@article {2923,
	title = {Carbon Isotopic and Lithologic Constraints on the Sources and Cycling of Inorganic Carbon in Four Large Rivers in China: Yangtze, Yellow, Pearl, and Heilongjiang},
	journal = {Journal of Geophysical Research: Biogeosciences},
	volume = {126},
	year = {2021},
	month = {Jan-02-2021},
	abstract = {Transport of terrigenous carbon by rivers has been affected extensively by climate change and anthropogenic activities in China over the last few decades. Here, we present results on carbon isotopes (C-13, C-14) of dissolved and particulate inorganic carbon (DIC and PIC) and combined with major lithologic ions measured in the four largest rivers in China, namely, the Yangtze, Yellow, Pearl, and Heilongjiang rivers, to reveal the sources and transport of terrigenous inorganic carbon in the rivers. The DIC concentrations showed large variations in the four rivers and ranged from 253 to 3,122 mu M. The Yangtze, Yellow and Pearl rivers transported high DIC contents that had low Delta C-14 values of millennium-aged DIC and very old PIC; however, the Heilongjiang River presented a lower DIC concentration with much younger C-14 ages than the global average (1,100 mu M). The strong correlations between the DIC isotope values and major lithological ions (Ca2+ and Mg2+) suggest that chemical weathering played important but variable roles in controlling the production and fate of DIC in the rivers. Using dual isotopes and the MixSIAR model, we calculated that the chemical weathering of carbonate rocks contributed 95 +/- 5\% of the riverine DIC to the headwater of the Yangtze River while silicate rock weathering and riverine organic matter respiration contributed 62 +/- 25\% and 5 +/- 5\% of the DIC in the middle and lower reaches of the river, respectively. In contrast, chemical weathering of silicate rocks contributed the dominant fraction of DIC in the Yellow (55 +/- 17\%), Pearl (61 +/- 20\%) and Heilongjiang (83 +/- 29\%) rivers.},
	keywords = {Carbon cycle, Chemical weathering, inorganic carbon in large rivers, radiocarbon, stable carbon isotope},
	issn = {2169-8953},
	doi = {10.1029/2020JG005901},
	url = {https://apps.webofknowledge.com/InboundService.do?product=WOS\&Func=Frame\&DestFail=http\%3A\%2F\%2Fwww.webofknowledge.com\&SrcApp=search\&SrcAuth=Alerting\&SID=7EQ3XpZtZiWye3DFos4\&customersID=Alerting\&mode=FullRecord\&IsProductCode=Yes\&AlertId=4d48b20a-7d27-4fa2-},
	author = {Shan, Sen and Luo, Chunle and Qi, Yuanzhi and Cai, Wei-Jun and Sun, Shuwen and Fan, Di and Wang, Xuchen}
}
@article {2914,
	title = {Carbon cycling in the deep Mariana Trench in the western north Pacific Ocean: Insights from radiocarbon proxy data},
	journal = {Deep Sea Research Part I: Oceanographic Research Papers},
	volume = {164},
	year = {2020},
	month = {Jan-10-2020},
	pages = {103370},
	abstract = {The Mariana Trench in the western North Pacific (NP) contains the deepest (11,000 m) point in the ocean and thus remains the least explored environment. Carbon cycling in the deep Mariana Trench is largely unknown and remains a curious mystery. Here, we report radiocarbon (Delta C-14) and stable carbon isotope (delta C-13) compositions of dissolved inorganic and organic carbon (DIC and DOC) and sinking particulate organic carbon (POC) for samples collected at 2000 m, 4000 m and 6000 m from the Mariana Trench in the western NP. DOC had much lower Delta C-14 values (-189 parts per thousand to -538 parts per thousand) than DIC (38 parts per thousand to -236 parts per thousand) and POC (11 parts per thousand-38 parts per thousand) at the same depths, indicating the different cycling processes and time scales of different carbon pools. The C-14 ages of DOC were approximately 1700 years and 4400 years older than those of DIC in the surface (2 m) and deep (10,000 m) waters of the Mariana Trench. Both DOC and DIC Delta C-14 values at hadal depths (>6000 m) in the trench are comparable to values at other sites in the deep NP, suggesting that water movement and mixing at hadal depths in the Mariana Trench are active and follow the deep-water circulation patterns of the NP. POC fluxes at the three deep depths showed large variations, but their modern Delta C-14 values indicate that the effective biological pump that drives fresh surface-produced particles to sink rapidly to deep depths in the trench could provide essential food sources for microbial and benthic communities living in an extremely harsh environment of the Mariana Trench.},
	keywords = {carbon cycling, Mariana trench, North pacific ocean, Particle flux, radiocarbon, stable carbon isotope},
	issn = {09670637},
	doi = {10.1016/j.dsr.2020.103370},
	url = {https://apps.webofknowledge.com/InboundService.do?product=WOS\&Func=Frame\&DestFail=http\%3A\%2F\%2Fwww.webofknowledge.com\&SrcApp=search\&SrcAuth=Alerting\&SID=5FcsGoXKXNO2xQfU7KW\&customersID=Alerting\&mode=FullRecord\&IsProductCode=Yes\&AlertId=4d48b20a-7d27-4fa2-},
	author = {Shan, Sen and Qi, Yuanzhi and Tian, Jiwei and Wang, Xuchen and Luo, Chunle and Zhou, Chun and Zhang, Xiao-Hua and Xin, Yu and Wang, Yonghong}
}
@article {2915,
	title = {Dissolved black carbon is not likely a significant refractory organic carbon pool in rivers and oceansAbstract},
	journal = {Nature Communications},
	volume = {11},
	year = {2020},
	month = {Jan-12-2020},
	abstract = {Rivers are the major carriers of dissolved black carbon (DBC) from land to ocean; the sources of DBC during its continuous transformation and cycling in the ocean, however, are not well characterized. Here, we present new carbon isotope data for DBC in four large and two small mountainous rivers, the Yangtze and Yellow river estuaries, the East China Sea and the North Pacific Ocean. We found that the carbon isotope signatures of DBC are relatively homogeneous, and the DBC C-14 ages in rivers are predominantly young and increase during continuous transport and cycling in the ocean. The results of charcoal leaching experiments indicate that DBC is released from charcoal and degraded by bacteria. Our study suggests that riverine DBC is labile and respired during transport and mixing into the ocean and that residual DBC is cycled and aged on the same time scales as bulk DOC in the ocean. Black carbon is a recalcitrant byproduct of biomass burning that ultimately accumulates in oceanic sinks. Here the authors assessed the sources and cycling of dissolved black carbon in rivers and oceans, finding that oceanic pools are cycled and aged on the same time scales as dissolved organic carbon.},
	keywords = {Changjiang, cycle, flux, HUANGHE RIVERS, level, particulate, quantification, radiocarbon, sea},
	doi = {10.1038/s41467-020-18808-8},
	url = {http://www.nature.com/articles/s41467-020-18808-8http://www.nature.com/articles/s41467-020-18808-8.pdfhttp://www.nature.com/articles/s41467-020-18808-8.pdfhttp://www.nature.com/articles/s41467-020-18808-8},
	author = {Qi, Yuanzhi and Fu, Wenjing and Tian, Jiwei and Luo, Chunle and Shan, Sen and Sun, Shuwen and Ren, Peng and Zhang, Hongmei and Liu, Jiwen and Zhang, Xiaohua and Wang, Xuchen}
}
@article { ISI:000375679100005,
	title = {Carbon isotopic (C-14 and C-13) characterization of fossil-fuel derived dissolved organic carbon in wet precipitation in Shandong Province, China},
	journal = {JOURNAL OF ATMOSPHERIC CHEMISTRY},
	volume = {73},
	number = {{2}},
	year = {2016},
	month = {JUN},
	pages = {207-221},
	type = {Article},
	abstract = {We present results from a 1-year study of radiocarbon and stable carbon isotope measurement of dissolved organic carbon (DOC) of wet precipitation samples collected in the Shandong province of China. A total of 32 rainfall and 4 snow samples were collected from two coastal cities (Qingdao and Yantai) and one inland site (Taian) during 2014. Concentrations of DOC in the rainwater and snow samples varied widely from 28 to 616 mu M. In general, rainwater originating from marine sources had relatively low DOC concentrations compared with continentally generated precipitation. Values of delta C-13-DOC and Delta C-14-DOC in the snow and rainwater ranged from -19.0 to -29.4 \% and -23 to -494 \%, with corresponding radiocarbon ages of 125 to 5410 years before present. The dominant DOC in the wet precipitation had a relatively old C-14 age (average 2841 years) and a depleted C-13 value (average -24.4 Years), indicating the mixing of contemporary organic carbon with C-14-depleted fossil fuel-derived soluble organic carbon in the atmosphere. Using a dual isotopic two-endmember model, we calculate that 7 \% to 52 \% of DOC in the snow and rainfall originated from fossil fuels. It is estimated that the flux of DOC in continental rainfall of China is 23 x 10(12) g C yr(-1) and of this, 7.1 x 10(12) g C yr(-1) could be fossil-fuel OC. On a global scale, the DOC flux in rainfall is estimated to be 357 Tg C yr(-1), and 110 Tg C yr(-1) could be fossil fuel-derived. Our study demonstrates that wet precipitation is an important removal process for old fossil fuel carbon from the atmosphere. This removal mechanism could play an important role in the carbon cycle, especially for the anthropogenically derived fraction, and it should be taken into consideration in global carbon cycle models.},
	keywords = {Atmospheric pollution, Fossil fuelemission, organic carbon, radiocarbon, Wet precipitation},
	issn = {0167-7764},
	doi = {10.1007/s10874-015-9323-3},
	author = {Wang, Xuchen and Ge, Tiantian and Xu, Caili and Xue, Yuejun and Luo, Chunle}
}
@article { ISI:000389875700006,
	title = {DISSOLVED INORGANIC RADIOCARBON IN THE NORTHWEST PACIFIC CONTINENTAL MARGIN},
	journal = {RADIOCARBON},
	volume = {58},
	number = {{3}},
	year = {2016},
	month = {SEP},
	pages = {517-529},
	type = {Article},
	abstract = {This article presents a modified method for extraction of dissolved inorganic carbon (DIC) from seawater for radiocarbon measurement by accelerator mass spectrometry (AMS). Standard tests indicate that the extraction efficiencies of DIC are >96\%, and the respective precisions of. Delta C-14-DIC and delta C-13-DIC analyses are 6\% and 0.1\% or better. Using the method, we report. Delta C-14-DIC profiles collected from the shelf and slope in the East China Sea (ECS) of the northwest Pacific Ocean. Both the DIC concentration and. Delta C-14-DIC in the shelf and slope regions seem primarily affected by the Kuroshio Current. It is estimated that 54-65\% of the bottom water in the shelf region could be from the intrusion of Kuroshio intermediate water, which carries a high concentration and low. Delta C-14 values of DIC, and which influenced the DIC and its Delta C-14 signature on the shelf. Compared with the. Delta C-14-DIC profiles at other sites in the northwest Pacific reported previously, it appears that the. Delta C-14-DIC distributions are mainly controlled by the major oceanic currents in the region, and large variations in. Delta C-14-DIC occurred mostly in the upper 800m of the water column. The similarity of. Delta C-14-DIC at depth suggests that the deep-water circulation patterns have been relatively stable in the northwest Pacific Ocean in the last 20 yr.},
	keywords = {continental margin, dissolved inorganic carbon, East China Sea, radiocarbon, stable carbon isotope},
	issn = {0033-8222},
	doi = {10.1017/RDC.2016.23},
	author = {Ge, Tiantian and Wang, Xuchen and Zhang, Jing and Luo, Chunle and Xue, Yuejun}
}
