@article {614,
	title = {Sources of CO2 evasion from two subtropical rivers in North America},
	journal = {Biogeochemistry},
	volume = {100},
	year = {2010},
	note = {646uoTimes Cited:17Cited References Count:55},
	month = {Sep},
	pages = {211-225},
	abstract = {We directly measured the partial pressure of dissolved CO2 (pCO(2)) in two humid subtropical rivers in coastal Texas, one highly urbanized (Buffalo Bayou) and one relatively undeveloped (Spring Creek), and analyzed carbon isotopic signatures (Delta C-14 and delta C-13) of riverine dissolved inorganic carbon (DIC) to determine carbon sources sustaining river respiration. Both rivers were highly supersaturated with CO2 at all study sites and on all dates sampled from June 2007 to February 2009. Mean riverine pCO(2) values are 3,052 +/- A 1,364 and 4,702 +/- A 1,980 mu atm for Buffalo Bayou and Spring Creek, respectively. Calculated CO2 emission fluxes per ha of water surface area from these rivers are intermediate between those in tropical and temperate rivers, indicating that globally, humid subtropical rivers may be a significant source of atmospheric CO2. Carbon isotopic signatures revealed that CO2 supersaturation is supported by different carbon sources for the two rivers. In the relatively undeveloped river (Spring Creek), young terrestrial organic matter (OM) is the predominant C source fueling river heterotrophic respiration. In the highly urbanized river (Buffalo Bayou), the high concentration of riverine CO2 is additionally supported by dissolution of CaCO3 likely from pedogenic carbonate, and crushed limestone/dolomite and oyster shells imbedded in old roads in the watershed. Because urban sources of acidity can include HNO3 and H2SO4, whether the limestone/dolomite and shells used by humans act as a net sink or source of atmospheric CO2 needs further study.},
	issn = {0168-2563},
	doi = {10.1007/s10533-010-9417-6},
	author = {Zeng, F. W. and Masiello, C. A.}
}
@article {668,
	title = {A Critical Evaluation of Interlaboratory Data on Total, Elemental, and Isotopic Carbon in the Carbonaceous Particle Reference Material, NIST SRM 1649a},
	journal = {J Res Natl Inst Stand Technol},
	volume = {107},
	year = {2002},
	note = {Currie, L ABenner, B A JrKessler, J DKlinedinst, D BKlouda, G AMarolf, J VSlater, J FWise, S ACachier, HCary, RChow, J CWatson, JDruffel, E R MMasiello, C AEglinton, T IPearson, AReddy, C MGustafsson, OQuinn, J GHartmann, P CHedges, J IPrentice, K MKirchstetter, T WNovakow, TPuxbaum, HSchmid, Heng2002/01/01 00:00J Res Natl Inst Stand Technol. 2002 Jun 1;107(3):279-98. doi: 10.6028/jres.107.022. Print 2002 May-Jun.},
	month = {May-Jun},
	pages = {279-98},
	abstract = {Because of increased interest in the marine and atmospheric sciences in elemental carbon (EC), or black carbon (BC) or soot carbon (SC), and because of the difficulties in analyzing or even defining this pervasive component of particulate carbon, it has become quite important to have appropriate reference materials for intercomparison and quality control. The NIST "urban dust" Standard Reference Material((R)) SRM 1649a is useful in this respect, in part because it comprises a considerable array of inorganic and organic species, and because it exhibits a large degree of ((14)C) isotopic heterogeneity, with biomass carbon source contributions ranging from about 2 \% (essentially fossil aliphatic fraction) to about 32 \% (polar fraction). A primary purpose of this report is to provide documentation for the new isotopic and chemical particulate carbon data for the most recent (31 Jan. 2001) SRM 1649a Certificate of Analysis. Supporting this is a critical review of underlying international intercomparison data and methodologies, provided by 18 teams of analytical experts from 11 institutions. Key results of the intercomparison are: (1) a new, Certified Value for total carbon (TC) in SRM 1649a; (2) (14)C Reference Values for total carbon and a number of organic species, including for the first time 8 individual PAHs; and (3) elemental carbon (EC) Information Values derived from 13 analytical methods applied to this component. Results for elemental carbon, which comprised a special focus of the intercomparison, were quite diverse, reflecting the confounding of methodological-matrix artifacts, and methods that tended to probe more or less refractory regions of this universal, but ill-defined product of incomplete combustion. Availability of both chemical and (14)C speciation data for SRM 1649a holds great promise for improved analytical insight through comparative analysis (e.g., fossil/biomass partition in EC compared to PAH), and through application of the principle of isotopic mass balance.},
	issn = {1044-677X (Linking)},
	doi = {10.6028/jres.107.022},
	author = {Currie, L. A. and Benner, B. A., Jr. and Kessler, J. D. and Klinedinst, D. B. and Klouda, G. A. and Marolf, J. V. and Slater, J. F. and Wise, S. A. and Cachier, H. and Cary, R. and Chow, J. C. and Watson, J. and Druffel, E. R. and Masiello, C. A. and Eglinton, T. I. and Pearson, A. and Reddy, C. M. and Gustafsson, O. and Quinn, J. G. and Hartmann, P. C. and Hedges, J. I. and Prentice, K. M. and Kirchstetter, T. W. and Novakow, T. and Puxbaum, H. and Schmid, H.}
}
@article {770,
	title = {Carbon isotope geochemistry of the Santa Clara River},
	journal = {Global Biogeochemical Cycles},
	volume = {15},
	year = {2001},
	note = {441mbTimes Cited:116Cited References Count:34},
	month = {Jun},
	pages = {407-416},
	abstract = {The Santa Clara River is a prototypical small mountainous river, with a headwater height greater than 1000 m and a basin area smaller than 10,000 m(2). Although individual small mountainous rivers export trivial amounts of sediment and carbon to the ocean, as a group these rivers may export a major fraction las much as 50\%) of the total global river sediment flux [Milliman and Syvitski, 1992], making their geochemistry relevant the study of the ocean{\textquoteright}s carbon cycle. In addition, many small rivers export sediment in a few high flux events, causing massive, sporadic discharge of carbon onto coastal shelves, discharge conditions very different from those of large rivers. This class of rivers is an end-member of the river-ocean carbon exchange system, opposite the Earth{\textquoteright}s largest river, the Amazon. The carbon mass and isotopic properties of the Santa Clara River are significantly different from previously studied large rivers. During the 1997-1998 winter, all Santa Clara carbon pools were old, with flux-weighted average Delta (14)C values of -428 +/- 76 parts per thousand for particulate organic carbon, -73 +/- 31 parts per thousand for dissolved organic carbon, and -644 +/- 58 parts per thousand for black carbon. The age of exported carbon is primarily due to the deep erosion of old soils and not to inclusion of fossil fuel carbon. Additionally, the delta (13)C signatures of exported carbon pools were high relative to terrestrial carbon, bearing a signature quite similar to marine carbon (average particulate organic carbon (POC) delta (13)C = -22.2 +/- 0.8 parts per thousand). The Santa Clara{\textquoteright}s estuary is small and drains onto the narrow eastern Pacific coastal margin, exporting this old soil organic matter directly into the ocean. If the Santa Clara export patterns are representative of this class of rivers, they may be a significant source of refractory terrestrial carbon to the ocean.},
	issn = {0886-6236},
	doi = {10.1029/2000gb001290},
	author = {Masiello, C. A. and Druffel, E. R. M.}
}
@article {800,
	title = {Physical controls on dissolved inorganic radiocarbon variability in the California Current},
	journal = {Deep-Sea Research Part Ii-Topical Studies in Oceanography},
	volume = {45},
	year = {1998},
	note = {102ttTimes Cited:21Cited References Count:43},
	pages = {617-642},
	abstract = {We present depth profiles of Delta(14)C and delta(13)C Of dissolved inorganic carbon (DIC) at Station M in the Eastern North Pacific. Several seasonal profiles are presented for the time period between 1991 and 1996. Comparison with GEOSECS data clearly shows changes in ocean radiocarbon profiles since 1973. The Delta(14)C Of DIC shows the most variability at depths of 450, 85, and 25 m, and the lowest variability at depths of 1600 and 2500 m. The largest variability in DIC Delta(14)C occurs at 450 m, a depth marked by large fluctuations in the radiocarbon signatures of the source waters. The likely controls of DIC Delta(14)C variability are physical changes in the circulation of the California Current System. A simple two-box model is used to show the importance of wind driven mixing at the surface. We discuss the likely effects of mesoscale eddies and ENSO on the DIC Delta(14)C values at this site. We also show that remineralization of organic carbon (dissolved or particulate) is not responsible for the variability in the Delta(14)C Of DIC observed at Station M. (C) 1998 Elsevier Science Ltd. All rights reserved.},
	issn = {0967-0645},
	doi = {10.1016/S0967-0645(97)00096-9},
	author = {Masiello, C. A. and Druffel, E. R. M. and Bauer, J. E.}
}
