Articles | Volume 19, issue 3
https://doi.org/10.5194/bg-19-715-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-19-715-2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
07 Feb 2022
Research article |
| 07 Feb 2022
| 07 Feb 2022
Biogeochemical controls on ammonium accumulation in the surface layer of the Southern Ocean
Shantelle Smith
CORRESPONDING AUTHOR
Department of Oceanography, University of Cape Town, Private Bag X3,
Rondebosch, Cape Town, South Africa
Katye E. Altieri
Department of Oceanography, University of Cape Town, Private Bag X3,
Rondebosch, Cape Town, South Africa
Mhlangabezi Mdutyana
Department of Oceanography, University of Cape Town, Private Bag X3,
Rondebosch, Cape Town, South Africa
Southern Ocean Carbon and Climate Observatory (SOCCO), CSIR,
Rosebank, Cape Town, South Africa
David R. Walker
Department of Conservation and Marine Sciences, Cape Peninsula
University of Technology, Cape Town, South Africa
Ruan G. Parrott
Department of Oceanography, University of Cape Town, Private Bag X3,
Rondebosch, Cape Town, South Africa
Sedick Gallie
Department of Conservation and Marine Sciences, Cape Peninsula
University of Technology, Cape Town, South Africa
Kurt A. M. Spence
Department of Oceanography, University of Cape Town, Private Bag X3,
Rondebosch, Cape Town, South Africa
Jessica M. Burger
Department of Oceanography, University of Cape Town, Private Bag X3,
Rondebosch, Cape Town, South Africa
Sarah E. Fawcett
Department of Oceanography, University of Cape Town, Private Bag X3,
Rondebosch, Cape Town, South Africa
Marine and Antarctic Research centre for Innovation and
Sustainability (MARIS), University of Cape Town, Cape Town, South Africa
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Rebecca M. Garland, Katye E. Altieri, Laura Dawidowski, Laura Gallardo, Aderiana Mbandi, Nestor Y. Rojas, and N'datchoh E. Touré
Atmos. Chem. Phys., 24, 5757–5764, https://doi.org/10.5194/acp-24-5757-2024, https://doi.org/10.5194/acp-24-5757-2024, 2024
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This opinion piece focuses on two geographical areas in the Global South where the authors are based that are underrepresented in atmospheric science. This opinion provides context on common challenges and constraints, with suggestions on how the community can address these. The focus is on the strengths of atmospheric science research in these regions. It is these strengths, we believe, that highlight the critical role of Global South researchers in the future of atmospheric science research.
Weiyi Tang, Bess B. Ward, Michael Beman, Laura Bristow, Darren Clark, Sarah Fawcett, Claudia Frey, François Fripiat, Gerhard J. Herndl, Mhlangabezi Mdutyana, Fabien Paulot, Xuefeng Peng, Alyson E. Santoro, Takuhei Shiozaki, Eva Sintes, Charles Stock, Xin Sun, Xianhui S. Wan, Min N. Xu, and Yao Zhang
Earth Syst. Sci. Data, 15, 5039–5077, https://doi.org/10.5194/essd-15-5039-2023, https://doi.org/10.5194/essd-15-5039-2023, 2023
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Nitrification and nitrifiers play an important role in marine nitrogen and carbon cycles by converting ammonium to nitrite and nitrate. Nitrification could affect microbial community structure, marine productivity, and the production of nitrous oxide – a powerful greenhouse gas. We introduce the newly constructed database of nitrification and nitrifiers in the marine water column and guide future research efforts in field observations and model development of nitrification.
Jessica M. Burger, Emily Joyce, Meredith G. Hastings, Kurt A. M. Spence, and Katye E. Altieri
Atmos. Chem. Phys., 23, 5605–5622, https://doi.org/10.5194/acp-23-5605-2023, https://doi.org/10.5194/acp-23-5605-2023, 2023
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A seasonal analysis of the nitrogen isotopes of atmospheric nitrate over the remote Southern Ocean reveals that similar natural NOx sources dominate in spring and summer, while winter is representative of background-level conditions. The oxygen isotopes suggest that similar oxidation pathways involving more ozone occur in spring and winter, while the hydroxyl radical is the main oxidant in summer. This work helps to constrain NOx cycling and oxidant budgets in a data-sparse remote marine region.
Mhlangabezi Mdutyana, Tanya Marshall, Xin Sun, Jessica M. Burger, Sandy J. Thomalla, Bess B. Ward, and Sarah E. Fawcett
Biogeosciences, 19, 3425–3444, https://doi.org/10.5194/bg-19-3425-2022, https://doi.org/10.5194/bg-19-3425-2022, 2022
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Nitrite-oxidizing bacteria in the winter Southern Ocean show a high affinity for nitrite but require a minimum (i.e., "threshold") concentration before they increase their rates of nitrite oxidation significantly. The classic Michaelis–Menten model thus cannot be used to derive the kinetic parameters, so a modified equation was employed that also yields the threshold nitrite concentration. Dissolved iron availability may play an important role in limiting nitrite oxidation.
Jessica M. Burger, Julie Granger, Emily Joyce, Meredith G. Hastings, Kurt A. M. Spence, and Katye E. Altieri
Atmos. Chem. Phys., 22, 1081–1096, https://doi.org/10.5194/acp-22-1081-2022, https://doi.org/10.5194/acp-22-1081-2022, 2022
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The nitrogen (N) isotopic composition of atmospheric nitrate in the Southern Ocean (SO) marine boundary layer (MBL) reveals the importance of oceanic alkyl nitrate emissions as a source of reactive N to the atmosphere. The oxygen isotopic composition suggests peroxy radicals contribute up to 63 % to NO oxidation and that nitrate forms via the OH pathway. This work improves our understanding of reactive N sources and cycling in a remote marine region, a proxy for the pre-industrial atmosphere.
Sebastian Landwehr, Michele Volpi, F. Alexander Haumann, Charlotte M. Robinson, Iris Thurnherr, Valerio Ferracci, Andrea Baccarini, Jenny Thomas, Irina Gorodetskaya, Christian Tatzelt, Silvia Henning, Rob L. Modini, Heather J. Forrer, Yajuan Lin, Nicolas Cassar, Rafel Simó, Christel Hassler, Alireza Moallemi, Sarah E. Fawcett, Neil Harris, Ruth Airs, Marzieh H. Derkani, Alberto Alberello, Alessandro Toffoli, Gang Chen, Pablo Rodríguez-Ros, Marina Zamanillo, Pau Cortés-Greus, Lei Xue, Conor G. Bolas, Katherine C. Leonard, Fernando Perez-Cruz, David Walton, and Julia Schmale
Earth Syst. Dynam., 12, 1295–1369, https://doi.org/10.5194/esd-12-1295-2021, https://doi.org/10.5194/esd-12-1295-2021, 2021
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The Antarctic Circumnavigation Expedition surveyed a large number of variables describing the dynamic state of ocean and atmosphere, freshwater cycle, atmospheric chemistry, ocean biogeochemistry, and microbiology in the Southern Ocean. To reduce the dimensionality of the dataset, we apply a sparse principal component analysis and identify temporal patterns from diurnal to seasonal cycles, as well as geographical gradients and
hotspotsof interaction. Code and data are open access.
Raquel F. Flynn, Thomas G. Bornman, Jessica M. Burger, Shantelle Smith, Kurt A. M. Spence, and Sarah E. Fawcett
Biogeosciences, 18, 6031–6059, https://doi.org/10.5194/bg-18-6031-2021, https://doi.org/10.5194/bg-18-6031-2021, 2021
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Biological activity in the shallow Weddell Sea affects the biogeochemistry of recently formed deep waters. To investigate the drivers of carbon and nutrient export, we measured rates of primary production and nitrogen uptake, characterized the phytoplankton community, and estimated nutrient depletion ratios across the under-sampled western Weddell Sea in mid-summer. Carbon export was highest at the ice shelves and was determined by a combination of physical, chemical, and biological factors.
Alex R. Baker, Maria Kanakidou, Katye E. Altieri, Nikos Daskalakis, Gregory S. Okin, Stelios Myriokefalitakis, Frank Dentener, Mitsuo Uematsu, Manmohan M. Sarin, Robert A. Duce, James N. Galloway, William C. Keene, Arvind Singh, Lauren Zamora, Jean-Francois Lamarque, Shih-Chieh Hsu, Shital S. Rohekar, and Joseph M. Prospero
Atmos. Chem. Phys., 17, 8189–8210, https://doi.org/10.5194/acp-17-8189-2017, https://doi.org/10.5194/acp-17-8189-2017, 2017
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Man's activities have greatly increased the amount of nitrogen emitted into the atmosphere. Some of this nitrogen is transported to the world's oceans, where it may affect microscopic marine plants and cause ecological problems. The huge size of the oceans makes direct monitoring of nitrogen inputs impossible, so computer models must be used to assess this issue. We find that current models reproduce observed nitrogen deposition to the oceans reasonably well and recommend future improvements.
Angela N. Knapp, Sarah E. Fawcett, Alfredo Martínez-Garcia, Nathalie Leblond, Thierry Moutin, and Sophie Bonnet
Biogeosciences, 13, 4645–4657, https://doi.org/10.5194/bg-13-4645-2016, https://doi.org/10.5194/bg-13-4645-2016, 2016
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The goal of this manuscript was to track the fate of newly fixed nitrogen (N) in large volume mesocosms in the coastal waters of New Caledonia. We used a N isotope ("δ15N") budget and found a shift in the δ15N of sinking particulate N over the 23-day experiment, indicating that nitrate supported export production at the beginning of the experiment, but that nitrogen fixation supported export at the end. We infer that nitrogen fixation supported export production by a release of dissolved N.
Sophie Bonnet, Hugo Berthelot, Kendra Turk-Kubo, Sarah Fawcett, Eyal Rahav, Stéphane L'Helguen, and Ilana Berman-Frank
Biogeosciences, 13, 2653–2673, https://doi.org/10.5194/bg-13-2653-2016, https://doi.org/10.5194/bg-13-2653-2016, 2016
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N2 fixation rates were measured daily in ~ 50 m3 mesocosms deployed in New Caledonia to investigate the high-frequency dynamics of diazotrophy and the fate of diazotroph-derived nitrogen (DDN) oligotrophic ecosystems. ~ 10 % of UCYN-C from the water column were exported daily to the traps, representing as much as 22.4 ± 5.5 % of the total POC exported at the height of the UCYN-C bloom. 16 ± 6 % of the DDN was released to the dissolved pool and 21 ± 4 % was transferred to non-diazotrophic plankton.
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Biogeosciences, 21, 4007–4035, https://doi.org/10.5194/bg-21-4007-2024, https://doi.org/10.5194/bg-21-4007-2024, 2024
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Biogeosciences, 21, 3903–3926, https://doi.org/10.5194/bg-21-3903-2024, https://doi.org/10.5194/bg-21-3903-2024, 2024
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Despite the ocean’s importance in the carbon cycle and hence the climate, observing the ocean carbon sink remains challenging. Here, I use an ensemble of 12 models to understand drivers of decadal trends of the past, present, and future ocean carbon sink. I show that 80 % of the decadal trends in the multi-model mean ocean carbon sink can be explained by changes in decadal trends in atmospheric CO2. The remaining 20 % are due to internal climate variability and ocean heat uptake.
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Biogeosciences, 21, 3839–3867, https://doi.org/10.5194/bg-21-3839-2024, https://doi.org/10.5194/bg-21-3839-2024, 2024
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Biogeosciences, 21, 3463–3475, https://doi.org/10.5194/bg-21-3463-2024, https://doi.org/10.5194/bg-21-3463-2024, 2024
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We investigate the effects of mineral grain size and seawater salinity on magnesium hydroxide dissolution and calcium carbonate precipitation kinetics for ocean alkalinity enhancement. Salinity did not affect the dissolution, but calcium carbonate formed earlier at lower salinities due to the lower magnesium and dissolved organic carbon concentrations. Smaller grain sizes dissolved faster but calcium carbonate precipitated earlier, suggesting that medium grain sizes are optimal for kinetics.
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Biogeosciences, 21, 3121–3141, https://doi.org/10.5194/bg-21-3121-2024, https://doi.org/10.5194/bg-21-3121-2024, 2024
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Biogeosciences, 21, 2859–2876, https://doi.org/10.5194/bg-21-2859-2024, https://doi.org/10.5194/bg-21-2859-2024, 2024
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Our planet is facing a climate crisis. Scientists are working on innovative solutions that will aid in capturing the hard to abate emissions before it is too late. Exciting research reveals that ocean alkalinity enhancement, a key climate change mitigation strategy, does not harm phytoplankton, the cornerstone of marine ecosystems. Through meticulous study, we may have uncovered a positive relationship: up to a specific limit, enhancing ocean alkalinity boosts photosynthesis by certain species.
France Van Wambeke, Pascal Conan, Mireille Pujo-Pay, Vincent Taillandier, Olivier Crispi, Alexandra Pavlidou, Sandra Nunige, Morgane Didry, Christophe Salmeron, and Elvira Pulido-Villena
Biogeosciences, 21, 2621–2640, https://doi.org/10.5194/bg-21-2621-2024, https://doi.org/10.5194/bg-21-2621-2024, 2024
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Phosphomonoesterase (PME) and phosphodiesterase (PDE) activities over the epipelagic zone are described in the eastern Mediterranean Sea in winter and autumn. The types of concentration kinetics obtained for PDE (saturation at 50 µM, high Km, high turnover times) compared to those of PME (saturation at 1 µM, low Km, low turnover times) are discussed in regard to the possible inequal distribution of PDE and PME in the size continuum of organic material and accessibility to phosphodiesters.
Jenny Hieronymus, Magnus Hieronymus, Matthias Gröger, Jörg Schwinger, Raffaele Bernadello, Etienne Tourigny, Valentina Sicardi, Itzel Ruvalcaba Baroni, and Klaus Wyser
Biogeosciences, 21, 2189–2206, https://doi.org/10.5194/bg-21-2189-2024, https://doi.org/10.5194/bg-21-2189-2024, 2024
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The timing of the net primary production annual maxima in the North Atlantic in the period 1750–2100 is investigated using two Earth system models and the high-emissions scenario SSP5-8.5. It is found that, for most of the region, the annual maxima occur progressively earlier, with the most change occurring after the year 2000. Shifts in the seasonality of the primary production may impact the entire ecosystem, which highlights the need for long-term monitoring campaigns in this area.
Nicole M. Travis, Colette L. Kelly, and Karen L. Casciotti
Biogeosciences, 21, 1985–2004, https://doi.org/10.5194/bg-21-1985-2024, https://doi.org/10.5194/bg-21-1985-2024, 2024
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We conducted experimental manipulations of light level on microbial communities from the primary nitrite maximum. Overall, while individual microbial processes have different directions and magnitudes in their response to increasing light, the net community response is a decline in nitrite production with increasing light. We conclude that while increased light may decrease net nitrite production, high-light conditions alone do not exclude nitrification from occurring in the surface ocean.
Zoë Rebecca van Kemenade, Zeynep Erdem, Ellen Christine Hopmans, Jaap Smede Sinninghe Damsté, and Darci Rush
Biogeosciences, 21, 1517–1532, https://doi.org/10.5194/bg-21-1517-2024, https://doi.org/10.5194/bg-21-1517-2024, 2024
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The California Current system (CCS) hosts the eastern subtropical North Pacific oxygen minimum zone (ESTNP OMZ). This study shows anaerobic ammonium oxidizing (anammox) bacteria cause a loss of bioavailable nitrogen (N) in the ESTNP OMZ throughout the late Quaternary. Anammox occurred during both glacial and interglacial periods and was driven by the supply of organic matter and changes in ocean currents. These findings may have important consequences for biogeochemical models of the CCS.
Cathy Wimart-Rousseau, Tobias Steinhoff, Birgit Klein, Henry Bittig, and Arne Körtzinger
Biogeosciences, 21, 1191–1211, https://doi.org/10.5194/bg-21-1191-2024, https://doi.org/10.5194/bg-21-1191-2024, 2024
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The marine CO2 system can be measured independently and continuously by BGC-Argo floats since numerous pH sensors have been developed to suit these autonomous measurements platforms. By applying the Argo correction routines to float pH data acquired in the subpolar North Atlantic Ocean, we report the uncertainty and lack of objective criteria associated with the choice of the reference method as well the reference depth for the pH correction.
Sabine Mecking and Kyla Drushka
Biogeosciences, 21, 1117–1133, https://doi.org/10.5194/bg-21-1117-2024, https://doi.org/10.5194/bg-21-1117-2024, 2024
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This study investigates whether northeastern North Pacific oxygen changes may be caused by surface density changes in the northwest as water moves along density horizons from the surface into the subsurface ocean. A correlation is found with a lag that about matches the travel time of water from the northwest to the northeast. Salinity is the main driver causing decadal changes in surface density, whereas salinity and temperature contribute about equally to long-term declining density trends.
Takamitsu Ito, Hernan E. Garcia, Zhankun Wang, Shoshiro Minobe, Matthew C. Long, Just Cebrian, James Reagan, Tim Boyer, Christopher Paver, Courtney Bouchard, Yohei Takano, Seth Bushinsky, Ahron Cervania, and Curtis A. Deutsch
Biogeosciences, 21, 747–759, https://doi.org/10.5194/bg-21-747-2024, https://doi.org/10.5194/bg-21-747-2024, 2024
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This study aims to estimate how much oceanic oxygen has been lost and its uncertainties. One major source of uncertainty comes from the statistical gap-filling methods. Outputs from Earth system models are used to generate synthetic observations where oxygen data are extracted from the model output at the location and time of historical oceanographic cruises. Reconstructed oxygen trend is approximately two-thirds of the true trend.
Robert W. Izett, Katja Fennel, Adam C. Stoer, and David P. Nicholson
Biogeosciences, 21, 13–47, https://doi.org/10.5194/bg-21-13-2024, https://doi.org/10.5194/bg-21-13-2024, 2024
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This paper provides an overview of the capacity to expand the global coverage of marine primary production estimates using autonomous ocean-going instruments, called Biogeochemical-Argo floats. We review existing approaches to quantifying primary production using floats, provide examples of the current implementation of the methods, and offer insights into how they can be better exploited. This paper is timely, given the ongoing expansion of the Biogeochemical-Argo array.
Qian Liu, Yingjie Liu, and Xiaofeng Li
Biogeosciences, 20, 4857–4874, https://doi.org/10.5194/bg-20-4857-2023, https://doi.org/10.5194/bg-20-4857-2023, 2023
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In the Southern Ocean, abundant eddies behave opposite to our expectations. That is, anticyclonic (cyclonic) eddies are cold (warm). By investigating the variations of physical and biochemical parameters in eddies, we find that abnormal eddies have unique and significant effects on modulating the parameters. This study fills a gap in understanding the effects of abnormal eddies on physical and biochemical parameters in the Southern Ocean.
Caroline Ulses, Claude Estournel, Patrick Marsaleix, Karline Soetaert, Marine Fourrier, Laurent Coppola, Dominique Lefèvre, Franck Touratier, Catherine Goyet, Véronique Guglielmi, Fayçal Kessouri, Pierre Testor, and Xavier Durrieu de Madron
Biogeosciences, 20, 4683–4710, https://doi.org/10.5194/bg-20-4683-2023, https://doi.org/10.5194/bg-20-4683-2023, 2023
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Deep convection plays a key role in the circulation, thermodynamics, and biogeochemical cycles in the Mediterranean Sea, considered to be a hotspot of biodiversity and climate change. In this study, we investigate the seasonal and annual budget of dissolved inorganic carbon in the deep-convection area of the northwestern Mediterranean Sea.
Daniela König and Alessandro Tagliabue
Biogeosciences, 20, 4197–4212, https://doi.org/10.5194/bg-20-4197-2023, https://doi.org/10.5194/bg-20-4197-2023, 2023
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Using model simulations, we show that natural and anthropogenic changes in the global climate leave a distinct fingerprint in the isotopic signatures of iron in the surface ocean. We find that these climate effects on iron isotopes are often caused by the redistribution of iron from different external sources to the ocean, due to changes in ocean currents, and by changes in algal growth, which take up iron. Thus, isotopes may help detect climate-induced changes in iron supply and algal uptake.
Chloé Baumas, Robin Fuchs, Marc Garel, Jean-Christophe Poggiale, Laurent Memery, Frédéric A. C. Le Moigne, and Christian Tamburini
Biogeosciences, 20, 4165–4182, https://doi.org/10.5194/bg-20-4165-2023, https://doi.org/10.5194/bg-20-4165-2023, 2023
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Through the sink of particles in the ocean, carbon (C) is exported and sequestered when reaching 1000 m. Attempts to quantify C exported vs. C consumed by heterotrophs have increased. Yet most of the conducted estimations have led to C demands several times higher than C export. The choice of parameters greatly impacts the results. As theses parameters are overlooked, non-accurate values are often used. In this study we show that C budgets can be well balanced when using appropriate values.
Anna Belcher, Sian F. Henley, Katharine Hendry, Marianne Wootton, Lisa Friberg, Ursula Dallman, Tong Wang, Christopher Coath, and Clara Manno
Biogeosciences, 20, 3573–3591, https://doi.org/10.5194/bg-20-3573-2023, https://doi.org/10.5194/bg-20-3573-2023, 2023
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The oceans play a crucial role in the uptake of atmospheric carbon dioxide, particularly the Southern Ocean. The biological pumping of carbon from the surface to the deep ocean is key to this. Using sediment trap samples from the Scotia Sea, we examine biogeochemical fluxes of carbon, nitrogen, and biogenic silica and their stable isotope compositions. We find phytoplankton community structure and physically mediated processes are important controls on particulate fluxes to the deep ocean.
Asmita Singh, Susanne Fietz, Sandy J. Thomalla, Nicolas Sanchez, Murat V. Ardelan, Sébastien Moreau, Hanna M. Kauko, Agneta Fransson, Melissa Chierici, Saumik Samanta, Thato N. Mtshali, Alakendra N. Roychoudhury, and Thomas J. Ryan-Keogh
Biogeosciences, 20, 3073–3091, https://doi.org/10.5194/bg-20-3073-2023, https://doi.org/10.5194/bg-20-3073-2023, 2023
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Despite the scarcity of iron in the Southern Ocean, seasonal blooms occur due to changes in nutrient and light availability. Surprisingly, during an autumn bloom in the Antarctic sea-ice zone, the results from incubation experiments showed no significant photophysiological response of phytoplankton to iron addition. This suggests that ambient iron concentrations were sufficient, challenging the notion of iron deficiency in the Southern Ocean through extended iron-replete post-bloom conditions.
Benoît Pasquier, Mark Holzer, Matthew A. Chamberlain, Richard J. Matear, Nathaniel L. Bindoff, and François W. Primeau
Biogeosciences, 20, 2985–3009, https://doi.org/10.5194/bg-20-2985-2023, https://doi.org/10.5194/bg-20-2985-2023, 2023
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Modeling the ocean's carbon and oxygen cycles accurately is challenging. Parameter optimization improves the fit to observed tracers but can introduce artifacts in the biological pump. Organic-matter production and subsurface remineralization rates adjust to compensate for circulation biases, changing the pathways and timescales with which nutrients return to the surface. Circulation biases can thus strongly alter the system’s response to ecological change, even when parameters are optimized.
Priyanka Banerjee
Biogeosciences, 20, 2613–2643, https://doi.org/10.5194/bg-20-2613-2023, https://doi.org/10.5194/bg-20-2613-2023, 2023
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This study shows that atmospheric deposition is the most important source of iron to the upper northern Indian Ocean for phytoplankton growth. This is followed by iron from continental-shelf sediment. Phytoplankton increase following iron addition is possible only with high background levels of nitrate. Vertical mixing is the most important physical process supplying iron to the upper ocean in this region throughout the year. The importance of ocean currents in supplying iron varies seasonally.
Iris Kriest, Julia Getzlaff, Angela Landolfi, Volkmar Sauerland, Markus Schartau, and Andreas Oschlies
Biogeosciences, 20, 2645–2669, https://doi.org/10.5194/bg-20-2645-2023, https://doi.org/10.5194/bg-20-2645-2023, 2023
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Global biogeochemical ocean models are often subjectively assessed and tuned against observations. We applied different strategies to calibrate a global model against observations. Although the calibrated models show similar tracer distributions at the surface, they differ in global biogeochemical fluxes, especially in global particle flux. Simulated global volume of oxygen minimum zones varies strongly with calibration strategy and over time, rendering its temporal extrapolation difficult.
John C. Tracey, Andrew R. Babbin, Elizabeth Wallace, Xin Sun, Katherine L. DuRussel, Claudia Frey, Donald E. Martocello III, Tyler Tamasi, Sergey Oleynik, and Bess B. Ward
Biogeosciences, 20, 2499–2523, https://doi.org/10.5194/bg-20-2499-2023, https://doi.org/10.5194/bg-20-2499-2023, 2023
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Nitrogen (N) is essential for life; thus, its availability plays a key role in determining marine productivity. Using incubations of seawater spiked with a rare form of N measurable on a mass spectrometer, we quantified microbial pathways that determine marine N availability. The results show that pathways that recycle N have higher rates than those that result in its loss from biomass and present new evidence for anaerobic nitrite oxidation, a process long thought to be strictly aerobic.
Amanda Gerotto, Hongrui Zhang, Renata Hanae Nagai, Heather M. Stoll, Rubens César Lopes Figueira, Chuanlian Liu, and Iván Hernández-Almeida
Biogeosciences, 20, 1725–1739, https://doi.org/10.5194/bg-20-1725-2023, https://doi.org/10.5194/bg-20-1725-2023, 2023
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Based on the analysis of the response of coccolithophores’ morphological attributes in a laboratory dissolution experiment and surface sediment samples from the South China Sea, we proposed that the thickness shape (ks) factor of fossil coccoliths together with the normalized ks variation, which is the ratio of the standard deviation of ks (σ) over the mean ks (σ/ks), is a robust and novel proxy to reconstruct past changes in deep ocean carbon chemistry.
Katherine E. Turner, Doug M. Smith, Anna Katavouta, and Richard G. Williams
Biogeosciences, 20, 1671–1690, https://doi.org/10.5194/bg-20-1671-2023, https://doi.org/10.5194/bg-20-1671-2023, 2023
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We present a new method for reconstructing ocean carbon using climate models and temperature and salinity observations. To test this method, we reconstruct modelled carbon using synthetic observations consistent with current sampling programmes. Sensitivity tests show skill in reconstructing carbon trends and variability within the upper 2000 m. Our results indicate that this method can be used for a new global estimate for ocean carbon content.
Alexandre Mignot, Hervé Claustre, Gianpiero Cossarini, Fabrizio D'Ortenzio, Elodie Gutknecht, Julien Lamouroux, Paolo Lazzari, Coralie Perruche, Stefano Salon, Raphaëlle Sauzède, Vincent Taillandier, and Anna Teruzzi
Biogeosciences, 20, 1405–1422, https://doi.org/10.5194/bg-20-1405-2023, https://doi.org/10.5194/bg-20-1405-2023, 2023
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Numerical models of ocean biogeochemistry are becoming a major tool to detect and predict the impact of climate change on marine resources and monitor ocean health. Here, we demonstrate the use of the global array of BGC-Argo floats for the assessment of biogeochemical models. We first detail the handling of the BGC-Argo data set for model assessment purposes. We then present 23 assessment metrics to quantify the consistency of BGC model simulations with respect to BGC-Argo data.
Alban Planchat, Lester Kwiatkowski, Laurent Bopp, Olivier Torres, James R. Christian, Momme Butenschön, Tomas Lovato, Roland Séférian, Matthew A. Chamberlain, Olivier Aumont, Michio Watanabe, Akitomo Yamamoto, Andrew Yool, Tatiana Ilyina, Hiroyuki Tsujino, Kristen M. Krumhardt, Jörg Schwinger, Jerry Tjiputra, John P. Dunne, and Charles Stock
Biogeosciences, 20, 1195–1257, https://doi.org/10.5194/bg-20-1195-2023, https://doi.org/10.5194/bg-20-1195-2023, 2023
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Ocean alkalinity is critical to the uptake of atmospheric carbon and acidification in surface waters. We review the representation of alkalinity and the associated calcium carbonate cycle in Earth system models. While many parameterizations remain present in the latest generation of models, there is a general improvement in the simulated alkalinity distribution. This improvement is related to an increase in the export of biotic calcium carbonate, which closer resembles observations.
Jérôme Pinti, Tim DeVries, Tommy Norin, Camila Serra-Pompei, Roland Proud, David A. Siegel, Thomas Kiørboe, Colleen M. Petrik, Ken H. Andersen, Andrew S. Brierley, and André W. Visser
Biogeosciences, 20, 997–1009, https://doi.org/10.5194/bg-20-997-2023, https://doi.org/10.5194/bg-20-997-2023, 2023
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Large numbers of marine organisms such as zooplankton and fish perform daily vertical migration between the surface (at night) and the depths (in the daytime). This fascinating migration is important for the carbon cycle, as these organisms actively bring carbon to depths where it is stored away from the atmosphere for a long time. Here, we quantify the contributions of different animals to this carbon drawdown and storage and show that fish are important to the biological carbon pump.
Alastair J. M. Lough, Alessandro Tagliabue, Clément Demasy, Joseph A. Resing, Travis Mellett, Neil J. Wyatt, and Maeve C. Lohan
Biogeosciences, 20, 405–420, https://doi.org/10.5194/bg-20-405-2023, https://doi.org/10.5194/bg-20-405-2023, 2023
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Iron is a key nutrient for ocean primary productivity. Hydrothermal vents are a source of iron to the oceans, but the size of this source is poorly understood. This study examines the variability in iron inputs between hydrothermal vents in different geological settings. The vents studied release different amounts of Fe, resulting in plumes with similar dissolved iron concentrations but different particulate concentrations. This will help to refine modelling of iron-limited ocean productivity.
Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, and Karen L. Casciotti
Biogeosciences, 20, 325–347, https://doi.org/10.5194/bg-20-325-2023, https://doi.org/10.5194/bg-20-325-2023, 2023
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The primary nitrite maximum is a ubiquitous upper ocean feature where nitrite accumulates, but we still do not understand its formation and the co-occurring microbial processes involved. Using correlative methods and rates measurements, we found strong spatial patterns between environmental conditions and depths of the nitrite maxima, but not the maximum concentrations. Nitrification was the dominant source of nitrite, with occasional high nitrite production from phytoplankton near the coast.
Natacha Le Grix, Jakob Zscheischler, Keith B. Rodgers, Ryohei Yamaguchi, and Thomas L. Frölicher
Biogeosciences, 19, 5807–5835, https://doi.org/10.5194/bg-19-5807-2022, https://doi.org/10.5194/bg-19-5807-2022, 2022
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Compound events threaten marine ecosystems. Here, we investigate the potentially harmful combination of marine heatwaves with low phytoplankton productivity. Using satellite-based observations, we show that these compound events are frequent in the low latitudes. We then investigate the drivers of these compound events using Earth system models. The models share similar drivers in the low latitudes but disagree in the high latitudes due to divergent factors limiting phytoplankton production.
Abigale M. Wyatt, Laure Resplandy, and Adrian Marchetti
Biogeosciences, 19, 5689–5705, https://doi.org/10.5194/bg-19-5689-2022, https://doi.org/10.5194/bg-19-5689-2022, 2022
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Marine heat waves (MHWs) are a frequent event in the northeast Pacific, with a large impact on the region's ecosystems. Large phytoplankton in the North Pacific Transition Zone are greatly affected by decreased nutrients, with less of an impact in the Alaskan Gyre. For small phytoplankton, MHWs increase the spring small phytoplankton population in both regions thanks to reduced light limitation. In both zones, this results in a significant decrease in the ratio of large to small phytoplankton.
Margot C. F. Debyser, Laetitia Pichevin, Robyn E. Tuerena, Paul A. Dodd, Antonia Doncila, and Raja S. Ganeshram
Biogeosciences, 19, 5499–5520, https://doi.org/10.5194/bg-19-5499-2022, https://doi.org/10.5194/bg-19-5499-2022, 2022
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We focus on the exchange of key nutrients for algae production between the Arctic and Atlantic oceans through the Fram Strait. We show that the export of dissolved silicon here is controlled by the availability of nitrate which is influenced by denitrification on Arctic shelves. We suggest that any future changes in the river inputs of silica and changes in denitrification due to climate change will impact the amount of silicon exported, with impacts on Atlantic algal productivity and ecology.
Emily J. Zakem, Barbara Bayer, Wei Qin, Alyson E. Santoro, Yao Zhang, and Naomi M. Levine
Biogeosciences, 19, 5401–5418, https://doi.org/10.5194/bg-19-5401-2022, https://doi.org/10.5194/bg-19-5401-2022, 2022
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We use a microbial ecosystem model to quantitatively explain the mechanisms controlling observed relative abundances and nitrification rates of ammonia- and nitrite-oxidizing microorganisms in the ocean. We also estimate how much global carbon fixation can be associated with chemoautotrophic nitrification. Our results improve our understanding of the controls on nitrification, laying the groundwork for more accurate predictions in global climate models.
Zuozhu Wen, Thomas J. Browning, Rongbo Dai, Wenwei Wu, Weiying Li, Xiaohua Hu, Wenfang Lin, Lifang Wang, Xin Liu, Zhimian Cao, Haizheng Hong, and Dalin Shi
Biogeosciences, 19, 5237–5250, https://doi.org/10.5194/bg-19-5237-2022, https://doi.org/10.5194/bg-19-5237-2022, 2022
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Fe and P are key factors controlling the biogeography and activity of marine N2-fixing microorganisms. We found lower abundance and activity of N2 fixers in the northern South China Sea than around the western boundary of the North Pacific, and N2 fixation rates switched from Fe–P co-limitation to P limitation. We hypothesize the Fe supply rates and Fe utilization strategies of each N2 fixer are important in regulating spatial variability in community structure across the study area.
Claudia Eisenring, Sophy E. Oliver, Samar Khatiwala, and Gregory F. de Souza
Biogeosciences, 19, 5079–5106, https://doi.org/10.5194/bg-19-5079-2022, https://doi.org/10.5194/bg-19-5079-2022, 2022
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Given the sparsity of observational constraints on micronutrients such as zinc (Zn), we assess the sensitivities of a framework for objective parameter optimisation in an oceanic Zn cycling model. Our ensemble of optimisations towards synthetic data with varying kinds of uncertainty shows that deficiencies related to model complexity and the choice of the misfit function generally have a greater impact on the retrieval of model Zn uptake behaviour than does the limitation of data coverage.
Yoshikazu Sasai, Sherwood Lan Smith, Eko Siswanto, Hideharu Sasaki, and Masami Nonaka
Biogeosciences, 19, 4865–4882, https://doi.org/10.5194/bg-19-4865-2022, https://doi.org/10.5194/bg-19-4865-2022, 2022
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We have investigated the adaptive response of phytoplankton growth to changing light, nutrients, and temperature over the North Pacific using two physical-biological models. We compare modeled chlorophyll and primary production from an inflexible control model (InFlexPFT), which assumes fixed carbon (C):nitrogen (N):chlorophyll (Chl) ratios, to a recently developed flexible phytoplankton functional type model (FlexPFT), which incorporates photoacclimation and variable C:N:Chl ratios.
Jens Terhaar, Thomas L. Frölicher, and Fortunat Joos
Biogeosciences, 19, 4431–4457, https://doi.org/10.5194/bg-19-4431-2022, https://doi.org/10.5194/bg-19-4431-2022, 2022
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Estimates of the ocean sink of anthropogenic carbon vary across various approaches. We show that the global ocean carbon sink can be estimated by three parameters, two of which approximate the ocean ventilation in the Southern Ocean and the North Atlantic, and one of which approximates the chemical capacity of the ocean to take up carbon. With observations of these parameters, we estimate that the global ocean carbon sink is 10 % larger than previously assumed, and we cut uncertainties in half.
Natasha René van Horsten, Hélène Planquette, Géraldine Sarthou, Thomas James Ryan-Keogh, Nolwenn Lemaitre, Thato Nicholas Mtshali, Alakendra Roychoudhury, and Eva Bucciarelli
Biogeosciences, 19, 3209–3224, https://doi.org/10.5194/bg-19-3209-2022, https://doi.org/10.5194/bg-19-3209-2022, 2022
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The remineralisation proxy, barite, was measured along 30°E in the southern Indian Ocean during early austral winter. To our knowledge this is the first reported Southern Ocean winter study. Concentrations throughout the water column were comparable to observations during spring to autumn. By linking satellite primary production to this proxy a possible annual timescale is proposed. These findings also suggest possible carbon remineralisation from satellite data on a basin scale.
Zhibo Shao and Ya-Wei Luo
Biogeosciences, 19, 2939–2952, https://doi.org/10.5194/bg-19-2939-2022, https://doi.org/10.5194/bg-19-2939-2022, 2022
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Non-cyanobacterial diazotrophs (NCDs) may be an important player in fixing N2 in the ocean. By conducting meta-analyses, we found that a representative marine NCD phylotype, Gamma A, tends to inhabit ocean environments with high productivity, low iron concentration and high light intensity. It also appears to be more abundant inside cyclonic eddies. Our study suggests a niche differentiation of NCDs from cyanobacterial diazotrophs as the latter prefers low-productivity and high-iron oceans.
Coraline Leseurre, Claire Lo Monaco, Gilles Reverdin, Nicolas Metzl, Jonathan Fin, Claude Mignon, and Léa Benito
Biogeosciences, 19, 2599–2625, https://doi.org/10.5194/bg-19-2599-2022, https://doi.org/10.5194/bg-19-2599-2022, 2022
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Decadal trends of fugacity of CO2 (fCO2), total alkalinity (AT), total carbon (CT) and pH in surface waters are investigated in different domains of the southern Indian Ocean (45°S–57°S) from ongoing and station observations regularly conducted in summer over the period 1998–2019. The fCO2 increase and pH decrease are mainly driven by anthropogenic CO2 estimated just below the summer mixed layer, as well as by a warming south of the polar front or in the fertilized waters near Kerguelen Island.
Priscilla Le Mézo, Jérôme Guiet, Kim Scherrer, Daniele Bianchi, and Eric Galbraith
Biogeosciences, 19, 2537–2555, https://doi.org/10.5194/bg-19-2537-2022, https://doi.org/10.5194/bg-19-2537-2022, 2022
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This study quantifies the role of commercially targeted fish biomass in the cycling of three important nutrients (N, P, and Fe), relative to nutrients otherwise available in water and to nutrients required by primary producers, and the impact of fishing. We use a model of commercially targeted fish biomass constrained by fish catch and stock assessment data to assess the contributions of fish at the global scale, at the time of the global peak catch and prior to industrial fishing.
Cited articles
Aarnos, H., Ylöstalo, P., and Vähätalo, A. V.: Seasonal
phototransformation of dissolved organic matter to ammonium, dissolved
inorganic carbon, and labile substrates supporting bacterial biomass across
the Baltic Sea, J. Geophys. Res.-Biogeo., 117, https://doi.org/10.1029/2010JG001633, 2012.
Altabet, M. A.: Variations in nitrogen isotopic composition between sinking
and suspended particles: Implications for nitrogen cycling and particle
transformation in the open ocean, Deep-Sea Res., 35, 535–554,
https://doi.org/10.1016/0198-0149(88)90130-6, 1988.
Altieri, K. E., Spence, K. A. M., and Smith, S.: Air-Sea Ammonia Fluxes
Calculated from High-Resolution Summertime Observations Across the Atlantic
Southern Ocean, Geophys. Res. Lett., https://doi.org/10.1029/2020GL091963, 2021.
Amin, S. A., Moffett, J. W., Martens-Habbena, W., Jacquot, J. E., Han, Y.,
Devol, A., Ingalls, A. E., Stahl, D. A., and Armbrust, E. V.: Copper
requirements of the ammonia-oxidizing archaeon Nitrosopumilus maritimus SCM1
and implications for nitrification in the marine environment, Limnol.
Oceanogr., 58, 2037–2045, https://doi.org/10.4319/lo.2013.58.6.2037, 2013.
Armstrong, R. A.: An optimization-based model of iron-light-ammonium
colimitation of nitrate uptake and phytoplankton growth, Limnol. Oceanogr.,
44, 1436–1446, https://doi.org/10.4319/lo.1999.44.6.1436, 1999.
Arrigo, K. R., Dijken, G. L., and Bushinsky, S.: Primary production in the
Southern Ocean, 1997–2006, J. Geophys. Res., 113, C08004,
https://doi.org/10.1029/2007JC004551, 2008.
Atkinson, A., Ward, P., Hunt, B. P. V., Pakhomov, E. A., and Hosie, G. W.:
An overview of Southern Ocean zooplankton data: abundance, biomass, feeding
and functional relationships, CCAMLR Science, 19, 171–218, 2012.
Baer, S. E., Connelly, T. L., Sipler, R. E., Yager, P. L., and Bronk, D. A.:
Effect of temperature on rates of ammonium uptake and nitrification in the
western coastal Arctic during winter, Global Biogeochem. Cy., 28, 1455–1466,
https://doi.org/10.1002/2013GB004765, 2014.
Baird, M. E., Emsley, S. M., and Mcglade, J. M.: Modelling the interacting
effects of nutrient uptake, light capture and temperature on phytoplankton
growth, J. Plankton Res., 23, 829–840,
https://doi.org/10.1093/plankt/23.8.829, 2001.
Bakker, D. C. E., Pfeil, B., Landa, C. S., Metzl, N., O'Brien, K. M., Olsen, A., Smith, K., Cosca, C., Harasawa, S., Jones, S. D., Nakaoka, S., Nojiri, Y., Schuster, U., Steinhoff, T., Sweeney, C., Takahashi, T., Tilbrook, B., Wada, C., Wanninkhof, R., Alin, S. R., Balestrini, C. F., Barbero, L., Bates, N. R., Bianchi, A. A., Bonou, F., Boutin, J., Bozec, Y., Burger, E. F., Cai, W.-J., Castle, R. D., Chen, L., Chierici, M., Currie, K., Evans, W., Featherstone, C., Feely, R. A., Fransson, A., Goyet, C., Greenwood, N., Gregor, L., Hankin, S., Hardman-Mountford, N. J., Harlay, J., Hauck, J., Hoppema, M., Humphreys, M. P., Hunt, C. W., Huss, B., Ibánhez, J. S. P., Johannessen, T., Keeling, R., Kitidis, V., Körtzinger, A., Kozyr, A., Krasakopoulou, E., Kuwata, A., Landschützer, P., Lauvset, S. K., Lefèvre, N., Lo Monaco, C., Manke, A., Mathis, J. T., Merlivat, L., Millero, F. J., Monteiro, P. M. S., Munro, D. R., Murata, A., Newberger, T., Omar, A. M., Ono, T., Paterson, K., Pearce, D., Pierrot, D., Robbins, L. L., Saito, S., Salisbury, J., Schlitzer, R., Schneider, B., Schweitzer, R., Sieger, R., Skjelvan, I., Sullivan, K. F., Sutherland, S. C., Sutton, A. J., Tadokoro, K., Telszewski, M., Tuma, M., van Heuven, S. M. A. C., Vandemark, D., Ward, B., Watson, A. J., and Xu, S.: A multi-decade record of high-quality fCO2 data in version 3 of the Surface Ocean CO2 Atlas (SOCAT), Earth Syst. Sci. Data, 8, 383–413, https://doi.org/10.5194/essd-8-383-2016, 2016.
Bathmann, U. V., Scharek, R., Klaas, C., Dubischar, C. D., and Smetacek, V.:
Spring development of phytoplankton biomass and composition in major water
masses of the Atlantic sector of the Southern Ocean, Deep-Sea Res. Pt. II, 44,
51–67, https://doi.org/10.1016/S0967-0645(96)00063-X, 1997.
Becquevort, S., Menon, P., and Lancelot, C.: Differences of the protozoan
biomass and grazing during spring and summer in the Indian sector of the
Southern Ocean, Polar. Biol., 23, 309–320,
https://doi.org/10.1007/s003000050450, 2000.
Belkin, I. M. and Gordon, A. L.: Southern Ocean fronts from the Greenwich
meridian to Tasmania, J. Geophys. Res.-Oceans, 101, 3675–3696,
https://doi.org/10.1029/95JC02750, 1996.
Bendschneider, K. and Robinson, R. J.: A new spectrophotometric method for
the determination of nitrite in sea water, 1952.
Bianchi, M., Feliatra, F., Tréguer, P., Vincendeau, M. A., and Morvan,
J.: Nitrification rates, ammonium and nitrate distribution in upper layers
of the water column and in sediments of the Indian sector of the Southern
Ocean, Deep-Sea Res. Pt. II, 44, 1017–1032,
https://doi.org/10.1016/S0967-0645(96)00109-9, 1997.
Billen, G.: Heterotrophic utilization and regeneration of nitrogen, in:
Heterotrophic activity in the sea, NATO Conference Series (IV Marine
Sciences), Boston, Massachusetts, United States of America,
https://doi.org/10.1007/978-1-4684-9010-7_15, 1984.
Boyd, P. W., Crossley, A. C., DiTullio, G. R., Griffiths, F. B., Hutchins,
D. A., Queguiner, B., Sedwick, P. N., and Trull, T. W.: Control of
phytoplankton growth by iron supply and irradiance in the subantarctic
Southern Ocean: Experimental results from the SAZ Project, J. Geophys. Res.-Oceans, 106, 31573–31583, https://doi.org/10.1029/2000JC000348, 2001.
Boyd, P. W., Rynearson, T. A., Armstrong, E. A., Fu, F., Hayashi, K., Hu,
Z., Hutchins, D. A., Kudela, R. M., Litchman, E., Mulholland, M. R., Passow,
U., Strzepek, R. F., Whittaker, K. A., Yu, E., and Thomas, M. K.: Marine
Phytoplankton Temperature versus Growth Responses from Polar to Tropical
Waters – Outcome of a Scientific Community-Wide Study, PLoS ONE, 8, 1–17,
https://doi.org/10.1371/journal.pone.0063091, 2013.
Bracher, A. U., Kroon, B. M. A., and Lucas, M. I.: Primary production,
physiological state and composition of phytoplankton in the Atlantic sector
of the Southern Ocean, Mar. Ecol. Prog. Ser., 190, 1–16,
https://doi.org/10.3354/meps190001, 1999.
Broecker, W. S. and Peng, T. H.: Interhemispheric transport of carbon
dioxide by ocean circulation, Nature, 356, 587–589,
https://doi.org/10.1038/356587a0, 1992.
Buongiorno Nardelli, B., Guinehut, S., Verbrugge, N., Cotroneo, Y.,
Zambianchi, E., and Iudicone, D.: Southern Ocean mixed-layer seasonal and
interannual variations from combined satellite and in situ data, J. Geophys. Res.-Oceans, 122, 10042–10060, https://doi.org/10.1002/2017JC013314, 2017.
Campitelli, E.: metR: Tools for Easier Analysis of Meteorological Fields, Zenodo [code], https://doi.org/10.5281/zenodo.2593516, 2019.
Carvalho, F., Kohut, J., Oliver, M. J., and Schofield, O.: Defining the
ecologically relevant mixed-layer depth for Antarctica's coastal seas,
Geophys. Res. Lett., 44, 338–345, https://doi.org/10.1002/2016GL071205, 2017.
Cavagna, A. J., Fripiat, F., Elskens, M., Mangion, P., Chirurgien, L., Closset, I., Lasbleiz, M., Florez-Leiva, L., Cardinal, D., Leblanc, K., Fernandez, C., Lefèvre, D., Oriol, L., Blain, S., Quéguiner, B., and Dehairs, F.: Production regime and associated N cycling in the vicinity of Kerguelen Island, Southern Ocean, Biogeosciences, 12, 6515–6528, https://doi.org/10.5194/bg-12-6515-2015, 2015.
Cavalieri, D. J. and Parkinson, C. L.: Antarctic sea ice variability and
trends, 1979–2006, J. Geophys. Res.-Oceans, 113, C07004,
https://doi.org/10.1029/2007JC004564, 2008.
Cavender-Bares, K. K., Mann, E. L., Chisholm, S. W., Ondrusek, M. E., and
Bidigare, R. R.: Differential response of equatorial Pacific phytoplankton
to iron fertilization, Limnol. Oceanogr., 44, 237–246,
https://doi.org/10.4319/lo.1999.44.2.0237, 1999.
Checkley Jr., D. M. and Miller, C. A.: Nitrogen isotope fractionation by
oceanic zooplankton, Deep-Sea Res., 36, 1449–1456,
https://doi.org/10.1016/0198-0149(89)90050-2, 1989.
Church, M. J., DeLong, E. F., Ducklow, H. W., Karner, M. B., Preston, C. M.,
and Karl, D. M.: Abundance and distribution of planktonic Archaea and
Bacteria in the waters west of the Antarctic Peninsula, Limnol. Oceanogr., 48,
1893–1902, https://doi.org/10.4319/lo.2003.48.5.1893, 2003.
Coale, K. H., Gordon, R. M., and Wang, X.: The distribution and behaviour of
dissolved and particulate iron and zinc in the Ross Sea and Antarctic
circumpolar current along 170∘W, Deep-Sea Res. Pt. I, 52, 295–318,
https://doi.org/10.1016/j.dsr.2004.09.008, 2005.
Cochlan, W. P.: Seasonal study of uptake and regeneration of nitrogen on the
Scotian Shelf, Cont. Shelf. Res., 5, 555–577,
https://doi.org/10.1016/0278-4343(86)90076-2, 1986.
Cochlan, W. P.: Nitrogen uptake in the Southern Ocean, in: Nitrogen in the
Marine Environment, edited by: Capone, D. G., Bronk, D. A., Mulholland, M.
R., and Carpenter, E. J., Academic Press, Elsevier, 569–596,
https://doi.org/10.1016/B978-0-12-372522-6.00012-8, 2008.
Cochlan, W. P., Bronk, D. A., and Coale, K. H.: Trace metals and nitrogenous
nutrition of Antarctic phytoplankton: experimental observations in the Ross
Sea, Deep-Sea Res. Pt. II., 49, 3365–3390,
https://doi.org/10.1016/S0967-0645(02)00088-7, 2002.
Coello-Camba, A. and Agustí, S.: Thermal thresholds of phytoplankton
growth in polar waters and their consequences for a warming polar ocean,
Front. Mar. Sci., 4, 168,
https://doi.org/10.3389/fmars.2017.00168, 2017.
Cota, G. F., Smith, W. O., Nelson, D. M., Muench, R. D., and Gordon, L. I.:
Nutrient and biogenic particulate distributions, primary productivity and
nitrogen uptake in the Weddell-Scotia Sea marginal ice zone during winter, J.
Mar. Res., 50, 155–181, https://doi.org/10.1357/002224092784797764, 1992.
Daly, K. L., Smith, W. O., Johnson, G. C., DiTullio, G. R., Jones, D. R.,
Mordy, C. W., Feely, R. A., Hansell, D. A., and Zhang, J.-Z.: Hydrography,
nutrients, and carbon pools in the Pacific sector of the Southern Ocean:
Implications for carbon flux, J. Geophys. Res.-Oceans, 106, 7107–7124,
https://doi.org/10.1029/1999JC000090, 2001.
Deary, A.: A high-resolution study of the early- to late summer progression
in primary production and carbon export potential in the Atlantic Southern
Ocean, Honours thesis, University of Cape Town, South Africa, https://doi.org/10.5281/zenodo.5865488, 2020.
Dennett, M. R., Mathot, S., Caron, D. A., Smith, W. O., and Lonsdale, D. J.:
Abundance and distribution of phototrophic and heterotrophic nano- and
microplankton in the southern Ross Sea, Deep-Sea Res. Pt. II, 48, 4019–4037,
https://doi.org/10.1016/S0967-0645(01)00079-0, 2001.
Deppeler, S. L. and Davidson, A. T.: Southern Ocean phytoplankton in a
changing climate, Front. Mar. Sci., 4, 40,
https://doi.org/10.3389/fmars.2017.00040, 2017.
Detmer, A. E. and Bathmann, U. V.: Distribution patterns of autotrophic
pico-and nanoplankton and their relative contribution to algal biomass
during spring in the Atlantic sector of the Southern Ocean, Deep-Sea Res. Pt. II, 44, 299–320, https://doi.org/10.1016/S0967-0645(96)00068-9, 1997.
Dong, S., Sprintall, J., Gille, S. T., and Talley, L.: Southern Ocean
mixed-layer depth from Argo float profiles, J. Geophys. Res.-Oceans, 113, C06013,
https://doi.org/10.1029/2006JC004051, 2008.
Dortch, Q.: The interaction between ammonium and nitrate uptake in
phytoplankton, Mar. Ecol. Prog. Ser., 61, 183–201,
https://doi.org/10.3354/meps061183, 1990.
Dugdale, R. C. and Goering, J. J.: Uptake of new and regenerated forms of
nitrogen in primary productivity, Limnol. Oceanogr., 12, 196–206,
https://doi.org/10.4319/lo.1967.12.2.0196, 1967.
Dugdale, R. C. and Wilkerson, F. P.: The use of 15N to measure nitrogen
uptake in eutrophic oceans, experimental considerations 1, 2, Limnol. Oceanogr., 31, 673–689, https://doi.org/10.4319/lo.1986.31.4.0673, 1986.
Ellwood, M. J., Boyd, P. W., and Sutton, P.: Winter-time dissolved iron and
nutrient distributions in the Subantarctic Zone from 40–52∘S; 155–160∘E,
Geophys. Res. Lett., 35, https://doi.org/10.1029/2008GL033699, 2008.
Eppley, R. W. and Peterson, B. J.: Particulate organic matter flux and
planktonic new production in the deep ocean, Nature, 282, 677–680,
https://doi.org/10.1038/282677a0, 1979.
Fawcett, S. E. and Ward, B. B.: Phytoplankton succession and nitrogen
utilization during the development of an upwelling bloom, Mar. Ecol. Prog. Ser.,
428, 13–31, https://doi.org/10.3354/meps09070, 2011.
Fawcett, S. E., Lomas, M. W., Casey, J. R., Ward, B. B., and Sigman, D. M.:
Assimilation of upwelled nitrate by small eukaryotes in the Sargasso Sea,
Nat. Geosci., 4, 717–722, https://doi.org/10.1038/ngeo1265, 2011.
Fawcett, S. E., Lomas, M. W., Ward, B. B., and Sigman, D. M.: The
counterintuitive effect of summer-to-fall mixed layer deepening on
eukaryotic new production in the Sargasso Sea, Global Biogeochem. Cy., 28,
86–102, https://doi.org/10.1002/2013GB004579, 2014.
Fiala, M. and Oriol, L.: Light-temperature interactions on the growth of
Antarctic diatoms, Polar. Biol., 10, 629–636,
https://doi.org/10.1007/BF00239374, 1990.
Fiala, M., Semeneh, M., and Oriol, L.: Size-fractionated phytoplankton
biomass and species composition in the Indian sector of the Southern Ocean
during austral summer, J. Mar. Syst., 17, 179–194,
https://doi.org/10.1016/S0924-7963(98)00037-2, 1998.
Finkel, Z. V., Irwin, A. J., and Schofield, O.: Resource limitation alters
the 3/4 size scaling of metabolic rates in phytoplankton, Mar. Ecol. Prog. Ser.,
273, 269–279, https://doi.org/10.3354/meps273269, 2004.
Finley, A., Banerjee, S., and Hjelle, Ø.: MBA: Multilevel B-Spline Approximation, https://CRAN.R-project.org/package=MBA, 2017.
Forsythe, W. C., Rykiel Jr., E. J., Stahl, R. S., Wu, H. I., and Schoolfield,
R. M.: A model comparison for daylength as a function of latitude and day of
year, Ecol. Model., 80, 87–95, https://doi.org/10.1016/0304-3800(94)00034-F,
1995.
Franck, V. M., Smith, G. J., Bruland, K. W., and Brzezinski, M. A.:
Comparison of size-dependent carbon, nitrate, and silicic acid uptake rates
in high-and low-iron waters, Limnol. Oceanogr., 50, 825–838,
https://doi.org/10.4319/lo.2005.50.3.0825, 2005.
Francois, R., Altabet, M. A., and Burckle, L. H.: Glacial to interglacial
changes in surface nitrate utilization in the Indian sector of the Southern
Ocean as recorded by sediment δ15N, Paleoceanography, 7, 589–606,
https://doi.org/10.1029/92PA01573, 1992.
Fripiat, F., Elskens, M., Trull, T.W., Blain, S., Cavagna, A.J., Fernandez,
C., Fonseca-Batista, D., Planchon, F., Raimbault, P., Roukaerts, A. and
Dehairs, F.: Significant mixed layer nitrification in a natural
iron-fertilized bloom of the Southern Ocean, Global Biogeochem. Cy., 29,
1929–1943, https://doi.org/10.1002/2014GB005051, 2015.
Fripiat, F., Martínez-García, A., Fawcett, S. E., Kemeny, P. C.,
Studer, A. S., Smart, S. M., Rubach, F., Oleynik, S., Sigman, D. M., and
Haug, G. H.: The isotope effect of nitrate assimilation in the Antarctic
Zone: Improved estimates and paleoceanographic implications, Geochim.
Cosmochim. Ac., 247, 261–279, https://doi.org/10.1016/j.gca.2018.12.003,
2019.
Fripiat, F., Martínez-García, A., Marconi, D., Fawcett, S. E.,
Kopf, S., Luu, V., Rafter, P., Zhang, R., Sigman, D., and Haug, G.: Nitrogen
isotopic constraints on nutrient transport to the upper ocean, Nat. Geosci., 14, 855–861, https://doi.org/10.1038/s41561-021-00836-8, 2021.
Frölicher, T. L., Sarmiento, J. L., Paynter, D. J., Dunne, J. P.,
Krasting, J. P., and Winton, M.: Dominance of the Southern Ocean in
anthropogenic carbon and heat uptake in CMIP5 models, J. Climate, 28,
862–886, https://doi.org/10.1175/JCLI-D-14-00117.1, 2015.
Froneman, P. W., Ansorge, I. J., Pakhomov, E. A., and Lutjeharms, J. R. E.:
Plankton community structure in the physical environment surrounding the
Prince Edward Islands (Southern Ocean), Polar. Biol., 22, 145–155,
https://doi.org/10.1007/s003000050404, 1999.
Fujiki, T. and Taguchi, S.: Variability in chlorophyll a specific absorption
coefficient in marine phytoplankton as a function of cell size and
irradiance, J. Plankton Res., 24, 859–874,
https://doi.org/10.1093/plankt/24.9.859, 2002.
Gasol, J. M. and Giorgio, P. A.: Using flow cytometry for counting natural
planktonic bacteria and understanding the structure of planktonic bacterial
communities, Sci. Mar., 64, 197–224,
https://doi.org/10.3989/scimar.2000.64n2197, 2000.
Gibson, J. A. and Trull, T. W.: Annual cycle of fCO2 under sea-ice and in
open water in Prydz Bay, East Antarctica, Mar. Chem., 66, 187–200,
https://doi.org/10.1016/S0304-4203(99)00040-7, 1999.
Glibert, P. M.: Regional studies of daily, seasonal and size fraction
variability in ammonium remineralization, Mar. Biol., 70, 209–222,
https://doi.org/10.1007/BF00397687, 1982.
Goeyens, L., Tréguer, P., Lancelot, C., Mathot, S., Becquevort, S.,
Morvan, J., Dehairs, F., and Baeyens, W.: Ammonium regeneration in the
Scotia-Weddell Confluence area during spring 1988, Mar. Ecol. Prog. Ser.,
345–361, https://doi.org/10.3354/meps078241, 1991.
Goeyens, L., Tréguer, P., Baumann, M. E. M., Baeyens, W., and Dehairs,
F.: The leading role of ammonium in the nitrogen uptake regime of Southern
Ocean marginal ice zones, J. Mar. Syst., 6, 345–361,
https://doi.org/10.1016/0924-7963(94)00033-8, 1995.
Granger, J., Sigman, D. M., Needoba, J. A., and Harrison, P. J.: Coupled
nitrogen and oxygen isotope fractionation of nitrate during assimilation by
cultures of marine phytoplankton, Limnol. Oceanogr., 49, 1763–1773,
https://doi.org/10.4319/lo.2004.49.5.1763, 2004.
Granger, J., Sigman, D. M., Rohde, M. M., Maldonado, M. T., and Tortell, P.
D.: N and O isotope effects during nitrate assimilation by unicellular
prokaryotic and eukaryotic plankton cultures, Geochim. Cosmochim. Ac., 74,
1030–1040, https://doi.org/10.1016/j.gca.2009.10.044, 2010.
Gray, A. R., Johnson, K. S., Bushinsky, S. M., Riser, S. C., Russell, J. L.,
Talley, L. D., Wanninkhof, R., Williams, N. L., and Sarmiento, J. L.:
Autonomous biogeochemical floats detect significant carbon dioxide
outgassing in the high-latitude Southern Ocean, Geophys. Res. Lett., 45,
9049–9057, https://doi.org/10.1029/2018GL078013, 2018.
Grolemund, G. and Wickham, H.: Dates and Times Made Easy with lubridate, J. Stat. Softw., 40, 1–25, https://www.jstatsoft.org/v40/i03/, 2011.
Hasle, R. G.: The inverted microscope method, in: Phytoplankton manual,
88–96, 1978.
Hauck, J., Völker, C., Wolf-Gladrow, D. A., Laufkötter, C., Vogt,
M., Aumont, O., Bopp, L., Buitenhuis, E. T., Doney, S. C., Dunne, J., and
Gruber, N.: On the Southern Ocean CO2 uptake and the role of the biological
carbon pump in the 21st century, Global Biogeochem. Cy., 29, 1451–1470,
https://doi.org/10.1002/2015GB005140, 2015.
Henley, S. F., Tuerena, R. E., Annett, A. L., Fallick, A. E., Meredith, M.
P., Venables, H. J., Clarke, A., and Ganeshram, R. S.: Macronutrient supply,
uptake and recycling in the coastal ocean of the west Antarctic Peninsula,
Deep-Sea Res. Pt. II, 139, 58–76, https://doi.org/10.1016/j.dsr2.2016.10.003,
2017.
Henley, S. F., Cavan, E. L., Fawcett, S. E., Kerr, R., Monteiro, T.,
Sherrell, R. M., Bowie, A. R., Boyd, P. W., Barnes, D. K., Schloss, I. R.,
Marshall, T., Flynn, R., and Smith, S.: Changing biogeochemistry of the
Southern Ocean and its ecosystem implications, Front. Mar. Sci.,
7, 581, https://doi.org/10.3389/fmars.2020.00581, 2020.
Herbert, R. A.: Nitrogen cycling in coastal marine ecosystems, FEMS
Microbiol. Rev., 23, 563–590,
https://doi.org/10.1111/j.1574-6976.1999.tb00414.x, 1999.
Hewes, C. D., Holm-Hansen, O., and Sakshaug, E.: Alternate carbon pathways
at lower trophic levels in the Antarctic food web, in: Antarctic nutrient
cycles and food webs, edited by: Siegfried, W. R., Condy, P. R., Laws, R. M.,
Springer, Berlin, Heidelberg, 277–283,
https://doi.org/10.1007/978-3-642-82275-9_40, 1985.
Hewes, C. D., Sakshaug, E., Reid, F. M., and Holm-Hansen, O.: Microbial
autotrophic and heterotrophic eucaryotes in Antarctic waters: relationships
between biomass and chlorophyll, adenosine triphosphate and particulate
organic carbon, Mar. Ecol. Prog. Ser., 63, 27–36, 1990.
Hiscock, M. R., Marra, J., Smith Jr., W. O., Goericke, R., Measures, C., Vink,
S., Olson, R. J., Sosik, H. M., and Barber, R. T.: Primary productivity and its
regulation in the Pacific Sector of the Southern Ocean, Deep-Sea Res. Pt. II,
50, 533–558, https://doi.org/10.1016/S0967-0645(02)00583-0, 2003.
Holmes, R. M., Aminot, A., Kérouel, R., Hooker, B. A., and Peterson, B.
J.: A simple and precise method for measuring ammonium in marine and
freshwater ecosystems, Can. J. Fish. Aquat. Sci., 56, 1801–1808,
https://doi.org/10.1139/f99-128, 1999.
Honjo, S., Francois, R., Manganini, S., Dymond, J., and Collier, R.:
Particle fluxes to the interior of the Southern Ocean in the Western Pacific
sector along 170 W, Deep-Sea Res. Pt. II, 47, 3521–3548,
https://doi.org/10.1016/S0967-0645(00)00077-1, 2000.
Hooper, A. B. and Terry, K. R.: Photoinactivation of ammonia oxidation in
Nitrosomonas, J. Bacteriol., 119, 899–906,
https://doi.org/10.1128/jb.119.3.899-906.1974, 1974.
Horak, R. E., Qin, W., Schauer, A. J., Armbrust, E. V., Ingalls, A. E.,
Moffett, J. W., Stahl, D. A., and Devol, A. H.: Ammonia oxidation kinetics
and temperature sensitivity of a natural marine community dominated by
Archaea, ISME J., 7, 2023–2033, https://doi.org/10.1038/ismej.2013.75, 2013.
Horrigan, S. G. and Springer, A. L.: Oceanic and estuarine ammonium
oxidation: Effects of light, Limnol. Oceanogr., 35, 479–482,
https://doi.org/10.4319/lo.1990.35.2.0479, 1990.
Hudson, R. J. and Morel, F. M.: Trace metal transport by marine
microorganisms: implications of metal coordination kinetics, Deep-Sea Res. Pt. I, 40, 129–150, https://doi.org/10.1016/0967-0637(93)90057-A, 1993.
Iida, T. and Odate, T.: Seasonal variability of phytoplankton biomass and
composition in the major water masses of the Indian Ocean sector of the
Southern Ocean, Polar. Sci., 8, 283–297,
https://doi.org/10.1016/j.polar.2014.03.003, 2014.
Ishikawa, A., Wright, S. W., Enden, R., Davidson, A. T., and Marchant, H.
J.: Abundance, size structure and community composition of phytoplankton in
the Southern Ocean in the austral summer 1999/2000, Polar Biogeosci.,
15, 11–26, https://doi.org/10.15094/00006180, 2002.
Janssen, D. J., Sieber, M., Ellwood, M. J., Conway, T. M., Barrett, P. M.,
Chen, X., Souza, G. F., Hassler, C. S., and Jaccard, S. L.: Trace metal and
nutrient dynamics across broad biogeochemical gradients in the Indian and
Pacific sectors of the Southern Ocean, Mar. Chem., 221, 103773,
https://doi.org/10.1016/j.marchem.2020.103773, 2020.
Jeong, H. J. and Latz, M. I.: Growth and grazing rates of the heterotrophic
dinoflagellates Protoperidinium spp. on red tide dinoflagellates, Mar. Ecol. Prog. Ser., 106, 173–173, https://doi.org/10.3354/meps106173, 1994.
Jiang, H. B., Fu, F. X., Rivero-Calle, S., Levine, N. M.,
Sañudo-Wilhelmy, S. A., Qu, P. P., Wang, X. W., Pinedo-Gonzalez, P.,
Zhu, Z., and Hutchins, D. A.: Ocean warming alleviates iron limitation of
marine nitrogen fixation, Nat. Clim. Change, 8, 709–712,
https://doi.org/10.1038/s41558-018-0216-8, 2018.
Johnson, K. S., Plant, J. N., Dunne, J. P., Talley, L. D., and Sarmiento, J.
L.: Annual nitrate drawdown observed by SOCCOM profiling floats and the
relationship to annual net community production, J. Geophys. Res.-Oceans, 122,
6668–6683, https://doi.org/10.1002/2017JC012839, 2017.
Joubert, W. R., Thomalla, S. J., Waldron, H. N., Lucas, M. I., Boye, M., Le Moigne, F. A. C., Planchon, F., and Speich, S.: Nitrogen uptake by phytoplankton in the Atlantic sector of the Southern Ocean during late austral summer, Biogeosciences, 8, 2947–2959, https://doi.org/10.5194/bg-8-2947-2011, 2011.
Kassambara, A.: ggpubr: “ggplot2” Based Publication Ready Plots, https://CRAN.R-project.org/package=ggpubr, 2019.
Kattner, G., Thomas, D. N., Haas, C., Kennedy, H., and Dieckmann, G. S.:
Surface ice and gap layers in Antarctic sea ice: highly productive habitats,
Mar. Ecol. Prog. Ser., 277, 1–12, https://doi.org/10.3354/meps277001, 2004.
Kelley, D. and Richards, C.: oce: Analysis of Oceanographic Data, R package version 1.5-0, https://dankelley.github.io/oce/, 2022.
Kirchman, D. L.: The Uptake of Inorganic Nutrients by Heterotrophic
Bacteria, Microb. Ecol., 28, 255–271, https://doi.org/10.1007/BF00166816,
1994.
Kitzinger, K., Padilla, C. C., Marchant, H. K., Hach, P. F., Herbold, C. W.,
Kidane, A. T., Könneke, M., Littmann, S., Mooshammer, M., Niggemann, J.,
and Petrov, S.: Cyanate and urea are substrates for nitrification by
Thaumarchaeota in the marine environment, Nat. Microbiol., 4, 234–243,
https://doi.org/10.1038/s41564-018-0316-2, 2019.
Klawonn, I., Bonaglia, S., Whitehouse, M. J., Littmann, S., Tienken, D.,
Kuypers, M. M., Brüchert, V., and Ploug, H.: Untangling hidden nutrient
dynamics: rapid ammonium cycling and single-cell ammonium assimilation in
marine plankton communities, ISME J., 13, 1960–1974,
https://doi.org/10.1038/s41396-019-0386-z, 2019.
Knapp, A. N., Dekaezemacker, J., Bonnet, S., Sohm, J. A., and Capone, D. G.:
Sensitivity of Trichodesmium erythraeum and Crocosphaera watsonii abundance
and N2 fixation rates to varying NO
Kobayashi, F. and Takahashi, K.: Distribution of diatoms along the
equatorial transect in the western and central Pacific during the 1999 La
Niña conditions, Deep-Sea Res. Pt. II, 49, 2801–2821,
https://doi.org/10.1016/S0967-0645(02)00059-0, 2002.
Koike, I., Holm-Hansen, O., and Biggs, D. C.: Phytoplankton With Special
Reference To Ammonium Cycling, Mar. Ecol., 30, 105–116,
https://doi.org/10.3354/meps030105, 1986.
Kopczyńska, E. E., Savoye, N., Dehairs, F., Cardinal, D., and Elskens,
M.: Spring phytoplankton assemblages in the Southern Ocean between Australia
and Antarctica, Polar. Biol., 31, 77–88,
https://doi.org/10.1007/s00300-007-0335-6, 2007.
Kottmeier, S. T. and Sullivan, C. W.: Late winter primary production and
bacterial production in sea ice and seawater west of the Antarctic
Peninsula, Mar. Ecol. Prog. Ser., 36, 287–298,
https://doi.org/10.3354/meps036287, 1987.
Kustka, A. B., Sañudo-Wilhelmy, S. A., Carpenter, E. J., Capone, D., Burns,
J., and Sunda, W. G.: Iron requirements for dinitrogen-and ammonium-supported
growth in cultures of Trichodesmium (IMS 101): Comparison with nitrogen
fixation rates and iron: Carbon ratios of field populations, Limnol. Oceanogr., 48, 1869–1884, https://doi.org/10.4319/lo.2003.48.5.1869, 2003.
La Roche, J.: Ammonium regeneration: its contribution to phytoplankton
nitrogen requirements in a eutrophic environment, Mar. Biol., 75, 231–240,
https://doi.org/10.1007/BF00406007, 1983.
Lauderdale, J. M., Garabato, A. C. N., Oliver, K. I., Follows, M. J., and
Williams, R. G.: Wind-driven changes in Southern Ocean residual circulation,
ocean carbon reservoirs and atmospheric CO2, Clim. Dynam., 41, 2145–2164,
https://doi.org/10.1007/s00382-012-1650-3, 2013.
Le Moigne, F. A. C., Boye, M., Masson, A., Corvaisier, R., Grossteffan, E., Guéneugues, A., and Pondaven, P.: Description of the biogeochemical features of the subtropical southeastern Atlantic and the Southern Ocean south of South Africa during the austral summer of the International Polar Year, Biogeosciences, 10, 281–295, https://doi.org/10.5194/bg-10-281-2013, 2013.
Lee, S. H., Joo, H. M., Liu, Z., Chen, J., and He, J.: Phytoplankton
productivity in newly opened waters of the Western Arctic Ocean, Deep-Sea Res. Pt. II, 81, 18–27, https://doi.org/10.1016/j.dsr2.2011.06.005, 2012.
Lee, S. H., Yun, M. S., Kim, B. K., Joo, H., Kang, S. H., Kang, C. K., and
Whitledge, T. E.: Contribution of small phytoplankton to total primary
production in the Chukchi Sea, Cont. Shelf. Res., 68, 43–50,
https://doi.org/10.1016/j.csr.2013.08.008, 2013.
Legrand, M., Ducroz, F., Wagenbach, D., Mulvaney, R., and Hall, J.: Ammonium
in coastal Antarctic aerosol and snow: Role of polar ocean and penguin
emissions, J. Geophys. Res.-Atmos., 103, 11043–11056,
https://doi.org/10.1029/97JD01976, 1998.
Lehette, P., Tovar-Sánchez, A., Duarte, C. M., and Hernández-León,
S.: Krill excretion and its effect on primary production, Mar. Ecol. Prog. Ser.,
459, 29–38, https://doi.org/10.3354/meps09746, 2012.
Lipschultz, F.: Isotope tracer methods for studies of the marine nitrogen
cycle, in: Nitrogen in the Marine Environment, 2nd ed., edited by: Capone,
D. G., Bronk, D. A., Mulholland, M. R., and Carpenter, E. J., Academic Press,
Burlington, Massachusetts, United States of America,
https://doi.org/10.1016/B978-0-12-372522-6.00031-1, 2008.
Llort, J., Lévy, M., Sallée, J. B., and Tagliabue, A.: Nonmonotonic
response of primary production and export to changes in mixed-layer depth in
the Southern Ocean, Geophys. Res. Lett., 46, 3368–3377,
https://doi.org/10.1029/2018GL081788, 2019.
Lourey, M. J., Trull, T. W., and Sigman, D. M.: Sensitivity of δ 15
N of nitrate, surface suspended and deep sinking particulate nitrogen to
seasonal nitrate depletion in the Southern Ocean, Global Biogeochem. Cy., 17, 1081,
https://doi.org/10.1029/2002GB001973, 2003.
Lu, S., Liu, X., Liu, C., Cheng, G., and Shen, H.: Influence of
photoinhibition on nitrification by ammonia-oxidizing microorganisms in
aquatic ecosystems, Rev. Environ. Sci. Bio., 19, 531–542,
https://doi.org/10.1007/s11157-020-09540-2, 2020.
Lutjeharms, J. R. E. and Valentine, H. R.: Southern ocean thermal fronts
south of Africa, Deep-Sea Res., 31, 1461–1475,
https://doi.org/10.1016/0198-0149(84)90082-7, 1984.
Macko, S. A., Estep, M. L. F., Engel, M. H., and Hare, P. E.: Kinetic
fractionation of stable nitrogen isotopes during amino acid transamination,
Geochim. Cosmochim. Ac., 50, 2143–2146,
https://doi.org/10.1016/0016-7037(86)90068-2, 1986.
Maldonado, M. T., Allen, A. E., Chong, J. S., Lin, K., Leus, D., Karpenko,
N., and Harris, S. L.: Copper-dependent iron transport in coastal and
oceanic diatoms, Limnol. Oceanogr., 51, 1729–1743,
https://doi.org/10.4319/lo.2006.51.4.1729, 2006.
Marie, D., Partensky, F., Jacquet, S., and Vaulot, D.: Enumeration and cell
cycle analysis of natural populations of marine picoplankton by flow
cytometry using the nucleic acid stain SYBR Green I, Appl. Environ. Microb.,
63, 186–193, https://doi.org/10.1128/aem.63.1.186-193.1997, 1997.
Marie, D., Simon, N., and Vaulot, D.: Phytoplankton cell counting by flow
cytometry, Algal Culturing Techniques, 1, 253–267,
https://doi.org/10.1016/B978-012088426-1/50018-4, 2005.
Martin, J. H., Fitzwater, S. E., and Gordon, R. M.: Iron deficiency limits
phytoplankton growth in Antarctic waters, Global Biogeochem. Cy., 4, 5–12,
https://doi.org/10.1029/GB004i001p00005, 1990.
Mayzaud, P., Razouls, S., Errhif, A., Tirelli, V., and Labat, J. P.:
Feeding, respiration and egg production rates of copepods during austral
spring in the Indian sector of the Antarctic Ocean: role of the zooplankton
community in carbon transformation, Deep-Sea Res. Pt. I, 49, 1027–1048,
https://doi.org/10.1016/S0967-0637(02)00012-2, 2002.
McIlvin, M. R. and Altabet, M. A.: Chemical conversion of nitrate and
nitrite to nitrous oxide for nitrogen and oxygen isotopic analysis in
freshwater and seawater, Anal. Chem., 77, 5589–5595,
https://doi.org/10.1021/ac050528s, 2005.
McIlvin, M. R. and Casciotti, K. L.: Technical updates to the bacterial
method for nitrate isotopic analyses, Anal. Chem., 83, 1850–1856,
https://doi.org/10.1021/ac1028984, 2011.
Mdutyana, M.: Mixed layer nitrogen cycling in the Southern Ocean:
seasonality, kinetics, and biogeochemical implications, Ph.D. dissertation,
University of Cape Town, South Africa, https://doi.org/10.5281/zenodo.5865349, 2021.
Mdutyana, M., Thomalla, S. J., Philibert, R., Ward, B. B., and Fawcett, S.
E.: The seasonal cycle of nitrogen uptake and nitrification in the Atlantic
sector of the Southern Ocean, Global Biogeochem. Cy., 34, 006363,
https://doi.org/10.1029/2019GB006363, 2020.
Mei, Z. P., Finkel, Z. V., and Irwin, A. J.: Light and nutrient availability
affect the size-scaling of growth in phytoplankton, J. Theor. Biol., 259,
582–588, https://doi.org/10.1016/j.jtbi.2009.04.018, 2009.
Mengesha, S., Dehairs, F., Fiala, M., Elskens, M., and Goeyens, L.: Seasonal
variation of phytoplankton community structure and nitrogen uptake regime in
the Indian Sector of the Southern Ocean, Polar. Biol., 20, 259–272,
https://doi.org/10.1007/s003000050302, 1998.
Möbius, J.: Isotope fractionation during nitrogen remineralization
(ammonification): Implications for nitrogen isotope biogeochemistry, Geochim.
Cosmochim. Ac., 105, 422–432, https://doi.org/10.1016/j.gca.2012.11.048,
2013.
Mongwe, N. P., Vichi, M., and Monteiro, P. M. S.: The seasonal cycle of pCO2 and CO2 fluxes in the Southern Ocean: diagnosing anomalies in CMIP5 Earth system models, Biogeosciences, 15, 2851–2872, https://doi.org/10.5194/bg-15-2851-2018, 2018.
Mordy, C. W., Penny, D. M., and Sullivan, C. W.: Spatial distribution of
bacterioplankton biomass and production in the marginal ice-edge zone of the
Weddell-Scotia Sea during austral winter, Mar. Ecol. Prog. Ser., 122, 9–19,
https://doi.org/10.3354/meps122009, 1995.
Morel, F. M., Hudson, R. J., and Price, N. M.: Limitation of productivity by
trace metals in the sea, Limnol. Oceanogr., 36, 1742–1755,
https://doi.org/10.4319/lo.1991.36.8.1742, 1991.
Mtshali, T. N., Horsten, N. R., Thomalla, S. J., Ryan-Keogh, T. J.,
Nicholson, S. A., Roychoudhury, A. N., Bucciarelli, E., Sarthou, G.,
Tagliabue, A., and Monteiro, P. M.: Seasonal depletion of the dissolved iron
reservoirs in the sub-Antarctic zone of the Southern Atlantic Ocean, Geophys. Res. Lett., 46, 4386–4395, https://doi.org/10.1029/2018GL081355, 2019.
Murphy, J. and Riley, J. P.: A modified single solution method for the
determination of phosphate in natural waters, Anal. Chim. Acta, 27, 31–36,
https://doi.org/10.1016/S0003-2670(00)88444-5, 1962.
Nelson, D. M., Brzezinski, M. A., Sigmon, D. E., and Franck, V. M.: A
seasonal progression of Si limitation in the Pacific sector of the Southern
Ocean, Deep-Sea Res. Pt. II, 48, 3973–3995,
https://doi.org/10.1016/S0967-0645(01)00076-5, 2001.
Nicholson, S. A., Lévy, M., Jouanno, J., Capet, X., Swart, S., and
Monteiro, P. M.: Iron supply pathways between the surface and subsurface
waters of the Southern Ocean: from winter entrainment to summer storms,
Geophys. Res. Lett., 46, 14567–14575, https://doi.org/10.1029/2019GL084657,
2019.
Olson, R. J.: Differential photoinhibition of marine nitrifying bacteria: a
possible mechanism for the formation of the primary nitrite maximum, J. Mar.
Res., 39, 227–238, 1981.
Orsi, A. H., Whitworth, T., and Nowlin, W. D.: On the meridional extent and
fronts of the Antarctic Circumpolar Current, Deep-Sea Res. Pt. I, 42,
641–673, https://doi.org/10.1016/0967-0637(95)00021-W, 1995.
Painter, S. C., Patey, M. D., Tarran, G. A., and Torres-Valdés, S.:
Picoeukaryote distribution in relation to nitrate uptake in the oceanic
nitracline, Aquat. Microb. Ecol., 72, 195–213,
https://doi.org/10.3354/ame01695, 2014.
Paulot, F., Jacob, D. J., Johnson, M. T., Bell, T. G., Baker, A. R., Keene,
W. C., Lima, I. D., Doney, S. C., and Stock, C. A.: Global oceanic emission
of ammonia: Constraints from seawater and atmospheric observations, Global Biogeochem. Cy., 29, 1165–1178, https://doi.org/10.1002/2015GB005106, 2015.
Pausch, F., Bischof, K., and Trimborn, S.: Iron and manganese co-limit
growth of the Southern Ocean diatom Chaetoceros debilis, PLoS ONE, 14,
0221959, https://doi.org/10.1371/journal.pone.0221959, 2019.
Pearce, I., Davidson, A. T., Thomson, P. G., Wright, S., and Enden, R.:
Marine microbial ecology off East Antarctica (30–80∘ E): Rates
of bacterial and phytoplankton growth and grazing by heterotrophic protists,
Deep-Sea Res. Pt. II, 57, 849–862,
https://doi.org/10.1016/j.dsr2.2008.04.039, 2010.
Peng, X., Fuchsman, C. A., Jayakumar, A., Oleynik, S., Martens-Habbena, W.,
Devol, A. H., and Ward, B. B.: Ammonia and nitrite oxidation in the Eastern
Tropical North Pacific, Global Biogeochem. Cy., 29, 2034–2049,
https://doi.org/10.1002/2015GB005278, 2015.
Philibert, R., Waldron, H., and Clark, D.: A geographical and seasonal
comparison of nitrogen uptake by phytoplankton in the Southern Ocean, Ocean
Sci., 11, 251–267, https://doi.org/10.5194/os-11-251-2015, 2015.
Plate, T. and Heiberger, R.: abind: Combine multi-dimensional arrays v1.1, https://CRAN.R-project.org/package=abind, 2019.
Pomeroy, L. R. and Wiebe, W. J.: Temperature and substrates as interactive
limiting factors for marine heterotrophic bacteria, Aquat. Microb. Ecol., 23,
187–204, https://doi.org/10.3354/ame023187, 2001.
Prézelin, B. B., Hofmann, E. E., Mengelt, C., and Klinck, J. M.: The
linkage between Upper Circumpolar Deep Water (UCDW) and phytoplankton
assemblages on the west Antarctic Peninsula continental shelf, J. Mar. Res.,
58, 165–202, https://doi.org/10.1357/002224000321511133, 2000.
Price, N. M., Ahner, B. A., and Morel, F. M.: The equatorial Pacific Ocean:
Grazer-controlled phytoplankton populations in an iron-limited ecosystem 1,
Limnol. Oceanogr., 39, 520–534, https://doi.org/10.4319/lo.1994.39.3.0520,
1994.
Priddle, J., Nedwell, D. B., Whitehouse, M. J., Reay, D. S., Savidge, G.,
Gilpin, L. C., Murphy, E. J., and Ellis-Evans, J. C.: Re-examining the
Antarctic Paradox: speculation on the Southern Ocean as a nutrient-limited
system, Ann. Glaciol., 27, 661–668,
https://doi.org/10.3189/1998AoG27-1-661-668, 1998.
Primeau, F. W., Holzer, M., and DeVries, T.: Southern Ocean nutrient
trapping and the efficiency of the biological pump, J. Geophys. Res.-Oceans,
118, 2547–2564, https://doi.org/10.1002/jgrc.20181, 2013.
R Core Team: R: A language and environment for statistical computing, https://www.R-project.org/, 2020.
Raven, J. A.: The iron and molybdenum use efficiencies of plant growth with
different energy, carbon and nitrogen sources, New Phytol., 109, 279–287,
https://doi.org/10.1111/j.1469-8137.1988.tb04196.x, 1988.
Reay, D. S., Priddle, J., Nedwell, D. B., Whitehouse, M. J., Ellis-Evans, J.
C., Deubert, C., and Connelly, D. P.: Regulation by low temperature of
phytoplankton growth and nutrient uptake in the Southern Ocean, Mar. Ecol. Prog. Ser., 219, 51–64, https://doi.org/10.3354/meps219051, 2001.
Rembauville, M., Briggs, N., Ardyna, M., Uitz, J., Catala, P., Penkerc'h,
C., Poteau, A., Claustre, H., and Blain, S.: Plankton assemblage estimated
with BGC-Argo floats in the Southern Ocean: Implications for seasonal
successions and particle export, J. Geophys. Res.-Oceans, 122, 8278–8292,
https://doi.org/10.1002/2017JC013067, 2017.
Ren, H., Sigman, D. M., Thunell, R. C., and Prokopenko, M. G.: Nitrogen
isotopic composition of planktonic foraminifera from the modern ocean and
recent sediments, Limnol. Oceanogr., 57, 1011–1024,
https://doi.org/10.4319/lo.2012.57.4.1011, 2012.
Revilla, M., Alexander, J., and Glibert, P. M.: Urea analysis in coastal
waters: comparison of enzymatic and direct methods, Limnol. Oceanogr.-Meth., 3,
290–299, https://doi.org/10.4319/lom.2005.3.290, 2005.
Rintoul, S. R. and Trull, T. W.: Seasonal evolution of the mixed layer in
the Subantarctic Zone south of Australia, J. Geophys. Res.-Oceans, 106,
31447–31462, https://doi.org/10.1029/2000JC000329, 2001.
Sallée, J. B., Speer, K. G., and Rintoul, S. R.: Zonally asymmetric
response of the Southern Ocean mixed-layer depth to the Southern Annular
Mode, Nat. Geosci., 3, 273–279, https://doi.org/10.1038/ngeo812, 2010.
Sambrotto, R. N. and Mace, B. J.: Coupling of biological and physical
regimes across the Antarctic Polar Front as reflected by nitrogen production
and recycling, Deep-Sea Res. Pt. II, 47, 3339–3367,
https://doi.org/10.1016/S0967-0645(00)00071-0, 2000.
Santoro, A. E., Sakamoto, C. M., Smith, J. M., Plant, J. N., Gehman, A. L., Worden, A. Z., Johnson, K. S., Francis, C. A., and Casciotti, K. L.: Measurements of nitrite production in and around the primary nitrite maximum in the central California Current, Biogeosciences, 10, 7395–7410, https://doi.org/10.5194/bg-10-7395-2013, 2013.
Sarmiento, J. L. and Orr, J. C.: Three-dimensional simulations of the impact
of Southern Ocean nutrient depletion on atmospheric CO2 and ocean chemistry,
Limnol. Oceanogr., 36, 1928–1950, https://doi.org/10.4319/lo.1991.36.8.1928,
1991.
Sarmiento, J. L. and Toggweiler, J. R.: A new model for the role of the
oceans in determining atmospheric pCO2, Nature, 308, 621–624,
https://doi.org/10.1038/308621a0, 1984.
Sarmiento, J. L., Gruber, N., Brzezinski, M. A., and Dunne, J. P.:
High-latitude controls of thermocline nutrients and low latitude biological
productivity, Nature, 427, 56–60, https://doi.org/10.1038/nature02127,
2004.
Savoye, N., Dehairs, F., Elskens, M., Cardinal, D., Kopczyńska, E. E.,
Trull, T. W., Wright, S., Baeyens, W., and Griffiths, F. B.: Regional
variation of spring N-uptake and new production in the Southern Ocean,
Geophys. Res. Lett., 31, L03301, https://doi.org/10.1029/2003GL018946, 2004.
Schaafsma, F. L., Cherel, Y., Flores, H., Franeker, J. A., Lea, M. A.,
Raymond, B., and Putte, A. P.: Review: the energetic value of zooplankton
and nekton species of the Southern Ocean, Mar. Biol., 165, 1–35,
https://doi.org/10.1007/s00227-018-3386-z, 2018.
Sedwick, P. N., Bowie, A. R., and Trull, T. W.: Dissolved iron in the
Australian sector of the Southern Ocean (CLIVAR SR3 section): Meridional and
seasonal trends, Deep-Sea Res. Pt. I, 55, 911–925,
https://doi.org/10.1016/j.dsr.2008.03.011, 2008.
Semeneh, M., Dehairs, F., Elskens, M., Baumann, M. E. M., Kopczynska, E. E.,
Lancelot, C., and Goeyens, L.: Nitrogen uptake regime and phytoplankton
community structure in the Atlantic and Indian sectors of the Southern
Ocean, J. Mar. Syst., 17, 159–177,
https://doi.org/10.1016/S0924-7963(98)00036-0, 1998.
Serebrennikova, Y. M. and Fanning, K. A.: Nutrients in the Southern Ocean
GLOBEC region: Variations, water circulation, and cycling, Deep-Sea Res. Pt. II, 51, 1981–2002, https://doi.org/10.1016/j.dsr2.2004.07.023, 2004.
Shadwick, E. H., Trull, T. W., Tilbrook, B., Sutton, A. J., Schulz, E., and
Sabine, C. L.: Seasonality of biological and physical controls on surface
ocean CO2 from hourly observations at the Southern Ocean Time Series site
south of Australia, Global Biogeochem. Cy., 29, 223–238,
https://doi.org/10.1002/2014GB004906, 2015.
Shafiee, R. T., Snow, J. T., Zhang, Q., and Rickaby, R. E.: Iron
requirements and uptake strategies of the globally abundant marine
ammonia-oxidising archaeon, Nitrosopumilus maritimus SCM1, ISME J., 13,
2295–2305, https://doi.org/10.1038/s41396-019-0434-8, 2019.
Shiozaki, T., Fujiwara, A., Ijichi, M., Harada, N., Nishino, S., Nishi, S.,
Nagata, T., and Hamasaki, K.: Diazotroph community structure and the role of
nitrogen fixation in the nitrogen cycle in the Chukchi Sea (western Arctic
Ocean), Limnol. Oceanogr., 63, 2191–2205, https://doi.org/10.1002/lno.10933,
2018.
Sigman, D. M. and Boyle, E. A.: Glacial/interglacial variations in
atmospheric carbon dioxide, Nature, 407, 859–869,
https://doi.org/10.1038/35038000, 2000.
Sigman, D. M., Altabet, M. A., McCorkle, D. C., Francois, R., and Fischer,
G.: The δ 15N of nitrate in the southern ocean: Consumption of
nitrate in surface waters, Global Biogeochem. Cy., 13, 1149–1166,
https://doi.org/10.1029/1999GB900038, 1999.
Smart, S. M., Fawcett, S. E., Thomalla, S. J., Weigand, M. A., Reason, C. J.
C., and Sigman, D. M.: Isotopic evidence for nitrification in the Antarctic
winter mixed layer, Global Biogeochem. Cy., 29, 427–445,
https://doi.org/10.1002/2014GB005013, 2015.
Smart, S. M., Fawcett, S. E., Ren, H., Schiebel, R., Tompkins, E. M.,
Martínez-García, A., Stirnimann, L., Roychoudhury, A., Haug, G.
H., and Sigman, D. M.: The Nitrogen Isotopic Composition of Tissue and
Shell-Bound Organic Matter of Planktic Foraminifera in Southern Ocean
Surface Waters, Geochem. Geophy. Geosy., 21, e2019GC008440,
https://doi.org/10.1029/2019GC008440, 2020.
Smith, S.: Biogeochemical data – 2017 Winter Cruise Atlantic-Indian Southern Ocean, Zenodo [data set], https://doi.org/10.5281/zenodo.3884606, 2020.
Smith, J. M., Chavez, F. P., and Francis, C. A.: Ammonium Uptake by
Phytoplankton Regulates Nitrification in the Sunlit Ocean, PLoS ONE, 9,
108173, https://doi.org/10.1371/journal.pone.0108173, 2014.
Smith Jr., W. O. and Harrison, W. G.: New production in polar regions: the
role of environmental controls, Deep-Sea Res., 38, 1463–1479,
https://doi.org/10.1016/0198-0149(91)90085-T, 1991.
Smith Jr., W. O., Marra, J., Hiscock, M. R. and Barber, R. T.: The seasonal
cycle of phytoplankton biomass and primary productivity in the Ross Sea,
Antarctica, Deep-Sea Res. Pt. II, 47, 3119–3140,
https://doi.org/10.1016/S0967-0645(00)00061-8, 2000.
Smith Jr., W. O. and Lancelot, C.: Bottom-up versus top-down control in
phytoplankton of the Southern Ocean, Antarct. Sci., 16, 531,
https://doi.org/10.1017/S0954102004002305, 2004.
Soares, M. A., Bhaskar, P. V., Naik, R. K., Dessai, D., George, J., Tiwari,
M., and Anilkumar, N.: Latitudinal δ13C and δ15N variations
in particulate organic matter (POM) in surface waters from the Indian ocean
sector of Southern Ocean and the Tropical Indian Ocean in 2012, Deep-Sea Res. Pt. II, 118, 186–196, https://doi.org/10.1016/j.dsr2.2015.06.009, 2015.
Sokolov, S. and Rintoul, S. R.: On the relationship between fronts of the
Antarctic Circumpolar Current and surface chlorophyll concentrations in the
Southern Ocean, J. Geophys. Res.-Oceans, 112, C07030,
https://doi.org/10.1029/2006JC004072, 2007.
Sosik, H. M. and Olson, R. J.: Phytoplankton and iron limitation of
photosynthetic efficiency in the Southern Ocean during late summer, Deep-Sea Res. Pt. I, 49, 1195–1216, https://doi.org/10.1016/S0967-0637(02)00015-8,
2002.
Steinberg, D. K. and Saba, G. K.: Nitrogen consumption and metabolism in
marine zooplankton, in: Nitrogen in the marine environment, edited by:
Capone, D. G., Bronk, D. A., Mulholland, M. R., and Carpenter, E. J.,
Elsevier Inc, 1135–1196,
https://doi.org/10.1016/B978-0-12-372522-6.00026-8, 2008.
Strickland, J. D. H. and Parsons, T. R. (Eds.): A practical handbook of seawater analysis, 2nd edition, Fisheries Research Board of Canada, Bulletin 167, Ottawa, 1972.
Sunda, W. G. and Huntsman, S. A.: Interrelated influence of iron, light and
cell size on marine phytoplankton growth, Nature, 390, 389–392,
https://doi.org/10.1038/37093, 1997.
Tagliabue, A., Mtshali, T., Aumont, O., Bowie, A. R., Klunder, M. B., Roychoudhury, A. N., and Swart, S.: A global compilation of dissolved iron measurements: focus on distributions and processes in the Southern Ocean, Biogeosciences, 9, 2333–2349, https://doi.org/10.5194/bg-9-2333-2012, 2012.
Tagliabue, A., Sallée, J. B., Bowie, A. R., Lévy, M., Swart, S., and
Boyd, P. W.: Surface-water iron supplies in the Southern Ocean sustained by
deep winter mixing, Nat. Geosci., 7, 314–320,
https://doi.org/10.1038/ngeo2101, 2014.
Takao, S., Hirawake, T., Wright, S. W., and Suzuki, K.: Variations of net primary productivity and phytoplankton community composition in the Indian sector of the Southern Ocean as estimated from ocean color remote sensing data, Biogeosciences, 9, 3875–3890, https://doi.org/10.5194/bg-9-3875-2012, 2012.
Tevlin, A. G. and Murphy, J. G.: Atmospheric Ammonia: Measurements,
Modeling, and Chemistry–Climate Interactions, in: Advances In Atmospheric
Chemistry-Volume 2: Organic Oxidation And Multiphase Chemistry, edited by:
Barker, J. R., Steiner, A. L., and Wallington, T. J., 2, 1,
https://doi.org/10.1142/9789813271838_ 0001, 2019.
Thomalla, S. J., Waldron, H. N., Lucas, M. I., Read, J. F., Ansorge, I. J., and Pakhomov, E.: Phytoplankton distribution and nitrogen dynamics in the southwest indian subtropical gyre and Southern Ocean waters, Ocean Sci., 7, 113–127, https://doi.org/10.5194/os-7-113-2011, 2011.
Timmermans, K. R., Van Leeuwe, M. A., De Jong, J. T. M., McKay, R. M. L.,
Nolting, R. F., Witte, H. J., Van Ooyen, J., Swagerman, M. J. W.,
Kloosterhuis, H., and De Baar, H. J.: Iron stress in the Pacific region of
the Southern Ocean: evidence from enrichment bioassays, Mar. Ecol. Prog. Ser.,
166, 27–41, https://doi.org/10.3354/meps166027, 1998.
Tréguer, P. and Jacques, G.: Review Dynamics of nutrients and
phytoplankton, and fluxes of carbon, nitrogen and silicon in the Antarctic
Ocean, in: Weddell Sea Ecology, edited by: Hempel, G., Springer, Berlin,
Heidelberg, 149–162, https://doi.org/10.1007/978-3-642-77595-6, 1992.
Treibergs, L. A., Fawcett, S. E., Lomas, M. W., and Sigman, D. M.: Nitrogen
isotopic response of prokaryotic and eukaryotic phytoplankton to nitrate
availability in Sargasso Sea surface waters, Limnol. Oceanogr., 59, 972–985,
https://doi.org/10.4319/lo.2014.59.3.0972, 2014.
Trull, T. W., Davies, D., and Casciotti, K.: Insights into nutrient
assimilation and export in naturally iron-fertilized waters of the Southern
Ocean from nitrogen, carbon and oxygen isotopes, Deep-Sea Res. Pt. II, 55,
820–840, https://doi.org/10.1016/j.dsr2.2007.12.035, 2008.
Tupas, L. and Koike, I.: Amino acid and ammonium utilization by
heterotrophic marine bacteria grown in enriched seawater, Limnol. Oceanogr.,
35, 1145–1155, https://doi.org/10.4319/lo.1990.35.5.1145, 1990.
Utermöhl, H.: Zur vervollkommnung der quantitativen
phytoplankton-methodik: mit 1 Tabelle und 15 abbildungen im Text und auf 1
Tafel, Internationale Vereinigung für theoretische und angewandte
Limnologie: Mitteilungen, 9, 1–38, 1958.
Vaulot, D., Courties, C., and Partensky, F.: A simple method to preserve
oceanic phytoplankton for flow cytometric analyses, Cytometry, 10, 629–635,
https://doi.org/10.1002/cyto.990100519, 1989.
Viljoen, J. J., Weir, I., Fietz, S., Cloete, R., Loock, J., Philibert, R.,
and Roychoudhury, A. N.: Links between the phytoplankton community
composition and trace metal distribution in summer surface waters of the
Atlantic southern ocean, Front. Mar. Sci., 6, 295,
https://doi.org/10.3389/fmars.2019.00295, 2019.
Volk, T. and Hoffert, M. I.: Ocean carbon pumps: Analysis of relative
strengths and efficiencies in ocean-driven atmospheric CO2 changes, in: The
carbon cycle and atmospheric CO2: natural variations Archean to present,
edited by: Sundquist, E., and Broecker, W., 32, 99–110,
https://doi.org/10.1029/GM032p0099, 1985.
Wadley, M. R., Jickells, T. D., and Heywood, K. J.: The role of iron sources
and transport for Southern Ocean productivity, Deep-Sea Res. Pt. I, 87,
82–94, https://doi.org/10.1016/j.dsr.2014.02.003, 2014.
Wan, X. S., Sheng, H. X., Dai, M., Zhang, Y., Shi, D., Trull, T. W., Zhu,
Y., Lomas, M. W., and Kao, S. J.: Ambient nitrate switches the ammonium
consumption pathway in the euphotic ocean, Nat. Commun., 9, 1–9,
https://doi.org/10.1038/s41467-018-03363-0, 2018.
Ward, B. B.: Light and substrate concentration relationships with marine
ammonium assimilation and oxidation rates, Mar. Chem., 16, 301–316,
https://doi.org/10.1016/0304-4203(85)90052-0, 1985.
Ward, B. B.: Temporal variability in nitrification rates and related
biogeochemical factors in Monterey Bay, Mar. Ecol. Prog. Ser., 292, 97–109,
https://doi.org/10.3354/meps29207, 2005.
Ward, B. B.: Measurement and distribution of nitrification rates in the oceans, Method Enzymol., 486, 307–323, https://doi.org/10.1016/B978-0-12-381294-0.00013-4, 2011.
Weber, L. H. and El-Sayed, S. Z.: Contributions of the net, nano-and
picoplankton to the phytoplankton standing crop and primary productivity in
the Southern Ocean, J. Plankton Res., 9, 973–994,
https://doi.org/10.1093/plankt/9.5.973, 1987.
Wei, T. and Simko, V.: R package “corrplot”: Visualization of a
Correlation Matrix v0.84, https://github.com/taiyun/corrplot, 2017.
Weir, I., Fawcett, S., Smith, S., Walker, D., Bornman, T., and Fietz, S.:
Winter biogenic silica and diatom distributions in the Indian sector of the
Southern Ocean, Deep-Sea Res. Pt. I, 166, 103421,
https://doi.org/10.1016/j.dsr.2020.103421, 2020.
Welschmeyer, N. A.: Fluorometric analysis of chlorophyll a in the presence
of chlorophyll b and pheopigments, Limnol. Oceanogr., 39, 1985–1992,
https://doi.org/10.4319/lo.1994.39.8.1985, 1994.
Wickham, H.: ggplot2: Elegant Graphics for Data Analysis, Springer-Verlag
New York, ISBN 978-3-319-24277-4, 2016.
Wickham, H. and Seidel, D.: scales: scale functions for visualisation, R package version 1.1.1, https://CRAN.R-project.org/package=scales, 2020.
Wood, S.: Generalized Additive Models: An Introduction with R, 2nd edition, Chapman and Hall/CRC, ISBN 9781498728331, 2017.
Xu, G., Chen, L., Zhang, M., Zhang, Y., Wang, J., and Lin, Q.: Year-round
records of bulk aerosol composition over the Zhongshan Station, Coastal East
Antarctica, Air. Qual. Atmos. Hlth., 12, 271–288,
https://doi.org/10.1007/s11869-018-0642-9, 2019.
Yool, A., Martin, A. P., Fernández, C., and Clark, D. R.: The
significance of nitrification for oceanic new production, Nature, 447,
999–1002, https://doi.org/10.1038/nature05885, 2007.
Zakem, E. J., Al-Haj, A., Church, M. J., Van Dijken, G. L., Dutkiewicz, S.,
Foster, S. Q., Fulweiler, R. W., Mills, M. M., and Follows, M. J.:
Ecological control of nitrite in the upper ocean, Nat. Commun., 9, 1–13,
https://doi.org/10.1038/s41467-018-03553-w, 2018.
Zhou, J., Delille, B., Kaartokallio, H., Kattner, G., Kuosa, H., Tison, J.
L., Autio, R., Dieckmann, G. S., Evers, K. U., Jørgensen, L., and
Kennedy, H.: Physical and bacterial controls on inorganic nutrients and
dissolved organic carbon during a sea ice growth and decay experiment, Mar.
Chem., 166, 59–69, https://doi.org/10.1016/j.marchem.2014.09.013, 2014.
Short summary
Ammonium is a crucial yet poorly understood component of the Southern Ocean nitrogen cycle. We attribute our finding of consistently high ammonium concentrations in the winter mixed layer to limited ammonium consumption and sustained ammonium production, conditions under which the Southern Ocean becomes a source of carbon dioxide to the atmosphere. From similar data collected over an annual cycle, we propose a seasonal cycle for ammonium in shallow polar waters – a first for the Southern Ocean.
Ammonium is a crucial yet poorly understood component of the Southern Ocean nitrogen cycle. We...
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