@article { ISI:000395088600004,
	title = {Anthropogenic CO2 accumulation and uptake rates in the Pacific Ocean based on changes in the C-13/C-12 of dissolved inorganic carbon},
	journal = {GLOBAL BIOGEOCHEMICAL CYCLES},
	volume = {31},
	number = {{1}},
	year = {2017},
	month = {JAN},
	pages = {59-80},
	type = {Article},
	abstract = {The anthropogenic CO2 accumulation rate for the Pacific Ocean was estimated from the decrease in C-13 of the dissolved inorganic carbon measured on six World Ocean Circulation Experiment cruises during the 1990s and repeated during Climate Variability and Predictability in the 2000s. A mean depth-integrated anthropogenic C-13 change of -8320mdecade(-1) was estimated for the basin by using the multiple linear regression approach. The largest anthropogenic C-13 decreases occurred between 40 degrees S and 60 degrees S, whereas the smallest decreases occurred in the Southern Ocean and subpolar North Pacific. A mean anthropogenic CO2 accumulation rate of 0.410.13molCm(-2)yr(-1) (0.820.26PgCyr(-1)) was determined based on observed C-13 changes and is in agreement with previous observation- and model-based estimates. The mean dissolved inorganic carbon DIC13 inventory change of -178 +/- 43 parts per thousand molm(-2)decade(-1) was primarily the result of air-sea CO2 exchange acting on the measured air-sea C-13 disequilibrium of similar to-1.2 +/- 0.1 parts per thousand. Regional differences between the DIC13 inventory change and air-sea (CO2)-C-13 flux yielded net anthropogenic CO2 uptake rates (independent of pCO(2)) that ranged from similar to 0 to 1molm(-2)yr(-1) and basin-wide mean of 1.2 +/- 1.5PgCyr(-1). High rates of surface ocean DIC increase and C-13 decrease observed in the Drake Passage (53 degrees S-60 degrees S) support above average anthropogenic CO2 accumulation since 2005. Observed C-13 changes in the Pacific Ocean indicate that ocean transport significantly impacted the anthropogenic CO2 distribution and illustrate the utility of C-13 as a tracer to unravel the processes controlling the present and future accumulation of anth ropogenic CO2 in the ocean.},
	keywords = {anthropogenic change, C-12, C-13, CO2, Pacific Ocean},
	issn = {0886-6236},
	doi = {10.1002/2016GB005460},
	author = {Quay, P. and Sonnerup, R. and Munro, D. and Sweeney, C.}
}
@article {2438,
	title = {MAGic: A Phanerozoic model for the geochemical cycling of major rock-forming components},
	journal = {American Journal of Science},
	volume = {306},
	year = {2006},
	note = {53},
	month = {Mar},
	pages = {135-190},
	abstract = {A dynamical model (MAGic) is presented that describes the elemental cycling of sedimentary materials involving sodium, potassium, calcium, magnesium, chloride, carbon, oxygen, iron, sulfur and phosphorous through much of the Phanerozoic. The model incorporates the basic reactions controlling atmospheric carbon dioxide and oxygen concentrations, continental and seafloor weathering of silicate and carbonate rocks, net ecosystem productivity, basalt-seawater exchange reactions, precipitation and diagenesis of chemical sediments and authigenic silicates, oxidation-reduction reactions involving carbon, sulfur, and iron, and subduction-decarbonation reactions. Although MAGic contains feedback and forcing functions adapted from the GEOCARB models (Berner, 1991, 1994; Berner and Kothavala, 2001), these functions are incorporated in a reservoir-reaction scheme that is considerably more detailed. Coupled reservoirs include shallow and deep cratonic silicate and carbonate rocks and sediments, seawater, atmosphere, oceanic sediments and basalts, and the shallow mantle. Model results are reasonably consistent with recently published constraints provided by fluid inclusion, isotopic, floral, and mineralogical records. We have used these results to evaluate sensitivity to uncertainties in the history of the earth-ocean-atmosphere system over the past 500 Ma: the advent of pelagic carbonate sedimentation, the importance of burial versus early diagenetic dolomite formation, the importance of reverse weathering, and the relationship of these processes to seafloor spreading rates. Results include a general pattern of dolomite abundance during periods of elevated seafloor spreading and alkalinity production, elevated atmospheric CO2 concentrations for most of the Phanerozoic similar to those predicted by GEOCARB, and covariance of seawater sulfate to calcium ratios with magnesium to calcium ratios. These trends are broadly consistent with proxies for seawater composition and the mass-age data of the rock record itself.},
	keywords = {ATMOSPHERIC CARBON-DIOXIDE, CENOZOIC EVOLUTION, Clay minerals, CO2, DOLOMITE PROBLEM, marine-sediments, REVISED MODEL, SEAWATER CHEMISTRY, SECULAR VARIATION, time},
	isbn = {0002-9599},
	doi = {10.2475/ajs.306.3.135 },
	author = {Arvidson, R. S. and Mackenzie, F. T. and Guidry, M.}
}
@article {1965,
	title = {A decrease in discharge-normalized DOC export by the Yukon River during summer through autumn},
	journal = {Geophysical Research Letters},
	volume = {32},
	year = {2005},
	note = {985cuTimes Cited:163
Cited References Count:28
},
	month = {Nov 12},
	abstract = {Climate warming is having a dramatic effect on the vegetation distribution and carbon cycling of terrestrial subarctic and arctic ecosystems. Here, we present hydrologic evidence that warming is also affecting the export of dissolved organic carbon and bicarbonate (DOC and HCO3-) at the large basin scale. In the 831,400 km(2) Yukon River basin, water discharge (Q) corrected DOC export significantly decreased during the growing season from 1978 - 80 to 2001 - 03, indicating a major shift in terrestrial to aquatic C transfer. We conclude that decreased DOC export, relative to total summer through autumn Q, results from increased flow path, residence time, and microbial mineralization of DOC in the soil active layer and groundwater. Counter to current predictions, we argue that continued warming could result in decreased DOC export to the Bering Sea and Arctic Ocean by major subarctic and arctic rivers, due to increased respiration of organic C on land.},
	keywords = {alaska, arctic-ocean, climate-change, CO2, discontinuous permafrost, dissolved organic-carbon, flux, MATTER, tundra},
	isbn = {0094-8276},
	doi = {10.1029/2005GL024413},
	url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2\&amp;SrcAuth=Alerting\&amp;SrcApp=Alerting\&amp;DestApp=WOS\&amp;DestLinkType=FullRecord;UT=WOS:000233354500009},
	author = {Striegl, R. G. and Aiken, G. R. and Dornblaser, M. M. and Raymond, P. A. and Wickland, K. P.}
}
@article {2003,
	title = {Input of particulate organic and dissolved inorganic carbon from the Amazon to the Atlantic Ocean},
	journal = {Geochemistry Geophysics Geosystems},
	volume = {6},
	year = {2005},
	note = {909pwTimes Cited:17
Cited References Count:21
},
	month = {Mar 18},
	abstract = {We report concentrations and isotope measurements (radiocarbon and stable carbon) of dissolved inorganic carbon (DIC) and suspended particulate organic carbon (POC) in waters collected from the mouth of the Amazon River and the North Brazil Current. Samples were collected in November 1991, when the Amazon hydrograph was at its annual minimum and the North Brazil Current had retroflected into the equatorial North Atlantic. The DIC D 14 C results revealed postbomb carbon in river and ocean waters, with slightly higher values at the river mouth. The low DIC delta(13)C signature of the river end-member (-11\%) demonstrates that about half of the DIC originated from the remineralization of terrestrially derived organic matter. A linear relationship between DIC and salinity indicates that DIC was mixed nearly conservatively in the transition zone from the river mouth to the open ocean, though there was a small amount (<= 10\%) of organic matter remineralization in the mesohaline region. The POC Delta(14)C values in the river mouth were markedly lower than those values from the western Amazon region (Hedges et al., 1986). We conclude that the dominant source of POC near the river mouth and in the inner Amazon plume during November 1991 was aged, resuspended material of significant terrestrial character derived from shelf sediments, while the outer plume contained mainly marine-derived POC.},
	keywords = {accumulation, amazon, C-14, carbon cycling, CO2, continental-shelf, poc, radiocarbon, river system, Sediment, total co(2), water},
	isbn = {1525-2027},
	doi = {10.1029/2004GC000842},
	author = {Druffel, E. R. M. and Bauer, J. E. and Griffin, S.}
}
@article {2049,
	title = {Characterization of Siberian Arctic coastal sediments: Implications for terrestrial organic carbon export},
	journal = {Global Biogeochemical Cycles},
	volume = {18},
	year = {2004},
	note = {806knTimes Cited:99
Cited References Count:51
},
	month = {Mar 10},
	abstract = {Surface sediments were collected during the 2000 TransArctic Expedition along the Siberian Arctic coastline, including the Ob, Yenisey, Khatanga, Lena, and Indigirka estuaries. Sediments were characterized for elemental composition (total organic carbon, TOC, black carbon, BC, and total N, as well as major and trace elements), isotopic signature (delta(13)C, delta(15)N, Delta(14)C, epsilon(Nd), Sr-87/Sr-86), and organic molecular composition to better understand river export variations over the large spatial scale of the Siberian Arctic. On average, 79 +/- 9\% of the total C in sediments was organic while 21 +/- 9\% was inorganic. BC made up 9 +/- 4\% of the TOC pool, with a general increasing trend from west to east along the Siberian coast. The combined Nd- and Sr-isotopes (epsilon(Nd) and Sr-87/Sr-86) were used to define two distinct sediment sources between east and west Siberian regions with the Khatanga River as a boundary. Data from pyrolysis-GC/MS of the sedimentary organic carbon (SOC) indicated an increase in the freshness of the organic matter from west to east on the Siberian Arctic coast, with increasing relative abundance of furfurals (polysaccharides) with respect to nitriles. Values for the delta(13)C of SOC ranged from -27.1\% (mostly terrigenous) to -23.8\%, while delta(15)N increased from east to west (3.1 to 5.2\%) with a significant correlation with C/N ratio. Values for the Delta(14)C of SOC ranged from -805 to -279\%, with a consistent trend increasing from the east (Indigirka River) to the west (Ob River). These D 14 C values corresponded to a 14 C age of 2570 +/- 30 yBP in the Ob estuary and 13,050 +/- 50 yBP in the Indigirka estuary. Most importantly, D 14 C values were significantly correlated with the ratio of BC/TOC (R-2 = 0.91, n = 6), consistent with the distribution pattern of increasing permafrost zone from the west to the east along the Siberian coast. Together, our results suggest that older OC was derived from the release of recalcitrant BC during permafrost thawing and riverbank and coastal erosion, likely enhanced by ongoing environmental changes in the northern ecosystem.},
	keywords = {arctic ocean, BLACK CARBON, climate, CO2, continental-shelf, flux, isotopic composition, lena river, MATTER, ocean, organic carbon, quantification, Sediment},
	isbn = {0886-6236},
	doi = {10.1029/2003GB002087},
	url = {http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2\&amp;SrcAuth=Alerting\&amp;SrcApp=Alerting\&amp;DestApp=WOS\&amp;DestLinkType=FullRecord;UT=WOS:000220432900001},
	author = {Guo, L. D. and Semiletov, I. and Gustafsson, O. and Ingri, J. and Andersson, P. and Dudarev, O. and White, D.}
}
@article {2083,
	title = {Penetration of anthropogenic carbon into organic particles of the deep ocean},
	journal = {Geophysical Research Letters},
	volume = {30},
	year = {2003},
	note = {709dpTimes Cited:12
Cited References Count:29
},
	month = {Jul 23},
	pages = {1744},
	abstract = {[1] In the late 1980s, bomb C-14 was present in suspended particulate organic carbon (POC) from the North Central Pacific (NCP) and Sargasso Sea ( SS) throughout most of the water column, demonstrating that deep POC had exchanged with atmospheric CO2 in the past 30 years. Upon reoccupation of these sites in 1999 and 2000, respectively, we observed that the delta(13)C values of suspended POC were lower than those measured a decade earlier. This demonstrates that anthropogenic CO2 from fossil fuel and biomass burning has penetrated a major organic matter pool in the deep ocean. Delta(14)C measured in the suspended POC showed similar or higher values in the deep Sargasso Sea and decreased values in the deep NCP compared to those measured previously. We use a box model to show that the differences in the radiocarbon results are likely due to the presence of resuspended sediment that is laterally advected from the continental margin to the deep Sargasso Sea.},
	keywords = {bomb radiocarbon, C-14, CO2, delta-c-13, MATTER, NORTH PACIFIC-OCEAN, SARGASSO SEA, Sediment, variability, water},
	isbn = {0094-8276},
	doi = {10.1029/2003GL017423},
	author = {Druffel, E. R. M. and Bauer, J. E. and Griffin, S. and Hwang, J.}
}
@article {2098,
	title = {Separating natural and bomb-produced radiocarbon in the ocean: The potential alkalinity method},
	journal = {Global Biogeochemical Cycles},
	volume = {16},
	year = {2002},
	note = {646xuTimes Cited:44
Cited References Count:35
},
	month = {Dec 3},
	abstract = {[1] The use of radiocarbon (Delta(14)C) as a tracer for oceanic processes generally requires differentiation of naturally occurring radiocarbon from the bomb component produced by atmospheric nuclear weapons testing. We present a new separation method based on the strong linear correlation between Delta(14)C and potential alkalinity. Unlike previous techniques the new algorithm is applicable at all latitudes. Additionally, the potential alkalinity method provides an estimate of surface ocean prebomb Delta(14)C concentrations. Predictions with the technique appear to be unbiased and have uncertainties which are less than previous techniques.},
	keywords = {bomb-produced radiocarbon, CO2, indian-ocean, inventory, natural radiocarbon, pacific-ocean, potential alkalinity method, radiocarbon inventory, radiocarbon separation, silicate method, thermocline, ventilation, woce},
	isbn = {0886-6236},
	doi = {10.1029/2001GB001432},
	author = {Rubin, S. I. and Key, R. M.}
}
