@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 {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}
}
