinking particles and the smallest POC flux among the three sites.},
	keywords = {Amundsen sea, Biological pump, particulate organic carbon, Perennial ice-covered area, Polynya},
	issn = {09247963},
	doi = {10.1016/j.jmarsys.2019.01.002},
	url = {https://www.sciencedirect.com/science/article/pii/S092479631830304X},
	author = {Kim, Minkyoung and Yang, Eun J. and Kim, Dongseon and Jeong, Jin-Hyun and Kim, Hyung J. and Park, Jisoo and Jung, Jinyoung and Ducklow, Hugh W. and Lee, SangHoon and Hwang, Jeomshik}
}
@article {2630,
	title = {An Investigation of Gas Exchange and Water Circulation in the Amundsen Sea Based On Dissolved Inorganic Radiocarbon},
	journal = {Geophysical Research Letters},
	volume = {453},
	year = {2018},
	month = {Apr-11-2020},
	pages = {12,368 - 12,375},
	abstract = {We used radiocarbon isotope ratios in dissolved inorganic carbon to assess gas exchange and water circulation in the western Amundsen Sea. Radiocarbon isotope ratios indicate that Circumpolar Deep Water enters the basin along the seafloor and that the upper layer is formed through modification of this water mass. In the Amundsen Sea Polynya, radiocarbon isotope ratios of surface water are higher than those of underlying Winter Water, implying rapid absorption of atmospheric CO2. A CO2 absorption rate of 45mmol m(-2) d(-1) calculated for a site in the central polynya is higher than that near the Dotson Ice Shelf (28mmolm(-2) d(-1)). The turnover time of water in the Dotson Trough region of the western Amundsen Sea is estimated to be 10-30years, based on results from a box model and radiocarbon mass balance.

Plain Language Summary The western Amundsen Sea is experiencing raid physical changes including rapid glacial melting and declining sea ice cover. The suggested heat source is the intrusion of warm Circumpolar Deep Water (CDW) along the seafloor of the Amundsen Shelf. Therefore, understanding the behavior of the intruded CDW, especially how long it stays on the shelf, is important. Physical oceanographic studies have examined the flux of CDW onto and out of the Amundsen Shelf. However, the turnover time of water in the Amundsen Sea is still poorly understood. In this paper, we use radiocarbon isotope signature from dissolved inorganic carbon to examine how rapidly atmospheric CO2 is absorbed into the Amundsen Sea Polynya and how long the water should stay in the western Amundsen Shelf to have the observed radiocarbon isotope signature. Based on our results and the current understanding of the water circulation in the western Amundsen Sea, we found that the water sits on the Amundsen Shelf for a few decades before it moves off shelf.},
	keywords = {Amundsen sea, dissolved inorganic carbon, gas exchange, radiocarbon, water circulation},
	issn = {0094-8276},
	doi = {10.1029/2018GL079464},
	url = {http://apps.webofknowledge.com/InboundService.do?product=WOS\&Func=Frame\&DestFail=http\%3A\%2F\%2Fwww.webofknowledge.com\%3FDestParams\%3DUT\%253DWOS\%25253A000453250000030\%2526customersID\%253DAlerting\%2526smartRedirect\%253Dyes\%2526action\%253Dretrieve\%2526mode\%25},
	author = {Kim, Bumsoo and Lee, SangHoon and Kim, Minkyoung and Hahm, Doshik and Rhee, Tae Siek and Hwang, Jeomshik}
}
@article {2602,
	title = {Biological and physical controls on the flux and characteristics of sinking particles on the Northwest Atlantic margin},
	journal = {Journal of Geophysical Research: Oceans},
	volume = {122},
	year = {2017},
	month = {Jan-06-2017},
	pages = {4539 - 4553},
	abstract = {Biogenic matter characteristics and radiocarbon contents of organic carbon (OC) were examined on sinking particle samples intercepted at
three nominal depths of 1000 m, 2000 m, and 3000 m (similar to 50 m above the seafloor) during a 3 year sediment trap program on the New England slope in the Northwest Atlantic. We have sought to characterize the sources of sinking particles in the context of vertical export of biogenic particles from the overlying water column and lateral supply of resuspended sediment particles from adjacent margin sediments. High aluminum (Al) abundances and low OC radiocarbon contents indicated contributions from resuspended sediment which was greatest at 3000 m but also significant at shallower depths. The benthic source (i.e., laterally supplied resuspended sediment) of opal appears negligible based on the absence of a correlation with Al fluxes. In comparison, CaCO3 fluxes at 3000 m showed a positive correlation with Al fluxes. Benthic sources accounted for 42 similar to 63\% of the sinking particle flux based on radiocarbon mass balance and the relationship between Al flux and CaCO3 flux. Episodic pulses of Al at 3000 m were significantly correlated with the near-bottom current at a nearby hydrographic mooring site, implying the importance of current variability in lateral particle transport. However, Al fluxes at 1000 m and 2000 m were coherent but differed from those at 3000 m, implying more than one mode of lateral supply of particles in the water column.},
	doi = {10.1002/jgrc.v122.610.1002/2016JC012549},
	url = {http://doi.wiley.com/10.1002/jgrc.v122.6http://doi.wiley.com/10.1002/2016JC012549http://onlinelibrary.wiley.com/wol1/doi/10.1002/2016JC012549/fullpdfhttps://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002\%2F2016JC012549},
	author = {Hwang, Jeomshik and Manganini, Steven J. and Park, JongJin and {\c c}on, Daniel B. and Toole, John M. and Eglinton, Timothy I.}
}
@article {559,
	title = {Sinking particle flux in the sea ice zone of the Amundsen Shelf, Antarctica},
	journal = {Deep Sea Research Part I: Oceanographic Research Papers},
	volume = {101},
	year = {2015},
	note = {Ck4reTimes Cited:4Cited References Count:38},
	month = {Jul},
	pages = {110-117},
	abstract = {We have examined the flux, biogenic composition, and isotopic values of sinking particles collected by a time-series sediment trap deployed in the sea ice zone (SIZ) of the Amundsen Sea from January 2011 for 1 year. The major portion of the particle flux occurred during the austral summer in January and February when sea ice concentration was reduced to 30 \%) and a low bio-Si/POC ratio (<0.5) during the austral winter. CaCO3 content and its contribution to total particle flux was low (~6 \%) throughout the study period. Aged POC likely supplied from sediment resuspension accounted for a considerable fraction only from October to December, which was evidenced by a low radiocarbon content and relatively high (30{\textendash}50 \%) content of the non-biogenic components. When compared with POC flux inside the Amundsen Sea polynya obtained by the US Amundsen Sea Polynya International Research Expedition (ASPIRE), the POC flux integrated over the austral summer in the SIZ was virtually identical, although the maximum POC flux was approximately half that inside the Amundsen Sea polynya. This comparatively high POC flux integrated over the austral summer in the SIZ may be caused by phytoplankton blooms persisting over a longer periods and more efficient export of organic matter potentially owing to the diatom-dominant plankton community. If this observation is a general phenomenon on the Amundsen Shelf, the role of the SIZ, compared with the polynyas, need to be examined more carefully when trying to characterize the POC export in this region.},
	issn = {0967-0637},
	doi = {10.1016/j.dsr.2015.04.002},
	author = {Kim, Minkyoung and Hwang, Jeomshik and Kim, Hyung J. and Kim, Dongseon and Yang, Eun J. and Ducklow, Hugh W. and Hyoung, S. La and Lee, Sang H. and Park, Jisoo and Lee, SangHoon}
}
@article {101,
	title = {Molecular and isotopic insights into particulate organic carbon sources and dynamics in Jordan Basin, Gulf of Maine},
	journal = {Continental Shelf Research},
	volume = {68},
	year = {2013},
	pages = {15-22},
	abstract = {The carbon isotope and lipid biomarker composition of suspended particles and surface sediment was measured to examine the impact of sediment supply, redistribution and post-depositional alteration processes on organic matter cycling in the Gulf of Maine, a semi-enclosed shelf sea in the northwest Atlantic. A beam attenuation profile revealed a >50 m-thick benthic nepheloid layer (BNL) in the Jordan Basin at the time of sampling (April 2006). The relatively low radiocarbon content of suspended particulate organic carbon (POC) in the BNL indicates that up to 82\% of the POC in this layer was supplied from resuspension of sediment. The concentration of alkenones normalized to POC increased with increasing depth in the water column and was highest in the surface sediment. In contrast to these markers of surface ocean photoautotrophy, the vertical profiles for the concentration and composition of short-chain (C14{\textendash}C18) n-alkanoic acids provided evidence for enhanced heterotrophic processes near the top of the BNL. Suspended POC samples from two depths within the BNL exhibited marked differences in radiocarbon content and fatty acid composition, suggesting that biological activity and associated processes within the BNL are vertically heterogeneous.},
	issn = {0278-4343},
	doi = {10.1016/j.csr.2013.08.005},
	url = {http://www.sciencedirect.com/science/article/pii/S0278434313002653},
	author = {Hwang, Jeomshik and Montlu{\c c}on, Daniel B. and Pilskaln, Cynthia H. and Eglinton, Timothy I.}
}
@article {1991,
	title = {Blank correction for Delta 14C measurements in organic compound classes of oceanic particulate matter},
	journal = {Radiocarbon},
	volume = {47},
	year = {2005},
	note = {id: 1054},
	month = {2005},
	pages = {75-87},
	author = {Hwang, Jeomshik and Druffel, Ellen R. M.}
}
@article {2047,
	title = {Temporal variability of Delta 14C, delta13C, and C/N in sinking particulate organic matter at a deep time series station in the northeast Pacific Ocean},
	journal = {Global Biogeochemical Cycles},
	volume = {18},
	year = {2004},
	note = {id: 531},
	month = {2004},
	pages = {1-9},
	author = {Hwang, Jeomshik and Druffel, Ellen R. M. and Griffin, Sheila and L, Smith Kenneth, Jr. and Baldwin, Roberta J. and Bauer, James E.}
}
@article {2077,
	title = {Lipid-Like material as the source of the uncharacterized organic carbon in the ocean?},
	journal = {Science},
	volume = {299},
	year = {2003},
	note = {id: 530},
	month = {2003},
	pages = {881-884},
	author = {Hwang, Jeomshik and Druffel, Ellen R. M.}
}
