Altabet, M.A. 1988. Variations in nitrogen isotopic composition between sinking and suspended particles: Implications for nitrogen cycling and particle transformation in the open ocean. Deep Sea Research Part I 35:535–554, https://doi.org/10.1016/0198-0149(88)90130-6.
Altabet, M.A. 2001. Nitrogen isotopic evidence for micronutrient control of fractional NO3– utilization in the equatorial Pacific. Limnology and Oceanography 46(2):368–380, https://doi.org/10.4319/lo.2001.46.2.0368.
Altieri, K.E., S.E. Fawcett, and M.G. Hastings. 2021. Reactive nitrogen cycling in the atmosphere and ocean. Annual Review of Earth and Planetary Sciences 49(1):523–550, https://doi.org/10.1146/annurev-earth-083120-052147.
Arrigo, K.R. 2005. Marine microorganisms and global nutrient cycles. Nature 437(7057):349–355, https://doi.org/10.1038/nature04159.
Babbin, A.R., R.G. Keil, A.H. Devol, and B.B. Ward. 2014. Organic matter stoichiometry, flux, and oxygen control nitrogen loss in the ocean. Science 344(6182):406–408, https://doi.org/10.1126/science.1248364.
Babbin, A.R., C. Buchwald, F.M.M. Morel, S.D. Wankel, and B.B. Ward. 2020. Nitrite oxidation exceeds reduction and fixed nitrogen loss in anoxic Pacific waters. Marine Chemistry 224:103814, https://doi.org/10.1016/j.marchem.2020.103814.
Beck, A.J., Y. Tsukamoto, A. Tovar-Sanchez, M. Huerta-Diaz, H.J. Bokuniewicz, and S.A. Sanudo-Wilhelmy. 2007. Importance of geochemical transformations in determining submarine groundwater discharge-derived trace metal and nutrient fluxes. Applied Geochemistry 22(2):477–490, https://doi.org/10.1016/j.apgeochem.2006.10.005.
Beck, A.J., J.K. Cochran, and S.A. Sañudo-Wilhelmy. 2010. The distribution and speciation of dissolved trace metals in a shallow subterranean estuary. Marine Chemistry 121(1-4):145–156, https://doi.org/10.1016/j.marchem.2010.04.003.
Berelson, W.M., W.Z. Haskell, M. Prokopenko, A.N. Knapp, D.E. Hammond, N. Rollins, and D.G. Capone. 2015. Biogenic particle flux and benthic remineralization in the Eastern Tropical South Pacific. Deep Sea Research Part I 99:23–34, https://doi.org/10.1016/j.dsr.2014.12.006.
Berman-Frank, I., J.T. Cullen, Y. Shaked, R.M. Sherrell, and P.G. Falkowski. 2001. Iron availability, cellular iron quotas, and nitrogen fixation in Trichodesmium. Limnology and Oceanography 46(6):1,249–1,260, https://doi.org/10.4319/lo.2001.46.6.1249.
Bianchi, D., A.R. Babbin, and E.D. Galbraith. 2014. Enhancement of anammox by the excretion of diel vertical migrators. Proceedings of the National Academy of Sciences of the United States of America 111(44):15,653–15,658, https://doi.org/10.1073/pnas.1410790111.
Bock, E., H.-P. Koops, and H. Harms. 1989. Nitrifying bacteria. Pp. 81–96 in Autotrophic Bacteria. H.G. Schelgel and B. Bowien, eds, Springer-Verlag, Berlin.
Bonnet, S., H. Berthelot, K. Turk-Kubo, S. Fawcett, E. Rahav, S. L’Helguen, and I. Berman-Frank. 2016. Dynamics of N2 fixation and fate of diazotroph-derived nitrogen during the VAHINE mesocosm experiment. Biogeosciences 13:2,653–2,673, https://doi.org/10.5194/bg-13-2653-2016.
Bonnet, S., M. Caffin, H. Berthelot, and T. Moutin. 2017. Hot spot of N2 fixation in the western tropical South Pacific pleads for a spatial decoupling between N2 fixation and denitrification. Proceedings of the National Academy of Sciences of the United States of America 114(14):E2800–E2801, https://doi.org/10.1073/pnas.1619514114.
Bonnet, S., C. Guieu, V. Taillandier, C. Boulart, P. Bouruet-Aubertot, F. Gazeau, C. Scalabrin, M. Bressac, A.N. Knapp, Y. Cuypers, and others. 2023. Natural iron fertilization by shallow hydrothermal sources fuels diazotroph blooms in the ocean. Science 380(6647):812–817, https://doi.org/10.1126/science.abq4654.
Boshers, D.S., J. Granger, C.R. Tobias, J.K. Böhlke, and R.L. Smith. 2019. Constraining the oxygen isotopic composition of nitrate produced by nitrification. Environmental Science & Technology 53(3):1,206–1,216, https://doi.org/10.1021/acs.est.8b03386.
Bourbonnais, A., M.F. Lehmann, J.J. Waniek, and D.E. Schulz-Bull. 2009. Nitrate isotope anomalies reflect N2 fixation in the Azores Front region (subtropical NE Atlantic). Journal of Geophysical Research 114(C3), https://doi.org/10.1029/2007JC004617.
Bourbonnais, A., M.A. Altabet, C.N. Charoenpong, J. Larkum, H. Hu, H.W. Bange, and L. Stramma. 2015. N-loss isotope effects in the Peru oxygen minimum zone studied using a mesoscale eddy as a natural tracer experiment. Global Biogeochemical Cycles 29(6):793–811, https://doi.org/10.1002/2014GB005001.
Boyd, P.W., and M.J. Ellwood. 2010. The biogeochemical cycle of iron in the ocean. Nature Geoscience 3(10):675–682, https://doi.org/10.1038/ngeo964.
Brandes, J.A., and A.H. Devol. 1997. Isotopic fractionation of oxygen and nitrogen in coastal marine sediments. Geochimica et Cosmochimica Acta 61(9):1,793–1,801, https://doi.org/10.1016/S0016-7037(97)00041-0.
Brandes, J.A., A.H. Devol, T. Yoshinari, D.A. Jayakumar, and S.W.A. Naqvi. 1998. Isotopic composition of nitrate in the central Arabian Sea and eastern tropical North Pacific: A tracer for mixing and nitrogen cycles. Limnology and Oceanography 43(7):1,680–1,689, https://doi.org/10.4319/lo.1998.43.7.1680.
Brandes, J.A., and A.H. Devol. 2002. A global marine fixed nitrogen isotopic budget: Implications for Holocene nitrogen cycling. Global Biogeochemical Cycles 16(4):67-1–67-14, https://doi.org/10.1029/2001gb001856.
Bronk, D.A., and B.B. Ward. 1999. Gross and net nitrogen uptake and DON release in the euphotic zone of Monterey Bay, California. Limnology and Oceanography 44:573–585, https://doi.org/10.4319/lo.1999.44.3.0573.
Bronk, D.A., and B.B. Ward. 2000. Magnitude of dissolved organic nitrogen release relative to gross nitrogen uptake in marine systems. Limnology and Oceanography 45(8):1,879–1,883, https://doi.org/10.4319/lo.2000.45.8.1879.
Brown, Z.W., K.L. Casciotti, R.S. Pickart, J.H. Swift, and K.R. Arrigo. 2015. Aspects of the marine nitrogen cycle of the Chukchi Sea shelf and Canada Basin. Deep Sea Research Part II 118:73–87, https://doi.org/10.1016/j.dsr2.2015.02.009.
Bryant-Mason, A., Y.J. Xu, and M. Altabet. 2013. Isotopic signature of nitrate in river waters of the lower Mississippi and its distributary, the Atchafalaya. Hydrological Processes 27(19):2,840–2,850, https://doi.org/10.1002/hyp.9420.
Buchanan, P.J., X. Sun, J.L. Weissman, and E. Zakem. 2023. Oxygen intrusions sustain aerobic nitrite oxidation in anoxic marine zones. bioRxiv, https://doi.org/10.1101/2023.02.22.529547.
Buchwald, C., A.E. Santoro, M.R. McIlvin, and K.L. Casciotti. 2012. Oxygen isotopic composition of nitrate and nitrite produced by nitrifying cocultures and natural marine assemblages. Limnology and Oceanography 57(5):1,361–1,375, https://doi.org/10.4319/lo.2012.57.5.1361.
Capone, D.G., M.D. Ferrier, and E.J. Carpenter. 1994. Amino-acid cycling in colonies of the planktonic marine cyanobacterium Trichodesmium thiebautii. Applied and Environmental Microbiology 60(11):3,989–3,995, https://doi.org/10.1128/aem.60.11.3989-3995.1994.
Capone, D.G., M. Subramaniam, J.P. Montoya, M. Voss, C. Humborg, A.M. Johansen, R.L. Siefert, and E.J. Carpenter. 1998. An extensive bloom of N2-fixing cyanobacterium Trichodesmium erythraeum in the central Arabian Sea. Marine Ecology-Progress Series 172:237–281, https://doi.org/10.7916/D8416X1H.
Carpenter, E.J., H.R. Harvey, B. Fry, and D.G. Capone. 1997. Biogeochemical tracers of the marine cyanobacterium Trichodesmium. Deep Sea Research Part I 44(1):27–38, https://doi.org/10.1016/S0967-0637(96)00091-X.
Casciotti, K.L., D.M. Sigman, M.G. Hastings, J.K. Böhlke, and A. Hilkert. 2002. Measurement of the oxygen isotopic composition of nitrate in seawater and freshwater using the denitrifier method. Analytical Chemistry 74(19):4,905–4,912, https://doi.org/10.1021/ac020113w.
Casciotti, K.L., T.W. Trull, D.M. Glover, and D. Davies. 2008. Constraints on nitrogen cycling in the subtropical North Pacific Station ALOHA from isotopic measurements of nitrate and particulate nitrogen. Deep Sea Research II 55:1,661–1,672, https://doi.org/10.1016/j.dsr2.2008.04.017.
Casciotti, K.L. 2009. Inverse kinetic isotope fractionation during bacterial nitrite oxidation. Geochimica et Cosmochimica Acta 73(7):2,061–2,076, https://doi.org/10.1016/j.gca.2008.12.022.
Casciotti, K.L., and C. Buchwald. 2012. Insights on the marine microbial nitrogen cycle from isotopic approaches to nitrification. Frontiers in Microbiology 3:356, https://doi.org/10.3389/fmicb.2012.00356.
Casciotti, K.L., C. Buchwald, and M. McIlvin. 2013. Implications of nitrate and nitrite isotopic measurements for the mechanisms of nitrogen cycling in the Peru oxygen deficient zone. Deep Sea Research Part I 80:78–93, https://doi.org/10.1016/j.dsr.2013.05.017.
Casciotti, K.L. 2016a. Nitrite isotopes as tracers of marine N cycle processes. Philosophical Transactions of the Royal Society A 374(2081), https://doi.org/10.1098/rsta.2015.0295.
Casciotti, K.L. 2016b. Nitrogen and oxygen isotopic studies of the marine nitrogen cycle. Annual Review of Marine Science 8:379–407, https://doi.org/10.1146/annurev-marine-010213-135052.
Chang, B.X., A.H. Devol, and S.R. Emerson. 2010. Denitrification and the nitrogen gas excess in the eastern tropical South Pacific oxygen deficient zone. Deep Sea Research Part I 57(9):1,092–1,101, https://doi.org/10.1016/j.dsr.2010.05.009.
Chen, X., H.K. Kwon, D. Joung, C. Baek, T.G. Park, M. Son, and G. Kim. 2022. Role of terrestrial versus marine sources of humic dissolved organic matter on the behaviors of trace elements in seawater. Geochimica et Cosmochimica Acta 333:333–346, https://doi.org/10.1016/j.gca.2022.07.025.
Chen, X.-G., D. Rusiecka, M. Gledhill, A. Milne, A.L. Annett, A.J. Birchill, M.C. Lohan, S. Ussher, E.M.S. Woodward, and E.P. Achterberg. 2023. Ocean circulation and biological processes drive seasonal variations of dissolved Al, Cd, Ni, Cu, and Zn on the Northeast Atlantic continental margin. Marine Chemistry 252:104246, https://doi.org/10.1016/j.marchem.2023.104246.
Chowdhury, S., E. Raes, C. Hörstmann, A. Ahmed, C. Ridame, N. Metzl, P.S. Bhavya, T. Sato, T. Shiozaki, S. Bonnet, and others. 2023. Diazotrophy in the Indian Ocean: Current understanding and future perspectives. Limnology and Oceanography Letters 8(5):707–722, https://doi.org/10.1002/lol2.10343.
Cline, J.D., and F.A. Richards. 1972. Oxygen deficient conditions and nitrate reduction in the Eastern Tropical North Pacific Ocean. Limnology and Oceanography 17(6):885–900, https://doi.org/10.4319/lo.1972.17.6.0885.
Cline, J.D., and I.R. Kaplan. 1975. Isotopic fractionation of dissolved nitrate during denitrification in the eastern tropical North Pacific Ocean. Marine Chemistry 3:271–299, https://doi.org/10.1016/0304-4203(75)90009-2.
Codispoti, L.A. 2007. An oceanic fixed nitrogen sink exceeding 400 Tg N a–1 vs the concept of homeostasis in the fixed-nitrogen inventory. Biogeosciences 4(2):233–253, https://doi.org/10.5194/bg-4-233-2007.
Conway, T.M., and S.G. John. 2014. Quantification of dissolved iron sources to the North Atlantic Ocean. Nature 511(7508):212–215, https://doi.org/10.1038/nature13482.
Dekaezemacker, J., S. Bonnet, O. Grosso, T. Moutin, M. Bressac, and D.G. Capone. 2013. Evidence of active dinitrogen fixation in surface waters of the eastern tropical South Pacific during El Niño and La Niña events and evaluation of its potential nutrient controls. Global Biogeochemical Cycles 27(3):768–779, https://doi.org/10.1002/gbc.20063.
Deman, F., D. Fonseca-Batista, A. Roukaerts, M.I. García-Ibáñez, E. Le Roy, E.P.D.N. Thilakarathne, M. Elskens, F. Dehairs, and F. Fripiat. 2021. Nitrate supply routes and impact of internal cycling in the North Atlantic Ocean inferred from nitrate isotopic composition. Global Biogeochemical Cycles 35(4):e2020GB006887, https://doi.org/10.1029/2020GB006887.
Deutsch, C., N. Gruber, R.M. Key, J.L. Sarmiento, and A. Ganaschaud. 2001. Denitrification and N2 fixation in the Pacific Ocean. Global Biogeochemical Cycles 15(2):483–506, https://doi.org/10.1029/2000GB001291.
Deutsch, C., D.M. Sigman, R.C. Thunell, A.N. Meckler, and G.H. Haug. 2004. Isotopic constraints on glacial/interglacial changes in the oceanic nitrogen budget. Global Biogeochemical Cycles 18(4), https://doi.org/10.1029/2003GB002189.
Deutsch, C., J.L. Sarmiento, D.M. Sigman, N. Gruber, and J.P. Dunne. 2007. Spatial coupling of nitrogen inputs and losses in the ocean. Nature 445:163–167, https://doi.org/10.1038/nature05392.
DeVries, T., C. Deutsch, F. Primeau, B. Chang, and A. Devol. 2012. Global rates of water-column denitrification derived from nitrogen gas measurements. Nature Geoscience 5(8):547–550, https://doi.org/10.1038/ngeo1515.
DeVries, T., C. Deutsch, P.A. Rafter, and F. Primeau. 2013. Marine denitrification rates determined from a global 3-D inverse model. Biogeosciences 10(4):2,481–2,496, https://doi.org/10.5194/bg-10-2481-2013.
DiFiore, P.J., D.M. Sigman, T.W. Trull, M.J. Lourey, K.L. Karsh, G. Cane, and R. Ho. 2006. Nitrogen isotope constraints on subantarctic biogeochemistry. Journal of Geophysical Research: Oceans 111(C8), https://doi.org/10.1029/2005jc003216.
Duce, R.A., P.S. Liss, J.T. Merrill, E.L. Atlas, P. Buat-Menard, B.B. Hicks, J.M. Miller, J.M. Prospero, R. Arimoto, T.M. Church, and others. 1991. The atmospheric input of trace species to the world ocean. Global Biogeochemical Cycles 5(3):193–259, https://doi.org/10.1029/91GB01778.
Dugdale, R.C., and J.J. Goering. 1967. Uptake of new and regenerated forms of nitrogen in marine production. Limnology and Oceanography 12:196–206, https://doi.org/10.4319/lo.1967.12.2.0196.
Duhamel, S., J.M. Diaz, J.C. Adams, K. Djaoudi, V. Steck, and E.M. Waggoner. 2021. Phosphorus as an integral component of global marine biogeochemistry. Nature Geoscience 14(6):359–368, https://doi.org/10.1038/s41561-021-00755-8.
Dupont, C.L., K. Barbeau, and B. Palenik. 2008. Ni uptake and limitation in marine Synechococcus strains. Applied and Environmental Microbiology 74(1):23–31, https://doi.org/10.1128/AEM.01007-07.
Dyhrman, S.T., and K.C. Ruttenberg. 2006. Presence and regulation of alkaline phosphatase activity in eukaryotic phytoplankton from the coastal ocean: Implications for dissolved organic phosphorus remineralization. Limnology and Oceanography 51(3):1,381–1,390, https://doi.org/10.4319/lo.2006.51.3.1381.
Eppley, R.W., and B.J. Peterson. 1979. Particulate organic matter flux and planktonic new production in the deep ocean. Nature 282:677–680, https://doi.org/10.1038/282677a0.
Fawcett, S.E., B.B. Ward, M.W. Lomas, and D.M. Sigman. 2015. Vertical decoupling of nitrate assimilation and nitrification in the Sargasso Sea. Deep Sea Research Part I 103:64–72, https://doi.org/10.1016/j.dsr.2015.05.004.
Fawcett, S.E., K.S. Johnson, S.C. Riser, N. Van Oostende, and D.M. Sigman. 2018. Low-nutrient organic matter in the Sargasso Sea thermocline: A hypothesis for its role, identity, and carbon cycle implications. Marine Chemistry 207:108–123, https://doi.org/10.1016/j.marchem.2018.10.008.
Ferguson, S.J., D.J. Richardson, and R.J.M. van Spanning. 2007. Biochemistry and molecular biology of nitrification. Pp. 209–222 in Biology of the Nitrogen Cycle. H. Bothe, S.J. Ferguson, and W.E. Newton, eds, Elsevier, Amsterdam, https://doi.org/10.1016/B978-044452857-5.50015-1.
Fernandez, C., L. Farias, and O. Ulloa. 2011. Nitrogen fixation in denitrified marine waters. PLoS ONE 6:e20539, https://doi.org/10.1371/journal.pone.0020539.
Fitzsimmons, J.N., S.G. John, C.M. Marsay, C.L. Hoffman, S.L. Nicholas, B.M. Toner, C.R. German, and R.M. Sherrell. 2017. Iron persistence in a distal hydrothermal plume supported by dissolved–particulate exchange. Nature Geoscience 10(3):195–201, https://doi.org/10.1038/ngeo2900.
Fitzsimmons, J.N., and T.M. Conway. 2023. Novel insights into marine iron biogeochemistry from iron isotopes. Annual Review of Marine Science 15(1):383–406, https://doi.org/10.1146/annurev-marine-032822-103431.
Flynn, R.F., J. Granger, J.A. Veitch, S. Siedlecki, J.M. Burger, K. Pillay, and S.E. Fawcett. 2020. On-shelf nutrient trapping enhances the fertility of the southern Benguela upwelling system. Journal of Geophysical Research: Oceans 125(6):e2019JC015948, https://doi.org/10.1029/2019JC015948.
Forrer, H.J., S. Bonnet, R.K. Thomas, O. Grosso, C. Guieu, and A.N. Knapp. 2023. Quantifying N2 fixation and its contribution to export production near the Tonga-Kermadec Arc using nitrogen isotope budgets. Frontiers in Marine Science 10:1249115, https://doi.org/10.3389/fmars.2023.1249115.
Fripiat, F., M. Declercq, C.J. Sapart, L.G. Anderson, V. Bruechert, F. Deman, D. Fonseca-Batista, C. Humborg, A. Roukaerts, I.P. Semiletov, and F. Dehairs. 2018. Influence of the bordering shelves on nutrient distribution in the Arctic halocline inferred from water column nitrate isotopes. Limnology and Oceanography 63(5):2,154–2,170, https://doi.org/10.1002/lno.10930.
Fripiat, F., A. Martínez-García, S.E. Fawcett, P.C. Kemeny, A.S. Studer, S.M. Smart, F. Rubach, S. Oleynik, D.M. Sigman, and G.H. Haug. 2019. The isotope effect of nitrate assimilation in the Antarctic Zone: Improved estimates and paleoceanographic implications. Geochimica et Cosmochimica Acta 247:261–279, https://doi.org/10.1016/j.gca.2018.12.003.
Fripiat, F., A. Martínez-García, D. Marconi, S.E. Fawcett, S.H. Kopf, V.H. Luu, P.A. Rafter, R. Zhang, D.M. Sigman, and G.H. Haug. 2021a. Nitrogen isotopic constraints on nutrient transport to the upper ocean. Nature Geoscience 14(11):855–861, https://doi.org/10.1038/s41561-021-00836-8.
Fripiat, F., D. Marconi, P.A. Rafter, D.M. Sigman, M.A. Altabet, A. Bourbonnais, J. Brandes, K.K.L. Casciotti, F. Deman, F. Dehairs, and others. 2021b. Compilation of nitrate δ15N in the Ocean, https://doi.org/10.1594/PANGAEA.936484.
Fripiat, F., D.M. Sigman, A. Martínez-García, D. Marconi, X.E. Ai, A. Auderset, S.E. Fawcett, S. Moretti, A.S. Studer, and G.H. Haug. 2023. The impact of incomplete nutrient consumption in the Southern Ocean on global mean ocean nitrate δ15N. Global Biogeochemical Cycles 37(2):e2022GB007442, https://doi.org/10.1029/2022GB007442.
Fussel, J., P. Lam, G. Lavik, M.M. Jensen, M. Holtappels, M. Gunter, and M.M.M. Kuypers. 2012. Nitrite oxidation in the Namibian oxygen minimum zone. The ISME Journal 6:1,200–1,209, https://doi.org/10.1038/ismej.2011.178.
Gaye, B., B. Nagel, K. Dähnke, T. Rixen, and K.C. Emeis. 2013. Evidence of parallel denitrification and nitrite oxidation in the ODZ of the Arabian Sea from paired stable isotopes of nitrate and nitrite. Global Biogeochemical Cycles 27(4):1,059–1,071, https://doi.org/10.1002/2011GB004115.
GEOTRACES Intermediate Data Product Group. 2023. The GEOTRACES Intermediate Data Product 2021 version 2 (IDP2021v2), https://doi.org/10.5285/ff46f034-f47c-05f9-e053-6c86abc0dc7e.
Glibert, P.M., and D.A. Bronk. 1994. Release of dissolved organic nitrogen by marine diazotrophic cyanobacteria, Trichodesmium spp. Applied and Environmental Microbiology 60(11):3,996–4,000, https://doi.org/10.1128/aem.60.11.3996-4000.1994.
Grand, M.M., C.I. Measures, M. Hatta, P.L. Morton, P. Barrett, A. Milne, J.A. Resing, and W.M. Landing. 2015. The impact of circulation and dust deposition in controlling the distributions of dissolved Fe and Al in the south Indian subtropical gyre. Marine Chemistry 176:110–125, https://doi.org/10.1016/j.marchem.2015.08.002.
Granger, J., D.M. Sigman, J.A. Needoba, and P.J. Harrison. 2004. Coupled nitrogen and oxygen isotope fractionation of nitrate during assimilation by cultures of marine phytoplankton. Limnology and Oceanography 49(5):1,763–1,773, https://doi.org/10.4319/lo.2004.49.5.1763.
Granger, J., D.M. Sigman, M.F. Lehmann, and P.D. Tortell. 2008. Nitrogen and oxygen isotope fractionation during dissimilatory nitrate reduction by denitrifying bacteria. Limnology and Oceanography 53(6):2,533–2,545, https://doi.org/10.4319/lo.2008.53.6.2533.
Granger, J., D.M. Sigman, M.M. Rohde, M.T. Maldonado, and P.D. Tortell. 2010. N and O isotope effects during nitrate assimilation by unicellular prokaryotic and eukaryotic plankton cultures. Geochimica et Cosmochimica Acta 74:1,030–1,040, https://doi.org/10.1016/j.gca.2009.10.044.
Granger, J., M.G. Prokopenko, D.M. Sigman, C.W. Mordy, Z.M. Morse, L.V. Morales, R.N. Sambrotto, and B. Plessen. 2011. Coupled nitrification-denitrification in sediment of the eastern Bering Sea shelf leads to 15N enrichment of fixed N in shelf waters. Journal of Geophysical Research 116(C11), https://doi.org/10.1029/2010JC006751.
Granger, J., M.G. Prokopenko, C.W. Mordy, and D.M. Sigman. 2013. The proportion of remineralized nitrate on the ice-covered eastern Bering Sea shelf evidenced from the oxygen isotope ratio of nitrate. Global Biogeochemical Cycles 27(3):962–971, https://doi.org/10.1002/gbc.20075.
Gruber, N., and J.L. Sarmiento. 1997. Global patterns of marine nitrogen fixation and denitrification. Global Biogeochemical Cycles 11:235–266, https://doi.org/10.1029/97GB00077.
Hansell, D.A., and C.A. Carlson. 1998. Net community production of dissolved organic carbon. Global Biogeochemical Cycles 12(3):443–453, https://doi.org/10.1029/98GB01928.
Hansell, D.A., C.A. Carlson, R.M.W. Amon, X.A. Alvarez-Salgado, Y. Yamashita, C. Romera-Castillo, and M.B. Bif. 2021. Compilation of dissolved organic matter (DOM) data obtained from global ocean observations from 1994 to 2021. Version 2 (NCEI Accession 0227166), NOAA National Centers for Environmental Information. Data set, https://doi.org/10.25921/s4f4-ye35.
Hatta, M., C.I. Measures, J. Wu, S. Roshan, J.N. Fitzsimmons, P. Sedwick, and P. Morton. 2015. An overview of dissolved Fe and Mn distributions during the 2010–2011 US GEOTRACES north Atlantic cruises: GEOTRACES GA03. Deep Sea Research Part II 116:117–129, https://doi.org/10.1016/j.dsr2.2014.07.005.
Held, N.A., E.A. Webb, M.M. McIlvin, D.A. Hutchins, N.R. Cohen, D.M. Moran, K. Kunde, M.C. Lohan, C. Mahaffey, E.M.S. Woodward, and M.A. Saito. 2020. Co-occurrence of Fe and P stress in natural populations of the marine diazotroph Trichodesmium. Biogeosciences 17(9):2,537–2,551, https://doi.org/10.5194/bg-17-2537-2020.
Holl, C.M., T.A. Villareal, C.D. Payne, T.D. Clayton, C. Hart, and J.P. Montoya. 2007. Trichodesmium in the western Gulf of Mexico: 15N2-fixation and natural abundance stable isotopic evidence. Limnology and Oceanography 52(5):2,249–2,259, https://doi.org/10.4319/lo.2007.52.5.2249.
Homoky, W.B., T.M. Conway, S.G. John, D. König, F. Deng, A. Tagliabue, and R.A. Mills. 2021. Iron colloids dominate sedimentary supply to the ocean interior. Proceedings of the National Academy of Sciences of the United States of America 118(13):e2016078118, https://doi.org/10.1073/pnas.2016078118.
Horii, S., K. Takahashi, T. Shiozaki, S. Takeda, M. Sato, T. Yamaguchi, S. Takino, F. Hashihama, Y. Kondo, T. Takemura, and K. Furuya. 2023. East-west variabilities of N2 fixation activity in the subtropical North Pacific Ocean in summer: Potential field evidence of the phosphorus and iron co-limitation in the western area. Journal of Geophysical Research: Oceans 128(6):e2022JC019249, https://doi.org/10.1029/2022JC019249.
Howe, S., C. Miranda, C.T. Hayes, R.T. Letscher, and A.N. Knapp. 2020. The dual isotopic composition of nitrate in the Gulf of Mexico and Florida Straits. Journal of Geophysical Research: Oceans 125(9):e2020JC016047, https://doi.org/10.1029/2020JC016047.
Hutchings, L., C.D. van der Lingen, L.J. Shannon, R.J.M. Crawford, H.M.S. Verheye, C.H. Bartholomae, A.K. van der Plas, D. Louw, A. Kreiner, M. Ostrowski, and others. 2009. The Benguela Current: An ecosystem of four components. Progress in Oceanography 83(1):15–32, https://doi.org/10.1016/j.pocean.2009.07.046.
Izett, J.G., and K. Fennel. 2018. Estimating the cross-shelf export of riverine materials: Part 2. Estimates of global freshwater and nutrient export. Global Biogeochemical Cycles 32(2):176–186, https://doi.org/10.1002/2017GB005668.
Jayakumar, A., B.X. Chang, B. Widner, P. Bernhardt, M.R. Mulholland, and B.B. Ward. 2017. Biological nitrogen fixation in the oxygen-minimum region of the eastern tropical North Pacific Ocean. The ISME Journal 11(10):2,356–2,367, https://doi.org/10.1038/ismej.2017.97.
Jenkins, W.J., M. Hatta, J.N. Fitzsimmons, R. Schlitzer, N.T. Lanning, A. Shiller, N.R. Buckley, C.R. German, D.E. Lott, G. Weiss, and others. 2020. An intermediate-depth source of hydrothermal 3He and dissolved iron in the North Pacific. Earth and Planetary Science Letters 539:116223, https://doi.org/10.1016/j.epsl.2020.116223.
Jickells, T.D., Z.S. An, K.K. Andersen, A.R. Baker, G. Bergametti, N. Brooks, J.J. Cao, P.W. Boyd, R.A. Duce, K.A. Hunter, and others. 2005. Global iron connections between desert dust, ocean biogeochemistry, and climate. Science 308(5718):67–71, https://doi.org/10.1126/science.1105959.
Jickells, T.D., E. Buitenhuis, K. Altieri, A.R. Baker, D. Capone, R.A. Duce, F. Dentener, K. Fennel, M. Kanakidou, J. LaRoche, and others. 2017. A reevaluation of the magnitude and impacts of anthropogenic atmospheric nitrogen inputs on the ocean. Global Biogeochemical Cycles 31(2):289–305, https://doi.org/10.1002/2016GB005586.
Karl, D., R. Letelier, L. Tupas, J. Dore, J. Christian, and D. Hebel. 1997. The role of nitrogen fixation in biogeochemical cycling in the subtropical North Pacific Ocean. Nature 388(6642):533–538, https://doi.org/10.1038/41474.
Karsh, K.L., T.W. Trull, A.J. Lourey, and D.M. Sigman. 2003. Relationship of nitrogen isotope fractionation to phytoplankton size and iron availability during the Southern Ocean Iron RElease Experiment (SOIREE). Limnology and Oceanography 48(3):1,058–1,068, https://doi.org/10.4319/lo.2003.48.3.1058.
Karsh, K., J. Granger, K. Kritee, and D.M. Sigman. 2012. Eukaryotic assimilatory nitrate reductase fractionates N and O isotopes with a ratio near unity. Environmental Science & Technology 46:5,727–5,735, https://doi.org/10.1021/es204593q.
Kartal, B., and J.T. Keltjens. 2016. Anammox biochemistry: A tale of heme c proteins. Trends in Biochemical Sciences 41(12):998–1,011, https://doi.org/10.1016/j.tibs.2016.08.015.
Knapp, A.N., D.M. Sigman, and F. Lipschultz. 2005. N isotopic composition of dissolved organic nitrogen and nitrate at the Bermuda Atlantic Time-series Study site. Global Biogeochemical Cycles 19(1), https://doi.org/10.1029/2004GB002320.
Knapp, A.N., P.J. DiFiore, C. Deutsch, D.M. Sigman, and F. Lipschultz. 2008. Nitrate isotopic composition between Bermuda and Puerto Rico: Implications for N2 fixation in the Atlantic Ocean. Global Biogeochemical Cycles 22(3), https://doi.org/10.1029/2007gb003107.
Knapp, A.N., D.M. Sigman, F. Lipschultz, A.B. Kustka, and D.G. Capone. 2011. Interbasin isotopic correspondence between upper-ocean bulk DON and subsurface nitrate and its implications for marine nitrogen cycling. Global Biogeochemical Cycles 25(4), https://doi.org/10.1029/2010GB003878.
Knapp, A., J. Dekaezemacker, S. Bonnet, J. Sohm, and D. Capone. 2012. Sensitivity of Trichodesmium erythraeum and Crocosphaera watsonii abundance and N2 fixation rates to varying NO3− and PO43− concentrations in batch cultures. Aquatic Microbial Ecology 66(3):223–236, https://doi.org/10.3354/ame01577.
Knapp, A.N., K.L. Casciotti, W.M. Berelson, M.G. Prokopenko, and D.G. Capone. 2016a. Low rates of nitrogen fixation in eastern tropical South Pacific surface waters. Proceedings of the National Academy of Sciences of the United States of America 113(16):4,398–4,403, https://doi.org/10.1073/pnas.1515641113.
Knapp, A.N., S.E. Fawcett, A. Martínez-Garcia, N. Leblond, T. Moutin, and S. Bonnet. 2016b. Nitrogen isotopic evidence for a shift from nitrate- to diazotroph-fueled export production in the VAHINE mesocosm experiments. Biogeosciences 13(16):4,645–4,657, https://doi.org/10.5194/bg-13-4645-2016.
Knapp, A.N., K.L. Casciotti, and M.G. Prokopenko. 2018. Dissolved organic nitrogen production and consumption in eastern tropical South Pacific surface waters. Global Biogeochemical Cycles 32(5):769–783, https://doi.org/10.1029/2017GB005875.
Knapp, A.N., R.K. Thomas, M.R. Stukel, T.B. Kelly, M.R. Landry, K.E. Selph, E. Malca, T. Gerard, and J. Lamkin. 2022. Constraining the sources of nitrogen fueling export production in the Gulf of Mexico using nitrogen isotope budgets. Journal of Plankton Research 44(5):692–710, https://doi.org/10.1093/plankt/fbab049.
Kritee, K., D.M. Sigman, J. Granger, B.B. Ward, A. Jayakumar, and C. Deutsch. 2012. Reduced isotope fractionation by denitrification under conditions relevant to the ocean. Geochimica et Cosmochimica Acta 92:243–259, https://doi.org/10.1016/j.gca.2012.05.020.
Kuypers, M.M.M., G. Lavik, D. Woebken, M. Schmid, B.M. Fuchs, R. Amann, B.B. Jorgensen, and M.S.M. Jetten. 2005. Massive nitrogen loss from the Benguela upwelling system through anaerobic ammonium oxidation. Proceedings of the National Academy of Sciences of the United States of America 102(18):6,478–6,483, https://doi.org/10.1073/pnas.0502088102.
Lam, P., G. Lavik, M.M. Jensen, J. van de Vossenberg, M. Schmid, D. Woebken, G. Dimitri, R. Amann, M.S.M. Jetten, and M.M.M. Kuypers. 2009. Revising the nitrogen cycle in the Peruvian oxygen minimum zone. Proceedings of the National Academy of Sciences of the United States of America 106(12):4,752–4,757, https://doi.org/10.1073/pnas.0812444106.
Landolfi, A., W. Koeve, H. Dietze, P. Kähler, and A. Oschlies. 2015. A new perspective on environmental controls of marine nitrogen fixation. Geophysical Research Letters 42(11):4,482–4,489, https://doi.org/10.1002/2015GL063756.
Landolfi, A., P. Kähler, W. Koeve, and A. Oschlies. 2018. Global marine N2 fixation estimates: From observations to models. Frontiers in Microbiology 9:2112, https://doi.org/10.3389/fmicb.2018.02112.
Lehmann, M.F., D.M. Sigman, D.C. McCorkle, J. Granger, S. Hoffmann, G. Cane, and B.G. Brunelle. 2007. The distribution of nitrate 15N/14N in marine sediments and the impact of benthic nitrogen loss on the isotopic composition of oceanic nitrate. Geochimica et Cosmochimica Acta 71(22):5,384–5,404, https://doi.org/10.1016/j.gca.2007.07.025.
Lehmann, N., J. Granger, M. Kienast, K.S. Brown, P.A. Rafter, G. Martínez-Méndez, and M. Mohtadi. 2018. Isotopic evidence for the evolution of subsurface nitrate in the western equatorial Pacific. Journal of Geophysical Research: Oceans 123(3):1,684–1,707, https://doi.org/10.1002/2017JC013527.
Lehmann, N., M. Kienast, J. Granger, A. Bourbonnais, M.A. Altabet, and J. Tremblay. 2019. Remote western Arctic nutrients fuel remineralization in deep Baffin Bay. Global Biogeochemical Cycles 33(6):649–667, https://doi.org/10.1029/2018GB006134.
Letscher, R.T., D.A. Hansell, C.A. Carlson, R. Lumpkin, and A.N. Knapp. 2013. Dissolved organic nitrogen in the global surface ocean: Distribution and fate. Global Biogeochemical Cycles 27(1):141–153, https://doi.org/10.1029/2012GB004449.
Letscher, R.T., F. Primeau, and J.K. Moore. 2016. Nutrient budgets in the subtropical ocean gyres dominated by lateral transport. Nature Geoscience 9(11):815–821, https://doi.org/10.1038/ngeo2812.
Letscher, R.T., W.-L. Wang, Z. Liang, and A.N. Knapp. 2022. Regionally variable contribution of dissolved organic phosphorus to marine annual net community production. Global Biogeochemical Cycles 36(12):e2022GB007354, https://doi.org/10.1029/2022GB007354.
Liang, Z., R.T. Letscher, and A.N. Knapp. 2022a. Dissolved organic phosphorus concentrations in the surface ocean controlled by both phosphate and iron stress. Nature Geoscience 15(8):651–657, https://doi.org/10.1038/s41561-022-00988-1.
Liang, Z., K. McCabe, S.E. Fawcett, H.J. Forrer, F. Hashihama, C. Jeandel, D. Marconi, H. Planquette, M.A. Saito, J.A. Sohm, and others. 2022b. A global ocean dissolved organic phosphorus concentration database (DOPv2021). Scientific Data 9(1):772, https://doi.org/10.1038/s41597-022-01873-7.
Liang, Z., R.T. Letscher, and A.N. Knapp. 2023. Global patterns of surface ocean dissolved organic matter stoichiometry. Global Biogeochemical Cycles 37:e2023GB007788, https://doi.org/10.1029/2023GB007788.
Lourey, M.J., T.W. Trull, and D.M. Sigman. 2003. Sensitivity of δ15N of nitrate, surface suspended and deep sinking particulate nitrogen to seasonal nitrate depletion in the Southern Ocean. Global Biogeochemical Cycles 17(3), https://doi.org/10.1029/2002GB001973.
Luo, Y.-W., S.C. Doney, L.A. Anderson, M. Benavides, I. Berman-Frank, A. Bode, S. Bonnet, K.H. Boström, D. Böttjer, D.G. Capone, and others. 2012. Database of diazotrophs in global ocean: Abundance, biomass and nitrogen fixation rates. Earth System Science Data 4(1):47–73, https://doi.org/10.5194/essd-4-47-2012.
Mahowald, N.M., A.R. Baker, G. Bergametti, N. Brooks, R.A. Duce, T.D. Jickells, N. Kubilay, J.M. Prospero, and I. Tegen. 2005. Atmospheric global dust cycle and iron inputs to the ocean. Global Biogeochemical Cycles 19(4), https://doi.org/10.1029/2004GB002402.
Mahowald, N.M., S. Engelstaedter, C. Luo, A. Sealy, P. Artaxo, C. Benitez-Nelson, S. Bonnet, Y. Chen, P.Y. Chuang, D.D. Cohen, and others. 2009. Atmospheric iron deposition: Global distribution, variability, and human perturbations. Annual Review of Marine Science 1:245–278, https://doi.org/10.1146/annurev.marine.010908.163727.
Marconi, D., M. Alexandra Weigand, P.A. Rafter, M.R. McIlvin, M. Forbes, K.L. Casciotti, and D.M. Sigman. 2015. Nitrate isotope distributions on the US GEOTRACES North Atlantic cross-basin section: Signals of polar nitrate sources and low latitude nitrogen cycling. Marine Chemistry 177:143–156, https://doi.org/10.1016/j.marchem.2015.06.007.
Marconi, D., S. Kopf, P.A. Rafter, and D.M. Sigman. 2017a. Aerobic respiration along isopycnals leads to overestimation of the isotope effect of denitrification in the ocean water column. Geochimica et Cosmochimica Acta 197:417–432, https://doi.org/10.1016/j.gca.2016.10.012.
Marconi, D., D M. Sigman, K.L. Casciotti, E.C. Campbell, M.A. Weigand, S.E. Fawcett, A.N. Knapp, P.A. Rafter, B.B. Ward, and G.H. Haug. 2017b. Tropical dominance of N2 fixation in the North Atlantic Ocean. Global Biogeochemical Cycles 31(10), https://doi.org/10.1002/2016GB005613.
Marconi, D., M.A. Weigand, and D.M. Sigman. 2019. Nitrate isotopic gradients in the North Atlantic Ocean and the nitrogen isotopic composition of sinking organic matter. Deep Sea Research Part I 145:109–124, https://doi.org/10.1016/j.dsr.2019.01.010.
Mariotti, A., J.C. Germon, P. Hubert, P. Kaiser, R. Letolle, A. Tardieux, and P. Tardieux. 1981. Experimental determination of nitrogen kinetic isotope fractionation: Dome principles; Illustration for the denitrification and nitrification processes. Plant and Soil 62:413–430, https://doi.org/10.1007/BF02374138.
Marshall, T., J. Granger, K.L. Casciotti, K. Dähnke, K.C. Emeis, D. Marconi, M.R. McIlvin, A.E. Noble, M.A. Saito, D.M. Sigman, and S.E. Fawcett. 2022. The Angola Gyre is a hotspot of dinitrogen fixation in the South Atlantic Ocean. Communications Earth and Environment 3:151, https://doi.org/10.1038/s43247-022-00474-x.
Marshall, T.A., D.M. Sigman, L.M. Beal, A. Foreman, A. Martínez-García, S. Blain, E. Campbell, F. Fripiat, R. Granger, E. Harris, and others. 2023. The Agulhas Current transports signals of local and remote Indian Ocean nitrogen cycling. Journal of Geophysical Research: Oceans 128(3):e2022JC019413, https://doi.org/10.1029/2022JC019413.
Martin, J.H., M. Gordon, and S.E. Fitzwater. 1991. The case for iron. Limnology and Oceanography 36(8):1,793–1,802, https://doi.org/10.4319/lo.1991.36.8.1793.
Martin, T.S., F. Primeau, and K.L. Casciotti. 2019a. Assessing marine nitrogen cycle rates and process sensitivities with a global 3-D inverse model. Global Biogeochemical Cycles 33(8), https://doi.org/10.1029/2018GB006088.
Martin, T.S., F. Primeau, and K.L. Casciotti. 2019b. Modeling oceanic nitrate and nitrite concentrations and isotopes using a 3-D inverse N cycle model. Biogeosciences, https://doi.org/10.5194/bg-16-347-2019.
Martiny, A.C., C.T.A. Pham, F.W. Primeau, J.A. Vrugt, J.K. Moore, S.A. Levin, and M.W. Lomas. 2013. Strong latitudinal patterns in the elemental ratios of marine plankton and organic matter. Nature Geoscience 6(4):279–283, https://doi.org/10.1038/ngeo1757.
Matiatos, I., L.I. Wassenaar, L.R. Monteiro, J.J. Venkiteswaran, D.C. Gooddy, P. Boeckx, E. Sacchi, F.-J. Yue, G. Michalski, C. Alonso-Hernández, and others. 2021. Global patterns of nitrate isotope composition in rivers and adjacent aquifers reveal reactive nitrogen cascading. Communications Earth & Environment 2:52, https://doi.org/10.1038/s43247-021-00121-x.
Mellett, T., and K.N. Buck. 2020. Spatial and temporal variability of trace metals (Fe, Cu, Mn, Zn, Co, Ni, Cd, Pb), iron and copper speciation, and electroactive Fe-binding humic substances in surface waters of the eastern Gulf of Mexico. Marine Chemistry 227:103891, https://doi.org/10.1016/j.marchem.2020.103891.
Mills, M.M., C. Ridame, M. Davey, J. La Roche, and R.J. Geider. 2004. Iron and phosphorus co-limit nitrogen fixation in the eastern tropical North Atlantic. Nature 429(6989):292–294, https://doi.org/10.1038/nature02550.
Mills, M.M., and K.R. Arrigo. 2010. Magnitude of oceanic nitrogen fixation influenced by the nutrient uptake ratio of phytoplankton. Nature Geoscience 3(6):412–416, https://doi.org/10.1038/ngeo856.
Montoya, J.P., M. Voss, P. Kahler, and D.G. Capone. 1996. A simple, high-precision, high-sensitivity tracer assay for N(inf2) fixation. Applied and Environmental Microbiology 62(3):986–993, https://doi.org/10.1128/aem.62.3.986-993.1996.
Montoya, J.P., E. Carpenter, and D. Capone. 2002. Nitrogen fixation and nitrogen isotope abundance in zooplankton of the oligotrophic North Atlantic. Limnology and Oceanography 47:1,617–1,628, https://doi.org/10.4319/lo.2002.47.6.1617.
Moore, C.M., M.M. Mills, E.P. Achterberg, R.J. Geider, J. LaRoche, M.I. Lucas, E.L. McDonagh, X. Pan, A.J. Poulton, M.J.A. Rijkenberg, and others. 2009. Large-scale distribution of Atlantic nitrogen fixation controlled by iron availability. Nature Geoscience 2(12):867–871, https://doi.org/10.1038/ngeo667.
Morel, F.M.M., and N.M. Price. 2003. The biogeochemical cycles of trace metals in the oceans. Science 300(5621):944–947, https://doi.org/10.1126/science.1083545.
Morel, F.M.M., P.J. Lam, and M.A. Saito. 2020. Trace metal substitution in marine phytoplankton. Annual Review of Earth and Planetary Sciences 48(1):491–517, https://doi.org/10.1146/annurev-earth-053018-060108.
Noble, A.E., C.H. Lamborg, D.C. Ohnemus, P.J. Lam, T.J. Goepfert, C.I. Measures, C.H. Frame, K.L. Casciotti, G.R. DiTullio, J. Jennings, and M.A. Saito. 2012. Basin-scale inputs of cobalt, iron, and manganese from the Benguela-Angola front to the South Atlantic Ocean. Limnology and Oceanography 57(4):989–1,010, https://doi.org/10.4319/lo.2012.57.4.0989.
Orchard, E.D., J.W. Ammerman, M.W. Lomas, and S.T. Dyhrman. 2010. Dissolved inorganic and organic phosphorus uptake in Trichodesmium and the microbial community: The importance of phosphorus ester in the Sargasso Sea. Limnology and Oceanography 55(3):1,390–1,399, https://doi.org/10.4319/lo.2010.55.3.1390.
Palenik, B., and F.M.M. Morel. 1991. Amine oxidases of marine phytoplankton. Applied and Environmental Microbiology 57(8):2,440–2,443, https://doi.org/10.1128/aem.57.8.2440-2443.1991.
Peters, B., R. Horak, A. Devol, C. Fuchsman, M. Forbes, C.W. Mordy, and K.L. Casciotti. 2018a. Estimating fixed nitrogen loss and associated isotope effects using concentration and isotope measurements of NO3–, NO2–, and N2 from the eastern tropical South Pacific oxygen deficient zone. Deep Sea Research Part II 156:121–136, https://doi.org/10.1016/j.dsr2.2018.02.011.
Peters, B.D., P.J. Lam, and K.L. Casciotti. 2018b. Nitrogen and oxygen isotope measurements of nitrate along the US GEOTRACES Eastern Pacific Zonal Transect (GP16) yield insights into nitrate supply, remineralization, and water mass transport. Marine Chemistry 201:137–150, https://doi.org/10.1016/j.marchem.2017.09.009.
Rabalais, N.N., R.E. Turner, D. Justić, Q. Dortch, W.J. Wiseman, and B.K. Sen Gupta. 1996. Nutrient changes in the Mississippi River and system responses on the adjacent continental shelf. Estuaries 19(2):386–407, https://doi.org/10.2307/1352458.
Rafter, P.A., D.M. Sigman, C.D. Charles, J. Kaiser, and G.H. Haug. 2012. Subsurface tropical Pacific nitrogen isotopic composition of nitrate: Biogeochemical signals and their transport. Global Biogeochemical Cycles 26(1), https://doi.org/10.1029/2010GB003979.
Rafter, P.A., P.J. DiFiore, and D.M. Sigman. 2013. Coupled nitrate nitrogen and oxygen isotopes and organic matter remineralization in the Southern and Pacific Oceans. Journal of Geophysical Research: Oceans 118(10):4,781–4,794, https://doi.org/10.1002/jgrc.20316.
Rafter, P.A., D.M. Sigman, and K.R.M. Mackey. 2017. Recycled iron fuels new production in the eastern equatorial Pacific Ocean. Nature Communications 8(1):1100, https://doi.org/10.1038/s41467-017-01219-7.
Rafter, P.A., A. Bagnell, D. Marconi, and T. DeVries. 2019. Global trends in marine nitrate N isotopes from observations and a neural network-based climatology. Biogeosciences 16(13):2,617–2,633, https://doi.org/10.5194/bg-16-2617-2019.
Rafter, P.A. 2024. On the variability of equatorial Pacific nitrate and iron utilization. Oceanography 37(2):72–84, https://doi.org/10.5670/oceanog.2024.411.
Redfield, A.C., B.H. Ketchum, and F.A. Richards. 1963. The influence of organisms on the composition of seawater. Pp. 26–77 in The Sea, vol. 2. M.N. Hill, ed., Interscience, New York.
Resing, J.A., P.N. Sedwick, C.R. German, W.J. Jenkins, J.W. Moffett, B.M. Sohst, and A. Tagliabue. 2015. Basin-scale transport of hydrothermal dissolved metals across the South Pacific Ocean. Nature 523(7559):200–203, https://doi.org/10.1038/nature14577.
Rijkenberg, M.J.A., R. Middag, P. Laan, L.J.A. Gerringa, H.M. van Aken, V. Schoemann, J.T.M. de Jong, and H.J.W. de Baar. 2014. The distribution of dissolved iron in the West Atlantic Ocean. PLoS ONE 9(6):e101323, https://doi.org/10.1371/journal.pone.0101323.
Rohde, M.M., J. Granger, D.M. Sigman, and M.F. Lehmann. 2015. Coupled nitrate N and O stable isotope fractionation by a natural marine plankton consortium. Frontiers in Marine Science 2:28, https://doi.org/10.3389/fmars.2015.00028.
Romera-Castillo, C., R.T. Letscher, and D.A. Hansell. 2016. New nutrients exert fundamental control on dissolved organic carbon accumulation in the surface Atlantic Ocean. Proceedings of the National Academy of Sciences of the United States of America 113(38):10,497–10,502, https://doi.org/10.1073/pnas.1605344113.
Saito, M.A., M.R. McIlvin, D.M. Moran, A.E. Santoro, C.L. Dupont, P.A. Rafter, J.K. Saunders, D. Kaul, C.H. Lamborg, M. Westley, and others. 2020. Abundant nitrite-oxidizing metalloenzymes in the mesopelagic zone of the tropical Pacific Ocean. Nature Geoscience 13(5):355–362, https://doi.org/10.1038/s41561-020-0565-6.
Santos, I.R., X. Chen, A.L. Lecher, A.H. Sawyer, N. Moosdorf, V. Rodellas, J. Tamborski, H.-M. Cho, N. Dimova, R. Sugimoto, and others. 2021. Submarine groundwater discharge impacts on coastal nutrient biogeochemistry. Nature Reviews Earth & Environment 2(5):307–323, https://doi.org/10.1038/s43017-021-00152-0.
Seitzinger, S.P., E. Mayorga, A.F. Bouwman, C. Kroeze, A.H.W. Beusen, G. Billen, G. Van Drecht, E. Dumont, B M. Fekete, J. Garnier, and J.A. Harrison. 2010. Global river nutrient export: A scenario analysis of past and future trends. Global Biogeochemical Cycles 24(4), https://doi.org/10.1029/2009GB003587.
Shafiee, R.T., J.T. Snow, Q. Zhang, and R.E.M. Rickaby. 2019. Iron requirements and uptake strategies of the globally abundant marine ammonia-oxidising archaeon, Nitrosopumilus maritimus SCM1. The ISME Journal 13(9):2,295–2,305, https://doi.org/10.1038/s41396-019-0434-8.
Shao, Z., Y. Xu, H. Wang, W. Luo, L. Wang, Y. Huang, N.S.R. Agawin, A. Ahmed, M. Benavides, M. Bentzon-Tilia, and others. 2023. Global oceanic diazotroph database version 2 and elevated estimate of global oceanic N2 fixation. Earth System Science Data 15(8):3,673–3,709, https://doi.org/10.5194/essd-15-3673-2023.
Sharples, J., J.J. Middelburg, K. Fennel, and T.D. Jickells. 2017. What proportion of riverine nutrients reaches the open ocean? Global Biogeochemical Cycles 31(1):39–58, https://doi.org/10.1002/2016GB005483.
Sigman, D.M., M.A. Altabet, R. François, D.C. McCorkle, and G. Fischer. 1999. The δ15N of nitrate in the Southern Ocean: Consumption of nitrate in surface waters. Global Biogeochemical Cycles 13(4):1,149–1,166, https://doi.org/10.1029/1999GB900038.
Sigman, D.M., M.A. Altabet, D.C. McCorkle, R. François, and G. Fischer. 2000. The δ15N of nitrate in the Southern Ocean: Nitrogen cycling and circulation in the ocean interior. Journal of Geophysical Research: Oceans 105(C8):19,599–19,614, https://doi.org/10.1029/2000JC000265.
Sigman, D.M., J. Granger, P.J. DiFiore, M.M.F. Lehmann, R. Ho, G. Cane, and A. van Geen. 2005. Coupled nitrogen and oxygen isotope measurements of nitrate along the eastern North Pacific margin. Global Biogeochemical Cycles 19(4), https://doi.org/10.1029/2005GB002458.
Sigman, D.M., P.J. DiFiore, M.P. Hain, C. Deutsch, Y. Wang, D.M. Karl, A.N. Knapp, M.F. Lehman, S. Pantoja, and M.F. Lehmann. 2009. The dual isotopes of deep nitrate as a constraint on the cycle and budget of oceanic fixed nitrogen. Deep Sea Research Part I 56(9):1,419–1,439, https://doi.org/10.1016/j.dsr.2009.04.007.
Sigman, D.M., M.P. Hain, and G.H. Haug. 2010. The polar ocean and glacial cycles in atmospheric CO2 concentration. Nature 466(7302):47–55, https://doi.org/10.1038/nature09149.
Sigman, D.M., and F. Fripiat. 2019. Nitrogen isotopes in the ocean. Pp. 263–278 in Encyclopedia of Ocean Sciences. J.K. Cochran, H.J. Bokuniewicz, and P.L. Yager, eds, Elsevier, https://doi.org/10.1016/B978-0-12-409548-9.11605-7.
Smart, S.M., S.E. Fawcett, S.J. Thomalla, M.A. Weigand, C.J.C. Reason, and D.M. Sigman. 2015. Isotopic evidence for nitrification in the Antarctic winter mixed layer. Global Biogeochemical Cycles 29(4):427–445, https://doi.org/10.1002/2014GB005013.
Snow, J.T., D. Polyviou, P. Skipp, N.A.M. Chrismas, A. Hitchcock, R. Geider, C.M. Moore, and T.S. Bibby. 2015. Quantifying integrated proteomic responses to iron stress in the globally important marine diazotroph Trichodesmium. PLoS ONE 10(11):e0142626, https://doi.org/10.1371/journal.pone.0142626.
Sohm, J., and D. Capone. 2006. Phosphorus dynamics of the tropical and subtropical North Atlantic: Trichodesmium spp. versus bulk plankton. Marine Ecology Progress Series 317:21–28, https://doi.org/10.3354/meps317021.
Sohm, J.A., J.A. Hilton, A.E. Noble, J.P. Zehr, M.A. Saito, and E.A. Webb. 2011. Nitrogen fixation in the South Atlantic Gyre and the Benguela Upwelling System. Geophysical Research Letters 38(16), https://doi.org/10.1029/2011GL048315.
Somes, C.J., A. Schmittner, E.D. Galbraith, M.F. Lehmann, M.A. Altabet, J.P. Montoya, R.M. Letelier, A.C. Mix, A. Bourbonnais, and M. Eby. 2010. Simulating the global distribution of nitrogen isotopes in the ocean. Global Biogeochemical Cycles 24(4), https://doi.org/10.1029/2009gb003767.
Somes, C.J., A. Oschlies, and A. Schmittner. 2013. Isotopic constraints on the pre-industrial oceanic nitrogen budget. Biogeosciences 10(9):5,889–5,910, https://doi.org/10.5194/bg-10-5889-2013.
Stein, L.Y. 2019. Insights into the physiology of ammonia-oxidizing microorganisms. Current Opinion in Chemical Biology 49:9–15, https://doi.org/10.1016/j.cbpa.2018.09.003.
Subramaniam, A., P.L. Yager, E.J. Carpenter, C. Mahaffey, K. Björkman, S. Cooley, A.B. Kustka, J.P. Montoya, S.A. Sañudo-Wilhelmy, R. Shipe, and D.G. Capone. 2008. Amazon River enhances diazotrophy and carbon sequestration in the tropical North Atlantic Ocean. Proceedings of the National Academy of Sciences of the United States of America 105(30):10,460–10,465, https://doi.org/10.1073/pnas.0710279105.
Sun, X., C. Frey, and B.B. Ward. 2023. Nitrite oxidation across the full oxygen spectrum in the ocean. Global Biogeochemical Cycles 37(4):e2022GB007548, https://doi.org/10.1029/2022GB007548.
Tagliabue, A., L. Bopp, J.-C. Dutay, A.R. Bowie, F. Chever, P. Jean-Baptiste, E. Bucciarelli, D. Lannuzel, T. Remenyi, G. Sarthou, and others. 2010. Hydrothermal contribution to the oceanic dissolved iron inventory. Nature Geoscience 3(4):252–256, https://doi.org/10.1038/ngeo818.
Tagliabue, A., A.R. Bowie, T. DeVries, M.J. Ellwood, W.M. Landing, A. Milne, D.C. Ohnemus, B.S. Twining, and P.W. Boyd. 2019. The interplay between regeneration and scavenging fluxes drives ocean iron cycling. Nature Communications 10(1):4960, https://doi.org/10.1038/s41467-019-12775-5.
Tagliabue, A., A.R. Bowie, T. Holmes, P. Latour, P. van der Merwe, M. Gault-Ringold, K. Wuttig, and J.A. Resing. 2022. Constraining the contribution of hydrothermal iron to Southern Ocean export production using deep ocean iron observations. Frontiers in Marine Science 9:754517, https://doi.org/10.3389/fmars.2022.754517.
Torres-Valdes, S., V.M. Roussenov, R. Sanders, S. Reynolds, X. Pan, R. Mather, A. Landolfi, G.A. Wolff, E.P. Achterberg, and R.G. Williams. 2009. Distribution of dissolved organic nutrients and their effect on export production over the Atlantic Ocean. Global Biogeochemical Cycles 23(4), https://doi.org/10.1029/2008gb003389.
Tuerena, R.E., R.S. Ganeshram, W. Geibert, A.E. Fallick, J. Dougans, A. Tait, S.F. Henley, and E.M.S. Woodward. 2015. Nutrient cycling in the Atlantic basin: The evolution of nitrate isotope signatures in water masses. Global Biogeochemical Cycles 29(10):1,830–1,844, https://doi.org/10.1002/2015GB005164.
Turk-Kubo, K.A., M. Karamchandani, D.G. Capone, and J.P. Zehr. 2014. The paradox of marine heterotrophic nitrogen fixation: Abundances of heterotrophic diazotrophs do not account for nitrogen fixation rates in the eastern tropical South Pacific. Environmental Microbiology 16(10):3,095–3,114, https://doi.org/10.1111/1462-2920.12346.
Vieira, L.H., S. Krisch, M.J. Hopwood, A.J. Beck, J. Scholten, V. Liebetrau, and E.P. Achterberg. 2020. Unprecedented Fe delivery from the Congo River margin to the South Atlantic Gyre. Nature Communications 11(1):556, https://doi.org/10.1038/s41467-019-14255-2.
Voss, M., J.W. Dippner, and J.P. Montoya. 2001. Nitrogen isotope patterns in the oxygen-deficient waters of the Eastern Tropical North Pacific Ocean. Deep Sea Research Part I 48(8):1,905–1,921, https://doi.org/10.1016/S0967-0637(00)00110-2.
Wan, X.S., L. Hou, S.-J. Kao, Y. Zhang, H.-X. Sheng, H. Shen, S. Tong, W. Qin, and B.B. Ward. 2023. Pathways of N2O production by marine ammonia-oxidizing archaea determined from dual-isotope labeling. Proceedings of the National Academy of Sciences of the United States of America 120(11):e2220697120, https://doi.org/10.1073/pnas.2220697120.
Wang, W.L., J.K. Moore, A.C. Martiny, and F.W. Primeau. 2019. Convergent estimates of marine nitrogen fixation. Nature 566:205–211, https://doi.org/10.1038/s41586-019-0911-2.
Wankel, S.D., C. Kendall, J.T. Pennington, F.P. Chavez, and A. Paytan. 2007. Nitrification in the euphotic zone as evidenced by nitrate dual isotopic composition: Observations from Monterey Bay, California. Global Biogeochemical Cycles 21(2), https://doi.org/10.1029/2006GB002723.
Ward, B.B. 2013. Oceans. How nitrogen is lost. Science 341(6144):352–353, https://doi.org/10.1126/science.1240314.
Weber, T., and C. Deutsch. 2014. Local versus basin-scale limitation of marine nitrogen fixation. Proceedings of the National Academy of Sciences of the United States of America 111(24):8,741–8,746, https://doi.org/10.1073/pnas.1317193111.
Wei, X., N. Vajrala, L. Hauser, L.A. Sayavedra-Soto, and D.J. Arp. 2006. Iron nutrition and physiological responses to iron stress in Nitrosomonas europaea. Archives of Microbiology 186(2):107–118, https://doi.org/10.1007/s00203-006-0126-4.
Wen, Z., T.J. Browning, Y. Cai, R. Dai, R. Zhang, C. Du, R. Jiang, W. Lin, X. Liu, Z. Cao, and others. 2022. Nutrient regulation of biological nitrogen fixation across the tropical western North Pacific. Science Advances 8(5):eabl7564, https://doi.org/10.1126/sciadv.abl7564.
White, A.E., Y.H. Spitz, D.M. Karl, and R.M. Letelier. 2006. Flexible elemental stoichiometry in Trichodesmium spp. and its ecological implications. Limnology and Oceanography 51(4):1,777–1,790, https://doi.org/10.4319/lo.2006.51.4.1777.
White, A.E., J. Granger, C. Selden, M.R. Gradoville, L. Potts, A. Bourbonnais, R.W. Fulweiler, A.N. Knapp, W. Mohr, P.H. Moisander, and others. 2020. A critical review of the 15N2 tracer method to measure diazotrophic production in pelagic ecosystems. Limnology and Oceanography: Methods 18(4):129–147, https://doi.org/10.1002/lom3.10353.
Yang, S., and N. Gruber. 2016. The anthropogenic perturbation of the marine nitrogen cycle by atmospheric deposition: Nitrogen cycle feedbacks and the 15N Haber-Bosch effect. Global Biogeochemical Cycles 30(10):1,418–1,440, https://doi.org/10.1002/2016GB005421.
Yoshikawa, C., A. Makabe, T. Shiozaki, S. Toyoda, O. Yoshida, K. Furuya, and N. Yoshida. 2015. Nitrogen isotope ratios of nitrate and N* anomalies in the subtropical South Pacific. Geochemistry, Geophysics, Geosystems 16(5):1,439–1,448, https://doi.org/10.1002/2014GC005678.
Zehr, J.P., and D.G. Capone. 2020. Changing perspectives in marine nitrogen fixation. Science 368(6492), https://doi.org/10.1126/science.aay9514.
Zhang, R., X.T. Wang, H. Ren, J. Huang, M. Chen, and D.M. Sigman. 2020. Dissolved organic nitrogen cycling in the South China Sea from an isotopic perspective. Global Biogeochemical Cycles 34(12):e2020GB006551, https://doi.org/10.1029/2020GB006551.
Zumft, W.G. 1997. Cell biology and molecular basis of denitrification. Microbiology and Molecular Biology Reviews 61(4):533–616, https://doi.org/10.1128/mmbr.61.4.533-616.1997.