Buesseler Kenneth O.

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Buesseler
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Kenneth O.
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0000-0001-7362-8796

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Kinetics of thorium and particle cycling along the U.S. GEOTRACES North Atlantic Transect

2017-05 , Lerner, Paul , Marchal, Olivier , Lam, Phoebe J. , Buesseler, Ken O. , Charette, Matthew A.

The high particle reactivity of thorium has resulted in its widespread use in tracing processes impacting marine particles and their chemical constituents. The use of thorium isotopes as tracers of particle dynamics, however, largely relies on our understanding of how the element scavenges onto particles. Here, we estimate apparent rate constants of Th adsorption (k1), Th desorption (k−1), bulk particle degradation (β-1), and bulk particle sinking speed (w) along the water column at 11 open-ocean stations occupied during the GEOTRACES North Atlantic Section (GA03). First, we provide evidence that the budgets of Th isotopes and particles at these stations appear to be generally dominated by radioactive production and decay sorption reactions, particle degradation, and particle sinking. Rate parameters are then estimated by fitting a Th and particle cycling model to data of dissolved and particulate 228,230,234Th, 228Ra, particle concentrations, and 234,238U estimates based on salinity, using a nonlinear programming technique. We find that the adsorption rate constant (k1) generally decreases with depth across the section: broadly, the time scale 1/k1 averages 1.0 yr in the upper 1000 m and (1.4–1.5) yr below. A positive relationship between k1 and particle concentration (P) is found, i.e., , k1 ∝ Pb where b ≥ 1, consistent with the notion that k1 increases with the number of surface sites available for adsorption. The rate constant ratio, K = k1/(k-1 + β-1), which measures the collective influence of rate parameters on Th scavenging, averages 0.2 for most stations and most depths. We clarify the conditions under which K/P is equivalent to the distribution coefficient, KD, test that the conditions are met at the stations, and find that decreases with P, in line with a particle concentration effect (dKD/dP < 0). In contrast to the influence of colloids as envisioned by the Brownian pumping hypothesis, we provide evidence that the particle concentration effect arises from the joint effect of P on the rate constants for thorium attachment to, and detachment from, particles.

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Article

Flux of particulate elements in the North Atlantic Ocean constrained by multiple radionuclides

2018-11-22 , Hayes, Christopher T. , Black, Erin E. , Anderson, Robert F. , Baskaran, Mark , Buesseler, Ken O. , Charette, Matthew A. , Cheng, Hai , Cochran, J. Kirk , Edwards, R. Lawrence , Fitzgerald, Patrick , Lam, Phoebe J. , Lu, Yanbin , Morris, Stephanie O. , Ohnemus, Daniel C. , Pavia, Frank , Stewart, Gillian , Tang, Yi

Sinking particles strongly regulate the distribution of reactive chemical substances in the ocean, including particulate organic carbon and other elements (e.g., P, Cd, Mn, Cu, Co, Fe, Al, and 232Th). Yet, the sinking fluxes of trace elements have not been well described in the global ocean. The U.S. GEOTRACES campaign in the North Atlantic (GA03) offers the first data set in which the sinking flux of carbon and trace elements can be derived using four different radionuclide pairs (238U:234Th ;210Pb:210Po; 228Ra:228Th; and 234U:230Th) at stations co‐located with sediment trap fluxes for comparison. Particulate organic carbon, particulate P, and particulate Cd fluxes all decrease sharply with depth below the euphotic zone. Particulate Mn, Cu, and Co flux profiles display mixed behavior, some cases reflecting biotic remineralization, and other cases showing increased flux with depth. The latter may be related to either lateral input of lithogenic material or increased scavenging onto particles. Lastly, particulate Fe fluxes resemble fluxes of Al and 232Th, which all have increasing flux with depth, indicating a dominance of lithogenic flux at depth by resuspended sediment transported laterally to the study site. In comparing flux estimates derived using different isotope pairs, differences result from different timescales of integration and particle size fractionation effects. The range in flux estimates produced by different methods provides a robust constraint on the true removal fluxes, taking into consideration the independent uncertainties associated with each method. These estimates will be valuable targets for biogeochemical modeling and may also offer insight into particle sinking processes.

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Article

The GEOTRACES Intermediate Data Product 2017

2018-06-01 , Schlitzer, Reiner , Anderson, Robert F. , Dodas, Elena Masferrer , Lohan, Maeve C. , Geibert, Walter , Tagliabue, Alessandro , Bowie, Andrew R. , Jeandel, Catherine , Maldonado, Maria T. , Landing, William M. , Cockwell, Donna , Abadie, Cyril , Abouchami, Wafa , Achterberg, Eric P. , Agather, Alison , Aguliar-Islas, Ana , van Aken, Hendrik M. , Andersen, Morten , Archer, Corey , Auro, Maureen E. , Baar, Hein J. W. de , Baars, Oliver , Baker, Alex R. , Bakker, Karel , Basak, Chandranath , Baskaran, Mark , Bates, Nicholas R. , Bauch, Dorothea , van Beek, Pieter , Behrens, Melanie K. , Black, Erin E. , Bluhm, Katrin , Bopp, Laurent , Bouman, Heather , Bowman, Katlin , Bown, Johann , Boyd, Philip , Boye, Marie , Boyle, Edward A. , Branellec, Pierre , Bridgestock, Luke , Brissebrat, Guillaume , Browning, Thomas A. , Bruland, Kenneth W. , Brumsack, Hans-Jürgen , Brzezinski, Mark A. , Buck, Clifton S. , Buck, Kristen N. , Buesseler, Ken O. , Bull, Abby , Butler, Edward , Cai, Pinghe , Cámara Mor, Patricia , Cardinal, Damien , Carlson, Craig , Carrasco, Gonzalo , Casacuberta, Nuria , Casciotti, Karen L. , Castrillejo, Maxi , Chamizo, Elena , Chance, Rosie , Charette, Matthew A. , Chaves, Joaquin E. , Cheng, Hai , Chever, Fanny , Christl, Marcus , Church, Thomas M. , Closset, Ivia , Colman, Albert S. , Conway, Tim M. , Cossa, Daniel , Croot, Peter L. , Cullen, Jay T. , Cutter, Gregory A. , Daniels, Chris , Dehairs, Frank , Deng, Feifei , Dieu, Huong Thi , Duggan, Brian , Dulaquais, Gabriel , Dumousseaud, Cynthia , Echegoyen-Sanz, Yolanda , Edwards, R. Lawrence , Ellwood, Michael J. , Fahrbach, Eberhard , Fitzsimmons, Jessica N. , Flegal, A. Russell , Fleisher, Martin Q. , van de Flierdt, Tina , Frank, Martin , Friedrich, Jana , Fripiat, Francois , Fröllje, Henning , Galer, Stephen J. G. , Gamo, Toshitaka , Ganeshram, Raja S. , Garcia-Orellana, Jordi , Garcia Solsona, Ester , Gault-Ringold, Melanie , George, Ejin , Gerringa, Loes J. A. , Gilbert, Melissa , Godoy, Jose Marcus , Goldstein, Steven L. , Gonzalez, Santiago , Grissom, Karen , Hammerschmidt, Chad R. , Hartman, Alison , Hassler, Christel , Hathorne, Ed C. , Hatta, Mariko , Hawco, Nicholas J. , Hayes, Christopher T. , Heimbürger, Lars-Eric , Helgoe, Josh , Heller, Maija Iris , Henderson, Gideon M. , Henderson, Paul B. , van Heuven, Steven , Ho, Peng , Horner, Tristan J. , Hsieh, Yu-Te , Huang, Kuo-Fang , Humphreys, Matthew P. , Isshiki, Kenji , Jacquot, Jeremy E. , Janssen, David J. , Jenkins, William J. , John, Seth , Jones, Elizabeth M. , Jones, Janice L. , Kadko, David , Kayser, Rick , Kenna, Timothy C. , Khondoker, Roulin , Kim, Taejin , Kipp, Lauren , Klar, Jessica K. , Klunder, Maarten , Kretschmer, Sven , Kumamoto, Yuichiro , Laan, Patrick , Labatut, Marie , Lacan, Francois , Lam, Phoebe J. , Lambelet, Myriam , Lamborg, Carl H. , le Moigne, Frederique , Le Roy, Emilie , Lechtenfeld, Oliver J. , Lee, Jong-Mi , Lherminier, Pascale , Little, Susan , López-Lora, Mercedes , Lu, Yanbin , Masque, Pere , Mawji, Edward , McClain, Charles R. , Measures, Christopher I. , Mehic, Sanjin , Menzel Barraqueta, Jan-Lukas , Merwe, Pier van der , Middag, Rob , Mieruch, Sebastian , Milne, Angela , Minami, Tomoharu , Moffett, James W. , Moncoiffe, Gwenaelle , Moore, Willard S. , Morris, Paul J. , Morton, Peter L. , Nakaguchi, Yuzuru , Nakayama, Noriko , Niedermiller, John , Nishioka, Jun , Nishiuchi, Akira , Noble, Abigail E. , Obata, Hajime , Ober, Sven , Ohnemus, Daniel C. , van Ooijen, Jan , O'Sullivan, Jeanette , Owens, Stephanie A. , Pahnke, Katharina , Paul, Maxence , Pavia, Frank , Pena, Leopoldo D. , Peters, Brian , Planchon, Frederic , Planquette, Helene , Pradoux, Catherine , Puigcorbé, Viena , Quay, Paul D. , Queroue, Fabien , Radic, Amandine , Rauschenberg, Sara , Rehkämper, Mark , Rember, Robert , Remenyi, Tomas A. , Resing, Joseph A. , Rickli, Joerg , Rigaud, Sylvain , Rijkenberg, Micha J. A. , Rintoul, Stephen R. , Robinson, Laura F. , Roca-Martí, Montserrat , Rodellas, Valenti , Roeske, Tobias , Rolison, John M. , Rosenberg, Mark , Roshan, Saeed , Rutgers van der Loeff, Michiel M. , Ryabenko, Evgenia , Saito, Mak A. , Salt, Lesley , Sanial, Virginie , Sarthou, Geraldine , Schallenberg, Christina , Schauer, Ursula , Scher, Howie , Schlosser, Christian , Schnetger, Bernhard , Scott, Peter M. , Sedwick, Peter N. , Semiletov, Igor P. , Shelley, Rachel U. , Sherrell, Robert M. , Shiller, Alan M. , Sigman, Daniel M. , Singh, Sunil Kumar , Slagter, Hans , Slater, Emma , Smethie, William M. , Snaith, Helen , Sohrin, Yoshiki , Sohst, Bettina M. , Sonke, Jeroen E. , Speich, Sabrina , Steinfeldt, Reiner , Stewart, Gillian , Stichel, Torben , Stirling, Claudine H. , Stutsman, Johnny , Swarr, Gretchen J. , Swift, James H. , Thomas, Alexander , Thorne, Kay , Till, Claire P. , Till, Ralph , Townsend, Ashley T. , Townsend, Emily , Tuerena, Robyn , Twining, Benjamin S. , Vance, Derek , Velazquez, Sue , Venchiarutti, Celia , Villa-Alfageme, Maria , Vivancos, Sebastian M. , Voelker, Antje H. L. , Wake, Bronwyn , Warner, Mark J. , Watson, Ros , van Weerlee, Evaline , Weigand, M. Alexandra , Weinstein, Yishai , Weiss, Dominik , Wisotzki, Andreas , Woodward, E. Malcolm S. , Wu, Jingfeng , Wu, Yingzhe , Wuttig, Kathrin , Wyatt, Neil , Xiang, Yang , Xie, Ruifang C. , Xue, Zichen , Yoshikawa, Hisayuki , Zhang, Jing , Zhang, Pu , Zhao, Ye , Zheng, Linjie , Zheng, Xin-Yuan , Zieringer, Moritz , Zimmer, Louise A. , Ziveri, Patrizia , Zunino, Patricia , Zurbrick, Cheryl

The GEOTRACES Intermediate Data Product 2017 (IDP2017) is the second publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2016. The IDP2017 includes data from the Atlantic, Pacific, Arctic, Southern and Indian oceans, with about twice the data volume of the previous IDP2014. For the first time, the IDP2017 contains data for a large suite of biogeochemical parameters as well as aerosol and rain data characterising atmospheric trace element and isotope (TEI) sources. The TEI data in the IDP2017 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at crossover stations. The IDP2017 consists of two parts: (1) a compilation of digital data for more than 450 TEIs as well as standard hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing an on-line atlas that includes more than 590 section plots and 130 animated 3D scenes. The digital data are provided in several formats, including ASCII, Excel spreadsheet, netCDF, and Ocean Data View collection. Users can download the full data packages or make their own custom selections with a new on-line data extraction service. In addition to the actual data values, the IDP2017 also contains data quality flags and 1-σ data error values where available. Quality flags and error values are useful for data filtering and for statistical analysis. Metadata about data originators, analytical methods and original publications related to the data are linked in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2017 as section plots and rotating 3D scenes. The basin-wide 3D scenes combine data from many cruises and provide quick overviews of large-scale tracer distributions. These 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of tracer plumes near ocean margins or along ridges. The IDP2017 is the result of a truly international effort involving 326 researchers from 25 countries. This publication provides the critical reference for unpublished data, as well as for studies that make use of a large cross-section of data from the IDP2017. This article is part of a special issue entitled: Conway GEOTRACES - edited by Tim M. Conway, Tristan Horner, Yves Plancherel, and Aridane G. González.

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Preprint

Testing models of thorium and particle cycling in the ocean using data from station GT11-22 of the U.S. GEOTRACES North Atlantic section

2016-03-31 , Lerner, Paul , Marchal, Olivier , Lam, Phoebe J. , Anderson, Robert F. , Buesseler, Ken O. , Charette, Matthew A. , Edwards, R. Lawrence , Hayes, Christopher T. , Huang, Kuo-Fang , Lu, Yanbin , Robinson, Laura F. , Solow, Andrew R.

Thorium is a highly particle-reactive element that possesses different measurable radio-isotopes in seawater, with well-constrained production rates and very distinct half-lives. As a result, Th has emerged as a key tracer for the cycling of marine particles and of their chemical constituents, including particulate organic carbon. Here two different versions of a model of Th and particle cycling in the ocean are tested using an unprecedented data set from station GT11-22 of the U.S. GEOTRACES North Atlantic Section: (i) 21 228;230;234Th activities of dissolved and particulate fractions, (ii) 228Ra activities, (iii) 234;238U activities estimated from salinity data and an assumed 234U/238U ratio, and (iv) particle concentrations, below a depth of 125 m. The two model versions assume a single class of particles but rely on different assumptions about the rate parameters for sorption reactions and particle processes: a first version (V1) assumes vertically uniform parameters (a popular description), whereas the second (V2) does not. Both versions are tested by fitting to the GT11-22 data using generalized nonlinear least squares and by analyzing residuals normalized to the data errors. We find that model V2 displays a significantly better fit to the data than model V1. Thus, the mere allowance of vertical variations in the rate parameters can lead to a significantly better fit to the data, without the need to modify the structure or add any new processes to the model. To understand how the better fit is achieved we consider two parameters, K = k1=(k-1 + β-1) and K/P, where k1 is the adsorption rate constant, k-1 the desorption rate constant, β-1 the remineralization rate constant, and P the particle concentration. We find that the rate constant ratio K is large (≥0.2) in the upper 1000 m and decreases to a nearly uniform value of ca. 0.12 below 2000 m, implying that the specific rate at which Th attaches to particles relative to that at which it is released from particles is higher in the upper ocean than in the deep ocean. In contrast, K/P increases with depth below 500 m. The parameters K and K/P display significant positive and negative monotonic relationship with P, respectively, which is collectively consistent with a particle concentration effect.

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Article

Contrasting biogeochemical cycles of cobalt in the surface western Atlantic Ocean

2014-12-05 , Dulaquais, Gabriel , Boye, Marie , Middag, Rob , Owens, Stephanie A. , Puigcorbe, Viena , Buesseler, Ken O. , Masqué, Pere , Baar, Hein J. W. de , Carton, Xavier

Dissolved cobalt (DCo; <0.2 µm; 14 to 93 pM) and the apparent particulate cobalt (PCo; >0.2 µm; <1 to 15 pM) were determined in the upper water column (<1000 m) of the western Atlantic Ocean along the GEOTRACES-A02 section (64°N to 50°S). The lowest DCo concentrations, typical of a nutrient-type distribution were observed in surface waters of the subtropical domains. Strong linear relationships between DCo and phosphate (P) as well as meridional gradients of decreasing DCo from high latitudes were characterized and both linked to the Co biological requirement. External sources such as the Amazon and the atmospheric deposition were found to contribute significantly (>10%) to the DCo stock of the mixed layer in the equatorial and north subtropical domains. Biotic and abiotic processes as well as the physical terms involved in the biogeochemical cycle of Co were defined and estimated. This allowed establishing the first global budget of DCo for the upper 100 m in the western Atlantic. The biological DCo uptake flux was the dominant sink along the section, as reflected by the overall nutrient-type behavior of DCo. The regeneration varied widely within the different biogeochemical domains, accounting for 10% of the DCo-uptake rate in the subarctic gyre and for up to 85% in southern subtropical domain. These findings demonstrated that the regeneration is likely the prevailing source of DCo in the surface waters of the western Atlantic, except in the subpolar domains where physically driven sources can sustain the DCo biological requirement.

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The GEOTRACES Intermediate Data Product 2014

2015-04-16 , Mawji, Edward , Schlitzer, Reiner , Dodas, Elena Masferrer , Abadie, Cyril , Abouchami, Wafa , Anderson, Robert F. , Baars, Oliver , Bakker, Karel , Baskaran, Mark , Bates, Nicholas R. , Bluhm, Katrin , Bowie, Andrew R. , Bown, Johann , Boye, Marie , Marie, Edward A. , Branellec, Pierre , Bruland, Kenneth W. , Brzezinski, Mark A. , Bucciarelli, Eva , Buesseler, Ken O. , Butler, Edward , Cai, Pinghe , Cardinal, Damien , Casciotti, Karen L. , Chaves, Joaquin E. , Cheng, Hai , Chever, Fanny , Church, Thomas M. , Colman, Albert S. , Conway, Tim M. , Croot, Peter L. , Cutter, Gregory A. , Baar, Hein J. W. de , de Souza, Gregory F. , Dehairs, Frank , Deng, Feifei , Dieu, Huong Thi , Dulaquais, Gabriel , Echegoyen-Sanz, Yolanda , Edwards, R. Lawrence , Fahrbach, Eberhard , Fitzsimmons, Jessica N. , Fleisher, Martin Q. , Frank, Martin , Friedrich, Jana , Fripiat, Francois , Galer, Stephen J. G. , Gamo, Toshitaka , Garcia Solsona, Ester , Gerringa, Loes J. A. , Godoy, Jose Marcus , Gonzalez, Santiago , Grossteffan, Emilie , Hatta, Mariko , Hayes, Christopher T. , Heller, Maija Iris , Henderson, Gideon M. , Huang, Kuo-Fang , Jeandel, Catherine , Jenkins, William J. , John, Seth G. , Kenna, Timothy C. , Klunder, Maarten , Kretschmer, Sven , Kumamoto, Yuichiro , Laan, Patrick , Labatut, Marie , Lacan, Francois , Lam, Phoebe J. , Lannuzel, Delphine , le Moigne, Frederique , Lechtenfeld, Oliver J. , Lohan, Maeve C. , Lu, Yanbin , Masqué, Pere , McClain, Charles R. , Measures, Christopher I. , Middag, Rob , Moffett, James W. , Navidad, Alicia , Nishioka, Jun , Noble, Abigail E. , Obata, Hajime , Ohnemus, Daniel C. , Owens, Stephanie A. , Planchon, Frederic , Pradoux, Catherine , Puigcorbe, Viena , Quay, Paul D. , Radic, Amandine , Rehkamper, Mark , Remenyi, Tomas A. , Rijkenberg, Micha J. A. , Rintoul, Stephen R. , Robinson, Laura F. , Roeske, Tobias , Rosenberg, Mark , Rutgers van der Loeff, Michiel M. , Ryabenko, Evgenia , Saito, Mak A. , Roshan, Saeed , Salt, Lesley , Sarthou, Geraldine , Schauer, Ursula , Scott, Peter M. , Sedwick, Peter N. , Sha, Lijuan , Shiller, Alan M. , Sigman, Daniel M. , Smethie, William M. , Smith, Geoffrey J. , Sohrin, Yoshiki , Speich, Sabrina , Stichel, Torben , Stutsman, Johnny , Swift, James H. , Tagliabue, Alessandro , Thomas, Alexander L. , Tsunogai, Urumu , Twining, Benjamin S. , van Aken, Hendrik M. , van Heuven, Steven , van Ooijen, Jan , van Weerlee, Evaline , Venchiarutti, Celia , Voelker, Antje H. L. , Wake, Bronwyn , Warner, Mark J. , Woodward, E. Malcolm S. , Wu, Jingfeng , Wyatt, Neil , Yoshikawa, Hisayuki , Zheng, Xin-Yuan , Xue, Zichen , Zieringer, Moritz , Zimmer, Louise A.

The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEIs) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in the IDP2014 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at cross-over stations. The digital data are provided in several formats, including ASCII spreadsheet, Excel spreadsheet, netCDF, and Ocean Data View collection. In addition to the actual data values the IDP2014 also contains data quality flags and 1-σ data error values where available. Quality flags and error values are useful for data filtering. Metadata about data originators, analytical methods and original publications related to the data are linked to the data in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2014 data providing section plots and a new kind of animated 3D scenes. The basin-wide 3D scenes allow for viewing of data from many cruises at the same time, thereby providing quick overviews of large-scale tracer distributions. In addition, the 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of observed tracer plumes, as well as for making inferences about controlling processes.

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Ironing out Fe residence time in the dynamic upper ocean

2020-08-26 , Black, Erin E. , Kienast, Stephanie S. , Lemaitre, Nolwenn , Lam, Phoebe J. , Anderson, Robert F. , Planquette, Helene , Planchon, Frederic , Buesseler, Ken O.

Although iron availability has been shown to limit ocean productivity and influence marine carbon cycling, the rates of processes driving iron's removal and retention in the upper ocean are poorly constrained. Using 234Th‐ and sediment‐trap data, most of which were collected through international GEOTRACES efforts, we perform an unprecedented observation‐based assessment of iron export from and residence time in the upper ocean. The majority of these new residence time estimates for total iron in the surface ocean (0–250 m) fall between 10 and 100 days. The upper ocean residence time of dissolved iron, on the other hand, varies and cycles on sub‐annual to annual timescales. Collectively, these residence times are shorter than previously thought, and the rates and timescales presented here will contribute to ongoing efforts to integrate iron into global biogeochemical models predicting climate and carbon dioxide sequestration in the ocean in the 21st century and beyond.

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