Articles | Volume 15, issue 9
https://doi.org/10.5194/bg-15-2961-2018
© Author(s) 2018. 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-15-2961-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
16 May 2018
Research article |
| 16 May 2018
| 16 May 2018
Nutrient availability and the ultimate control of the biological carbon pump in the western tropical South Pacific Ocean
Thierry Moutin
CORRESPONDING AUTHOR
Aix Marseille Univ., CNRS, Université de Toulon, IRD,
OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110,
13288, Marseille, France
Thibaut Wagener
Aix Marseille Univ., CNRS, Université de Toulon, IRD,
OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110,
13288, Marseille, France
Mathieu Caffin
Aix Marseille Univ., CNRS, Université de Toulon, IRD,
OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110,
13288, Marseille, France
Alain Fumenia
Aix Marseille Univ., CNRS, Université de Toulon, IRD,
OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110,
13288, Marseille, France
Audrey Gimenez
Aix Marseille Univ., CNRS, Université de Toulon, IRD,
OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110,
13288, Marseille, France
Melika Baklouti
Aix Marseille Univ., CNRS, Université de Toulon, IRD,
OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110,
13288, Marseille, France
Pascale Bouruet-Aubertot
Sorbonne Universités – UPMC Univ. Paris 06 – LOCEAN, BP100, 4
place Jussieu, 75252 Paris CEDEX 05, France
Mireille Pujo-Pay
Laboratoire d'Océanographie Microbienne – UMR 7321, CNRS –
Sorbonne Universités, UPMC Univ Paris 06, Observatoire
Océanologique, 66650 Banyuls-sur-mer, France
Karine Leblanc
Aix Marseille Univ., CNRS, Université de Toulon, IRD,
OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110,
13288, Marseille, France
Dominique Lefevre
Aix Marseille Univ., CNRS, Université de Toulon, IRD,
OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110,
13288, Marseille, France
Sandra Helias Nunige
Aix Marseille Univ., CNRS, Université de Toulon, IRD,
OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110,
13288, Marseille, France
Nathalie Leblond
Observatoire Océanologique de Villefranche, Laboratoire
d'Océanographie de Villefranche, UMR 7093, Villefranche-sur-mer, France
Olivier Grosso
Aix Marseille Univ., CNRS, Université de Toulon, IRD,
OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110,
13288, Marseille, France
Alain de Verneil
Aix Marseille Univ., CNRS, Université de Toulon, IRD,
OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110,
13288, Marseille, France
The Center for Prototype Climate Modeling, New York University in Abu Dhabi, Abu Dhabi, UAE
Related authors
Thierry Moutin
Biogeosciences, 16, 1673–1673, https://doi.org/10.5194/bg-16-1673-2019, https://doi.org/10.5194/bg-16-1673-2019, 2019
Pascale Bouruet-Aubertot, Yannis Cuypers, Andrea Doglioli, Mathieu Caffin, Christophe Yohia, Alain de Verneil, Anne Petrenko, Dominique Lefèvre, Hervé Le Goff, Gilles Rougier, Marc Picheral, and Thierry Moutin
Biogeosciences, 15, 7485–7504, https://doi.org/10.5194/bg-15-7485-2018, https://doi.org/10.5194/bg-15-7485-2018, 2018
Short summary
Short summary
The OUTPACE cruise took place between New Caledonia and French Polynesia. The main purpose was to understand how micro-organisms can survive in a very poor environment. One main source of nutrients is at depth, below the euphotic layer where micro-organisms live. The purpose of the turbulence measurements was to determine to which extent turbulence may
upliftnutrients into the euphotic layer. The origin of the turbulence that was found contrasted along the transect was also determined.
Audrey Gimenez, Melika Baklouti, Thibaut Wagener, and Thierry Moutin
Biogeosciences, 15, 6573–6589, https://doi.org/10.5194/bg-15-6573-2018, https://doi.org/10.5194/bg-15-6573-2018, 2018
Short summary
Short summary
During the OUTPACE cruise conducted in the oligotrophic to ultra-oligotrophic region of the western tropical South Pacific, two contrasted regions were sampled in terms of N2 fixation rates, primary production rates and nutrient availability. The aim of this work was to investigate the role of N2 fixation in the differences observed between the two contrasted areas by comparing two simulations only differing by the presence or not of N2 fixers using a 1-D biogeochemical–physical coupled model.
Thibaut Wagener, Nicolas Metzl, Mathieu Caffin, Jonathan Fin, Sandra Helias Nunige, Dominique Lefevre, Claire Lo Monaco, Gilles Rougier, and Thierry Moutin
Biogeosciences, 15, 5221–5236, https://doi.org/10.5194/bg-15-5221-2018, https://doi.org/10.5194/bg-15-5221-2018, 2018
Short summary
Short summary
The western tropical South Pacific was sampled along a longitudinal 4000 km transect (OUTPACE cruise) for the measurement of carbonate parameters (total alkalinity and total inorganic carbon) between the Melanesian Archipelago and the western part of the South Pacific gyre. This paper reports this new dataset and derived properties. We also estimate anthropogenic carbon distribution in the water column using the TrOCA method.
France Van Wambeke, Audrey Gimenez, Solange Duhamel, Cécile Dupouy, Dominique Lefevre, Mireille Pujo-Pay, and Thierry Moutin
Biogeosciences, 15, 2669–2689, https://doi.org/10.5194/bg-15-2669-2018, https://doi.org/10.5194/bg-15-2669-2018, 2018
Short summary
Short summary
The western tropical South Pacific Ocean has recently been shown to be a hotspot for biological nitrogen fixation. In this study, we examined the horizontal and vertical distribution of heterotrophic prokaryotic production alongside photosynthetic rates, nitrogen fixation rates and phosphate turnover times across the western tropical South Pacific Ocean, in order to relate these fluxes to bottom–up controls (related to nitrogen, phosphate and labile C availability).
Angela N. Knapp, Kelly M. McCabe, Olivier Grosso, Nathalie Leblond, Thierry Moutin, and Sophie Bonnet
Biogeosciences, 15, 2619–2628, https://doi.org/10.5194/bg-15-2619-2018, https://doi.org/10.5194/bg-15-2619-2018, 2018
Short summary
Short summary
The spatial distribution of biological N2 fixation fluxes to the ocean remains poorly constrained. Here we use nitrogen isotope budgets to identify significant N2 fixation inputs to the western tropical South Pacific (WTSP), where N2 fixation supports > 50 % of export production at stations proximal to iron sources. The significant N2 fixation inputs in the WTSP may offset nitrogen loss in the oxygen-deficient zones of the eastern tropical South Pacific.
Mathieu Caffin, Thierry Moutin, Rachel Ann Foster, Pascale Bouruet-Aubertot, Andrea Michelangelo Doglioli, Hugo Berthelot, Cécile Guieu, Olivier Grosso, Sandra Helias-Nunige, Nathalie Leblond, Audrey Gimenez, Anne Alexandra Petrenko, Alain de Verneil, and Sophie Bonnet
Biogeosciences, 15, 2565–2585, https://doi.org/10.5194/bg-15-2565-2018, https://doi.org/10.5194/bg-15-2565-2018, 2018
Short summary
Short summary
We performed N budgets to assess the role of N2 fixation on production and export in the western tropical South Pacific Ocean. We deployed a combination of techniques including high-sensitivity measurements of N input and sediment traps deployment. We demonstrated that N2 fixation was the major source of new N before atmospheric deposition and upward nitrate fluxes. It contributed significantly to organic matter export, indicating a high efficiency of this region to export carbon.
Alain de Verneil, Louise Rousselet, Andrea M. Doglioli, Anne A. Petrenko, Christophe Maes, Pascale Bouruet-Aubertot, and Thierry Moutin
Biogeosciences, 15, 2125–2147, https://doi.org/10.5194/bg-15-2125-2018, https://doi.org/10.5194/bg-15-2125-2018, 2018
Short summary
Short summary
Oceanographic campaigns to measure biogeochemical processes popularly deploy drifters with onboard incubations to stay in a single body of water. Here, we aggregate physical data taken during such a cruise, OUTPACE, to independently test in a new approach whether the drifter really stayed in what can be considered a single biological or chemical environment. This study concludes that future campaigns would benefit from similar data collection and analysis to validate their sampling strategy.
Alain Fumenia, Thierry Moutin, Sophie Bonnet, Mar Benavides, Anne Petrenko, Sandra Helias Nunige, and Christophe Maes
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-557, https://doi.org/10.5194/bg-2017-557, 2018
Revised manuscript not accepted
Short summary
Short summary
The Melanesian archipelago waters between 160° E and 170° W are characterized by a significant N2 fixation rates and an excess of particulate organic nitrogen compared to the canonical ratio of Redfield and a positive N*. We hypothesize that the southern branch of the subtropical gyre is probably the main vector of excess nitrogen transport in the thermocline waters showing an influence of nitrogen fixation occurring in the western tropical in a large part of the South Pacific.
Alain de Verneil, Louise Rousselet, Andrea M. Doglioli, Anne A. Petrenko, and Thierry Moutin
Biogeosciences, 14, 3471–3486, https://doi.org/10.5194/bg-14-3471-2017, https://doi.org/10.5194/bg-14-3471-2017, 2017
Short summary
Short summary
A surface summer plankton bloom in the western tropical South Pacific was sampled during the Oligotrophy to UlTra-oligotrophy PACific Experiment (OUTPACE) cruise. We characterize the bloom's properties and the circulation responsible for its evolution. Nitrogen fixation helped sustain the bloom, and larger-scale flows, rather than the smaller ones, explain its movements. Future studies of blooms in this region can make use of these findings to track the horizontal export of plankton production.
Thierry Moutin, Andrea Michelangelo Doglioli, Alain de Verneil, and Sophie Bonnet
Biogeosciences, 14, 3207–3220, https://doi.org/10.5194/bg-14-3207-2017, https://doi.org/10.5194/bg-14-3207-2017, 2017
Short summary
Short summary
The overall goal of OUTPACE was to obtain a successful representation of the interactions between planktonic organisms and the cycle of biogenic elements in the western tropical South Pacific Ocean across trophic and N2 fixation gradients. The international OUTPACE cruise took place between 18 February and 3 April 2015 aboard the RV L’Atalante and involved 60 scientists. The transect covered ~4 000 km from the western part of the Melanesian archipelago to the western boundary of the gyre.
Audrey Gimenez, Melika Baklouti, Sophie Bonnet, and Thierry Moutin
Biogeosciences, 13, 5103–5120, https://doi.org/10.5194/bg-13-5103-2016, https://doi.org/10.5194/bg-13-5103-2016, 2016
Short summary
Short summary
In the context of the VAHINE mesocosm experiment in the Nouméa lagoon (New Caledonia), a 1-D vertical biogeochemical mechanistic model was used together with the in situ experiment to complement our comprehension of the planktonic ecosystem dynamics and the main biogeochemical carbon, nitrogen and phosphate fluxes. The model also showed the fate of fixed N2 by providing, over time, the proportion of diazotroph-derived nitrogen (DDN) in each compartment (mineral and organic) of the model.
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
Short summary
Short summary
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.
Ilana Berman-Frank, Dina Spungin, Eyal Rahav, France Van Wambeke, Kendra Turk-Kubo, and Thierry Moutin
Biogeosciences, 13, 3793–3805, https://doi.org/10.5194/bg-13-3793-2016, https://doi.org/10.5194/bg-13-3793-2016, 2016
Short summary
Short summary
In the marine environment, sticky sugar-containing gels, termed transparent exopolymeric particles (TEP), are produced from biological sources and physical and chemical processes. These compounds are essential vectors enhancing downward flow of organic matter and its storage at depth. Spatial and temporal dynamics of TEPs were followed for 23 days during the VAHINE mesocosm experiment that investigated the fate of nitrogen and carbon derived from organisms fixing atmospheric N2 (diazotrophs).
France Van Wambeke, Ulrike Pfreundt, Aude Barani, Hugo Berthelot, Thierry Moutin, Martine Rodier, Wolfgang R. Hess, and Sophie Bonnet
Biogeosciences, 13, 3187–3202, https://doi.org/10.5194/bg-13-3187-2016, https://doi.org/10.5194/bg-13-3187-2016, 2016
Short summary
Short summary
The phytoplankton is at the base of the plankton food web in large parts of oceanic "deserts" such as the South Pacific Ocean, where nitrogen sources limit activity. Mesocosms were fertilized with phosphorus to stimulate diazotrophy (atmospheric N2 fixation). Mostly diazotroph-derived nitrogen fuelled the heterotrophic bacterial community through indirect processes generating dissolved organic matter and detritus, such as mortality, lysis and grazing of both diazotrophs and non-diazotrophs.
Sophie Bonnet, Thierry Moutin, Martine Rodier, Jean-Michel Grisoni, Francis Louis, Eric Folcher, Bertrand Bourgeois, Jean-Michel Boré, and Armelle Renaud
Biogeosciences, 13, 2803–2814, https://doi.org/10.5194/bg-13-2803-2016, https://doi.org/10.5194/bg-13-2803-2016, 2016
Short summary
Short summary
e main goal of the VAHINE project was to study the fate of N2 fixation in the ocean. Three large-volume (~ 50 m3) mesocosms were deployed in a tropical oligotrophic ecosystem (the New Caledonia lagoon, south-eastern Pacific). This introductory paper describes the scientific objectives of the project in detail as well as the implementation plan: the mesocosm description and deployment, the selection of the study site, and the logistical and sampling strategy.
A. Guyennon, M. Baklouti, F. Diaz, J. Palmieri, J. Beuvier, C. Lebaupin-Brossier, T. Arsouze, K. Béranger, J.-C. Dutay, and T. Moutin
Biogeosciences, 12, 7025–7046, https://doi.org/10.5194/bg-12-7025-2015, https://doi.org/10.5194/bg-12-7025-2015, 2015
Short summary
Short summary
Dissolved organic carbon (DOC) has already been identified as a potentially significant source of carbon export in the Mediterranean Sea, though in situ export estimations are scarce. This work provides a thorough analysis at basin scale of carbon export with the coupled model NEMO-MED12/Eco3M-MED model. The seasonality and the processes of particulate and dissolved carbon production are also investigated. DOC export appears to be dominant in most regions, especially in the eastern basin.
H. Berthelot, T. Moutin, S. L'Helguen, K. Leblanc, S. Hélias, O. Grosso, N. Leblond, B. Charrière, and S. Bonnet
Biogeosciences, 12, 4099–4112, https://doi.org/10.5194/bg-12-4099-2015, https://doi.org/10.5194/bg-12-4099-2015, 2015
A. Talarmin, F. Van Wambeke, P. Lebaron, and T. Moutin
Biogeosciences, 12, 1237–1247, https://doi.org/10.5194/bg-12-1237-2015, https://doi.org/10.5194/bg-12-1237-2015, 2015
Short summary
Short summary
Along a transect in the warm nutrient-depleted Mediterranean Sea, we found that microorganisms shared phosphate resources by using different uptake strategies. Heterotrophic prokaryotes dominated phosphate uptake in the upper layers while cyanobacteria dominated uptake fluxes around the deep chlorophyll maximum depth. Synechococcus seemed well equipped to respond to pulses of phosphate, whereas Prochlorococcus and heterotrophs were more adapted to very low concentrations.
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
Short summary
Short summary
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.
Nicolas Metzl, Jonathan Fin, Claire Lo Monaco, Claude Mignon, Samir Alliouane, David Antoine, Guillaume Bourdin, Jacqueline Boutin, Yann Bozec, Pascal Conan, Laurent Coppola, Frédéric Diaz, Eric Douville, Xavier Durrieu de Madron, Jean-Pierre Gattuso, Frédéric Gazeau, Melek Golbol, Bruno Lansard, Dominique Lefèvre, Nathalie Lefèvre, Fabien Lombard, Férial Louanchi, Liliane Merlivat, Léa Olivier, Anne Petrenko, Sébastien Petton, Mireille Pujo-Pay, Christophe Rabouille, Gilles Reverdin, Céline Ridame, Aline Tribollet, Vincenzo Vellucci, Thibaut Wagener, and Cathy Wimart-Rousseau
Earth Syst. Sci. Data, 16, 89–120, https://doi.org/10.5194/essd-16-89-2024, https://doi.org/10.5194/essd-16-89-2024, 2024
Short summary
Short summary
This work presents a synthesis of 44 000 total alkalinity and dissolved inorganic carbon observations obtained between 1993 and 2022 in the Global Ocean and the Mediterranean Sea at the surface and in the water column. Seawater samples were measured using the same method and calibrated with international Certified Reference Material. We describe the data assemblage, quality control and some potential uses of this dataset.
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
Short summary
Short summary
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.
Lucille Barré, Frédéric Diaz, Thibaut Wagener, France Van Wambeke, Camille Mazoyer, Christophe Yohia, and Christel Pinazo
Geosci. Model Dev., 16, 6701–6739, https://doi.org/10.5194/gmd-16-6701-2023, https://doi.org/10.5194/gmd-16-6701-2023, 2023
Short summary
Short summary
While several studies have shown that mixotrophs play a crucial role in the carbon cycle, the impact of environmental forcings on their dynamics remains poorly investigated. Using a biogeochemical model that considers mixotrophs, we study the impact of light and nutrient concentration on the ecosystem composition in a highly dynamic Mediterranean coastal area: the Bay of Marseille. We show that mixotrophs cope better with oligotrophic conditions compared to strict auto- and heterotrophs.
Lucille Barré, Frédéric Diaz, Thibaut Wagener, Camille Mazoyer, Christophe Yohia, and Christel Pinazo
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2023-34, https://doi.org/10.5194/gmd-2023-34, 2023
Revised manuscript accepted for GMD
Short summary
Short summary
Carbonate system is typically studied using measurements, yet modelling can contribute valuable insights. Using a biogeochemical model, we propose a new representation of total alkalinity, dissolved inorganic carbon, pCO2 and pH in a highly dynamic Mediterranean coastal area: the Bay of Marseille, a useful addition to measurements. Through a detailed analysis of pCO2 and air-sea CO2 fluxes we show that their variations are strongly impacted by the hydrodynamic processes that affect the bay.
Alain de Verneil, Zouhair Lachkar, Shafer Smith, and Marina Lévy
Biogeosciences, 19, 907–929, https://doi.org/10.5194/bg-19-907-2022, https://doi.org/10.5194/bg-19-907-2022, 2022
Short summary
Short summary
The Arabian Sea is a natural CO2 source to the atmosphere, but previous work highlights discrepancies between data and models in estimating air–sea CO2 flux. In this study, we use a regional ocean model, achieve a flux closer to available data, and break down the seasonal cycles that impact it, with one result being the great importance of monsoon winds. As demonstrated in a meta-analysis, differences from data still remain, highlighting the great need for further regional data collection.
Matthieu Bressac, Thibaut Wagener, Nathalie Leblond, Antonio Tovar-Sánchez, Céline Ridame, Vincent Taillandier, Samuel Albani, Sophie Guasco, Aurélie Dufour, Stéphanie H. M. Jacquet, François Dulac, Karine Desboeufs, and Cécile Guieu
Biogeosciences, 18, 6435–6453, https://doi.org/10.5194/bg-18-6435-2021, https://doi.org/10.5194/bg-18-6435-2021, 2021
Short summary
Short summary
Phytoplankton growth is limited by the availability of iron in about 50 % of the ocean. Atmospheric deposition of desert dust represents a key source of iron. Here, we present direct observations of dust deposition in the Mediterranean Sea. A key finding is that the input of iron from dust primarily occurred in the deep ocean, while previous studies mainly focused on the ocean surface. This new insight will enable us to better represent controls on global marine productivity in models.
Elvira Pulido-Villena, Karine Desboeufs, Kahina Djaoudi, France Van Wambeke, Stéphanie Barrillon, Andrea Doglioli, Anne Petrenko, Vincent Taillandier, Franck Fu, Tiphanie Gaillard, Sophie Guasco, Sandra Nunige, Sylvain Triquet, and Cécile Guieu
Biogeosciences, 18, 5871–5889, https://doi.org/10.5194/bg-18-5871-2021, https://doi.org/10.5194/bg-18-5871-2021, 2021
Short summary
Short summary
We report on phosphorus dynamics in the surface layer of the Mediterranean Sea. Highly sensitive phosphate measurements revealed vertical gradients above the phosphacline. The relative contribution of diapycnal fluxes to total external supply of phosphate to the mixed layer decreased towards the east, where atmospheric deposition dominated. Taken together, external sources of phosphate contributed little to total supply, which was mainly sustained by enzymatic hydrolysis of organic phosphorus.
Frédéric Gazeau, Céline Ridame, France Van Wambeke, Samir Alliouane, Christian Stolpe, Jean-Olivier Irisson, Sophie Marro, Jean-Michel Grisoni, Guillaume De Liège, Sandra Nunige, Kahina Djaoudi, Elvira Pulido-Villena, Julie Dinasquet, Ingrid Obernosterer, Philippe Catala, and Cécile Guieu
Biogeosciences, 18, 5011–5034, https://doi.org/10.5194/bg-18-5011-2021, https://doi.org/10.5194/bg-18-5011-2021, 2021
Short summary
Short summary
This paper shows that the impacts of Saharan dust deposition in different Mediterranean basins are as strong as those observed in coastal waters but differed substantially between the three tested stations, differences attributed to variable initial metabolic states. A stronger impact of warming and acidification on mineralization suggests a decreased capacity of Mediterranean surface communities to sequester CO2 following the deposition of atmospheric particles in the coming decades.
Matthieu Roy-Barman, Lorna Foliot, Eric Douville, Nathalie Leblond, Fréderic Gazeau, Matthieu Bressac, Thibaut Wagener, Céline Ridame, Karine Desboeufs, and Cécile Guieu
Biogeosciences, 18, 2663–2678, https://doi.org/10.5194/bg-18-2663-2021, https://doi.org/10.5194/bg-18-2663-2021, 2021
Short summary
Short summary
The release of insoluble elements such as aluminum (Al), iron (Fe), rare earth elements (REEs), thorium (Th) and protactinium (Pa) when Saharan dust falls over the Mediterranean Sea was studied during tank experiments under present and future climate conditions. Each element exhibited different dissolution kinetics and dissolution fractions (always lower than a few percent). Changes in temperature and/or pH under greenhouse conditions lead to a lower Th release and a higher light REE release.
Stéphanie H. M. Jacquet, Dominique Lefèvre, Christian Tamburini, Marc Garel, Frédéric A. C. Le Moigne, Nagib Bhairy, and Sophie Guasco
Biogeosciences, 18, 2205–2212, https://doi.org/10.5194/bg-18-2205-2021, https://doi.org/10.5194/bg-18-2205-2021, 2021
Short summary
Short summary
We present new data concerning the relation between biogenic barium (Baxs, a tracer of carbon remineralization at mesopelagic depths), O2 consumption and prokaryotic heterotrophic production (PHP) in the Mediterranean Sea. The purpose of this paper is to improve our understanding of the relation between Baxs, PHP and O2 and to test the validity of the Dehairs transfer function in the Mediterranean Sea. This relation has never been tested in the Mediterranean Sea.
Caroline Ulses, Claude Estournel, Marine Fourrier, Laurent Coppola, Fayçal Kessouri, Dominique Lefèvre, and Patrick Marsaleix
Biogeosciences, 18, 937–960, https://doi.org/10.5194/bg-18-937-2021, https://doi.org/10.5194/bg-18-937-2021, 2021
Short summary
Short summary
We analyse the seasonal cycle of O2 and estimate an annual O2 budget in the north-western Mediterranean deep-convection region, using a numerical model. We show that this region acts as a large sink of atmospheric O2 and as a major source of O2 for the western Mediterranean Sea. The decrease in the deep convection intensity predicted in recent projections may have important consequences on the overall uptake of O2 in the Mediterranean Sea and on the O2 exchanges with the Atlantic Ocean.
Katixa Lajaunie-Salla, Frédéric Diaz, Cathy Wimart-Rousseau, Thibaut Wagener, Dominique Lefèvre, Christophe Yohia, Irène Xueref-Remy, Brian Nathan, Alexandre Armengaud, and Christel Pinazo
Geosci. Model Dev., 14, 295–321, https://doi.org/10.5194/gmd-14-295-2021, https://doi.org/10.5194/gmd-14-295-2021, 2021
Short summary
Short summary
A biogeochemical model of planktonic food webs including a carbonate balance module is applied in the Bay of Marseille (France) to represent the carbon marine cycle expected to change in the future owing to significant increases in anthropogenic emissions of CO2. The model correctly simulates the ranges and seasonal dynamics of most variables of the carbonate system (pH). This study shows that external physical forcings have an important impact on the carbonate equilibrium in this coastal area.
Kahina Djaoudi, France Van Wambeke, Aude Barani, Nagib Bhairy, Servanne Chevaillier, Karine Desboeufs, Sandra Nunige, Mohamed Labiadh, Thierry Henry des Tureaux, Dominique Lefèvre, Amel Nouara, Christos Panagiotopoulos, Marc Tedetti, and Elvira Pulido-Villena
Biogeosciences, 17, 6271–6285, https://doi.org/10.5194/bg-17-6271-2020, https://doi.org/10.5194/bg-17-6271-2020, 2020
Antonio Tovar-Sánchez, Araceli Rodríguez-Romero, Anja Engel, Birthe Zäncker, Franck Fu, Emilio Marañón, María Pérez-Lorenzo, Matthieu Bressac, Thibaut Wagener, Sylvain Triquet, Guillaume Siour, Karine Desboeufs, and Cécile Guieu
Biogeosciences, 17, 2349–2364, https://doi.org/10.5194/bg-17-2349-2020, https://doi.org/10.5194/bg-17-2349-2020, 2020
Short summary
Short summary
Residence times of particulate metals derived from aerosol deposition in the Sea Surface Microlayer of the Mediterranean Sea ranged from a couple of minutes (e.g., for Fe) to a few hours (e.g., for Cu). Microbial activity seems to play an important role in in this process and in the concentration and distribution of metals between diferent water layers.
Thierry Moutin
Biogeosciences, 16, 1673–1673, https://doi.org/10.5194/bg-16-1673-2019, https://doi.org/10.5194/bg-16-1673-2019, 2019
Christos Panagiotopoulos, Mireille Pujo-Pay, Mar Benavides, France Van Wambeke, and Richard Sempéré
Biogeosciences, 16, 105–116, https://doi.org/10.5194/bg-16-105-2019, https://doi.org/10.5194/bg-16-105-2019, 2019
Pascale Bouruet-Aubertot, Yannis Cuypers, Andrea Doglioli, Mathieu Caffin, Christophe Yohia, Alain de Verneil, Anne Petrenko, Dominique Lefèvre, Hervé Le Goff, Gilles Rougier, Marc Picheral, and Thierry Moutin
Biogeosciences, 15, 7485–7504, https://doi.org/10.5194/bg-15-7485-2018, https://doi.org/10.5194/bg-15-7485-2018, 2018
Short summary
Short summary
The OUTPACE cruise took place between New Caledonia and French Polynesia. The main purpose was to understand how micro-organisms can survive in a very poor environment. One main source of nutrients is at depth, below the euphotic layer where micro-organisms live. The purpose of the turbulence measurements was to determine to which extent turbulence may
upliftnutrients into the euphotic layer. The origin of the turbulence that was found contrasted along the transect was also determined.
François Carlotti, Marc Pagano, Loïc Guilloux, Katty Donoso, Valentina Valdés, Olivier Grosso, and Brian P. V. Hunt
Biogeosciences, 15, 7273–7297, https://doi.org/10.5194/bg-15-7273-2018, https://doi.org/10.5194/bg-15-7273-2018, 2018
Short summary
Short summary
The paper characterizes the zooplankton community and plankton food web processes between New Caledonia and Tahiti (tropical South Pacific) during the austral summer 2015. In this region, the pelagic production depends on N2 fixation by diazotroph microorganisms on which the zooplankton community feeds, supporting a pelagic food chain ending with valuable tuna fisheries. We estimated a contribution of up to 75 % of diazotroph‐derived nitrogen to zooplankton biomass in the Melanesian archipelago.
Audrey Gimenez, Melika Baklouti, Thibaut Wagener, and Thierry Moutin
Biogeosciences, 15, 6573–6589, https://doi.org/10.5194/bg-15-6573-2018, https://doi.org/10.5194/bg-15-6573-2018, 2018
Short summary
Short summary
During the OUTPACE cruise conducted in the oligotrophic to ultra-oligotrophic region of the western tropical South Pacific, two contrasted regions were sampled in terms of N2 fixation rates, primary production rates and nutrient availability. The aim of this work was to investigate the role of N2 fixation in the differences observed between the two contrasted areas by comparing two simulations only differing by the presence or not of N2 fixers using a 1-D biogeochemical–physical coupled model.
Karine Leblanc, Véronique Cornet, Peggy Rimmelin-Maury, Olivier Grosso, Sandra Hélias-Nunige, Camille Brunet, Hervé Claustre, Joséphine Ras, Nathalie Leblond, and Bernard Quéguiner
Biogeosciences, 15, 5595–5620, https://doi.org/10.5194/bg-15-5595-2018, https://doi.org/10.5194/bg-15-5595-2018, 2018
Short summary
Short summary
The Si biogeochemical cycle was studied during two oceanographic cruises in the tropical South Pacific in 2005 and 2015, between New Caledonia and the Chilean upwelling (8–34° S). Some of the lowest levels of biogenic silica stocks were found in the southern Pacific gyre, where Chlorophyll a concentrations are most depleted worldwide. Size-fractionated biogenic silica concentrations as well as Si kinetic uptake experiments revealed biological Si uptake by the picoplanktonic size fraction.
Thibaut Wagener, Nicolas Metzl, Mathieu Caffin, Jonathan Fin, Sandra Helias Nunige, Dominique Lefevre, Claire Lo Monaco, Gilles Rougier, and Thierry Moutin
Biogeosciences, 15, 5221–5236, https://doi.org/10.5194/bg-15-5221-2018, https://doi.org/10.5194/bg-15-5221-2018, 2018
Short summary
Short summary
The western tropical South Pacific was sampled along a longitudinal 4000 km transect (OUTPACE cruise) for the measurement of carbonate parameters (total alkalinity and total inorganic carbon) between the Melanesian Archipelago and the western part of the South Pacific gyre. This paper reports this new dataset and derived properties. We also estimate anthropogenic carbon distribution in the water column using the TrOCA method.
Marine Bretagnon, Aurélien Paulmier, Véronique Garçon, Boris Dewitte, Séréna Illig, Nathalie Leblond, Laurent Coppola, Fernando Campos, Federico Velazco, Christos Panagiotopoulos, Andreas Oschlies, J. Martin Hernandez-Ayon, Helmut Maske, Oscar Vergara, Ivonne Montes, Philippe Martinez, Edgardo Carrasco, Jacques Grelet, Olivier Desprez-De-Gesincourt, Christophe Maes, and Lionel Scouarnec
Biogeosciences, 15, 5093–5111, https://doi.org/10.5194/bg-15-5093-2018, https://doi.org/10.5194/bg-15-5093-2018, 2018
Short summary
Short summary
In oxygen minimum zone, the fate of the organic matter is a key question as the low oxygen condition would preserve the OM and thus enhance the biological carbon pump while the high microbial activity would foster the remineralisation and the greenhouse gases emission. To investigate this paradigm, sediment traps were deployed off Peru. We pointed out the influence of the oxygenation as well as the organic matter quantity and quality on the carbon transfer efficiency in the oxygen minimum zone.
Sophie Bonnet, Mathieu Caffin, Hugo Berthelot, Olivier Grosso, Mar Benavides, Sandra Helias-Nunige, Cécile Guieu, Marcus Stenegren, and Rachel Ann Foster
Biogeosciences, 15, 4215–4232, https://doi.org/10.5194/bg-15-4215-2018, https://doi.org/10.5194/bg-15-4215-2018, 2018
Dina Spungin, Natalia Belkin, Rachel A. Foster, Marcus Stenegren, Andrea Caputo, Mireille Pujo-Pay, Nathalie Leblond, Cécile Dupouy, Sophie Bonnet, and Ilana Berman-Frank
Biogeosciences, 15, 3893–3908, https://doi.org/10.5194/bg-15-3893-2018, https://doi.org/10.5194/bg-15-3893-2018, 2018
Short summary
Short summary
The way marine organisms die can determine the fate of organic matter (OM) in the ocean. We investigated whether a form of auto-induced programmed cell death (PCD) influenced phytoplankton mortality and fate of OM. Our results from high biomass blooms of the cyanobacterium Trichodesmium show evidence for PCD and high production of sticky carbon material termed transparent exopolymeric particles (TEP) that facilitates cellular aggregation and enhances the vertical flux of OM to depth.
Mathieu Caffin, Hugo Berthelot, Véronique Cornet-Barthaux, Aude Barani, and Sophie Bonnet
Biogeosciences, 15, 3795–3810, https://doi.org/10.5194/bg-15-3795-2018, https://doi.org/10.5194/bg-15-3795-2018, 2018
Mar Benavides, Katyanne M. Shoemaker, Pia H. Moisander, Jutta Niggemann, Thorsten Dittmar, Solange Duhamel, Olivier Grosso, Mireille Pujo-Pay, Sandra Hélias-Nunige, Alain Fumenia, and Sophie Bonnet
Biogeosciences, 15, 3107–3119, https://doi.org/10.5194/bg-15-3107-2018, https://doi.org/10.5194/bg-15-3107-2018, 2018
Short summary
Short summary
We measured N2 fixation rates and identified diazotrophic phylotypes in the mesopelagic layer along a transect spanning from New Caledonia to French Polynesia. N2 fixation rates were low but consistently detected across all depths and stations. A distinct diazotrophic phylotype dominated at 650 dbar, coinciding with the oxygenated Subantarctic Mode Water (SAMW) and suggesting that the distribution of aphotic diazotroph communities is to some extent controlled by water mass structure.
France Van Wambeke, Audrey Gimenez, Solange Duhamel, Cécile Dupouy, Dominique Lefevre, Mireille Pujo-Pay, and Thierry Moutin
Biogeosciences, 15, 2669–2689, https://doi.org/10.5194/bg-15-2669-2018, https://doi.org/10.5194/bg-15-2669-2018, 2018
Short summary
Short summary
The western tropical South Pacific Ocean has recently been shown to be a hotspot for biological nitrogen fixation. In this study, we examined the horizontal and vertical distribution of heterotrophic prokaryotic production alongside photosynthetic rates, nitrogen fixation rates and phosphate turnover times across the western tropical South Pacific Ocean, in order to relate these fluxes to bottom–up controls (related to nitrogen, phosphate and labile C availability).
Angela N. Knapp, Kelly M. McCabe, Olivier Grosso, Nathalie Leblond, Thierry Moutin, and Sophie Bonnet
Biogeosciences, 15, 2619–2628, https://doi.org/10.5194/bg-15-2619-2018, https://doi.org/10.5194/bg-15-2619-2018, 2018
Short summary
Short summary
The spatial distribution of biological N2 fixation fluxes to the ocean remains poorly constrained. Here we use nitrogen isotope budgets to identify significant N2 fixation inputs to the western tropical South Pacific (WTSP), where N2 fixation supports > 50 % of export production at stations proximal to iron sources. The significant N2 fixation inputs in the WTSP may offset nitrogen loss in the oxygen-deficient zones of the eastern tropical South Pacific.
Mathieu Caffin, Thierry Moutin, Rachel Ann Foster, Pascale Bouruet-Aubertot, Andrea Michelangelo Doglioli, Hugo Berthelot, Cécile Guieu, Olivier Grosso, Sandra Helias-Nunige, Nathalie Leblond, Audrey Gimenez, Anne Alexandra Petrenko, Alain de Verneil, and Sophie Bonnet
Biogeosciences, 15, 2565–2585, https://doi.org/10.5194/bg-15-2565-2018, https://doi.org/10.5194/bg-15-2565-2018, 2018
Short summary
Short summary
We performed N budgets to assess the role of N2 fixation on production and export in the western tropical South Pacific Ocean. We deployed a combination of techniques including high-sensitivity measurements of N input and sediment traps deployment. We demonstrated that N2 fixation was the major source of new N before atmospheric deposition and upward nitrate fluxes. It contributed significantly to organic matter export, indicating a high efficiency of this region to export carbon.
Louise Rousselet, Alain de Verneil, Andrea M. Doglioli, Anne A. Petrenko, Solange Duhamel, Christophe Maes, and Bruno Blanke
Biogeosciences, 15, 2411–2431, https://doi.org/10.5194/bg-15-2411-2018, https://doi.org/10.5194/bg-15-2411-2018, 2018
Short summary
Short summary
The patterns of the large- and fine-scale surface circulation on biogeochemical and biological distributions are examined in the western tropical South Pacific (WTSP) in the context of the OUTPACE oceanographic cruise. The combined use of in situ and satellite data allows for the identification of water mass transport pathways and fine-scale structures, such as fronts, that drive surface distribution of tracers and microbial community structures.
Alain de Verneil, Louise Rousselet, Andrea M. Doglioli, Anne A. Petrenko, Christophe Maes, Pascale Bouruet-Aubertot, and Thierry Moutin
Biogeosciences, 15, 2125–2147, https://doi.org/10.5194/bg-15-2125-2018, https://doi.org/10.5194/bg-15-2125-2018, 2018
Short summary
Short summary
Oceanographic campaigns to measure biogeochemical processes popularly deploy drifters with onboard incubations to stay in a single body of water. Here, we aggregate physical data taken during such a cruise, OUTPACE, to independently test in a new approach whether the drifter really stayed in what can be considered a single biological or chemical environment. This study concludes that future campaigns would benefit from similar data collection and analysis to validate their sampling strategy.
Vincent Taillandier, Thibaut Wagener, Fabrizio D'Ortenzio, Nicolas Mayot, Hervé Legoff, Joséphine Ras, Laurent Coppola, Orens Pasqueron de Fommervault, Catherine Schmechtig, Emilie Diamond, Henry Bittig, Dominique Lefevre, Edouard Leymarie, Antoine Poteau, and Louis Prieur
Earth Syst. Sci. Data, 10, 627–641, https://doi.org/10.5194/essd-10-627-2018, https://doi.org/10.5194/essd-10-627-2018, 2018
Short summary
Short summary
We report on data from an oceanographic cruise, covering western, central and eastern parts of the Mediterranean Sea. This cruise was fully dedicated to the maintenance and the metrological verification of a biogeochemical observing system based on a fleet of BGC-Argo floats.
Pierre Marrec, Gérald Grégori, Andrea M. Doglioli, Mathilde Dugenne, Alice Della Penna, Nagib Bhairy, Thierry Cariou, Sandra Hélias Nunige, Soumaya Lahbib, Gilles Rougier, Thibaut Wagener, and Melilotus Thyssen
Biogeosciences, 15, 1579–1606, https://doi.org/10.5194/bg-15-1579-2018, https://doi.org/10.5194/bg-15-1579-2018, 2018
Short summary
Short summary
The objective of this study was to better understand the variability of the phytoplankton community structure in small physical structures at the surface of the ocean. After identifying such a structure in the Mediterranean Sea, we deployed cutting-edge physical and biological sensors in order to observe at a high frequency the dynamics of this structure. From these observations we described the variations of the phytoplankton community structure and how the physics controls this variability.
Alain Fumenia, Thierry Moutin, Sophie Bonnet, Mar Benavides, Anne Petrenko, Sandra Helias Nunige, and Christophe Maes
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-557, https://doi.org/10.5194/bg-2017-557, 2018
Revised manuscript not accepted
Short summary
Short summary
The Melanesian archipelago waters between 160° E and 170° W are characterized by a significant N2 fixation rates and an excess of particulate organic nitrogen compared to the canonical ratio of Redfield and a positive N*. We hypothesize that the southern branch of the subtropical gyre is probably the main vector of excess nitrogen transport in the thermocline waters showing an influence of nitrogen fixation occurring in the western tropical in a large part of the South Pacific.
Alain de Verneil, Louise Rousselet, Andrea M. Doglioli, Anne A. Petrenko, and Thierry Moutin
Biogeosciences, 14, 3471–3486, https://doi.org/10.5194/bg-14-3471-2017, https://doi.org/10.5194/bg-14-3471-2017, 2017
Short summary
Short summary
A surface summer plankton bloom in the western tropical South Pacific was sampled during the Oligotrophy to UlTra-oligotrophy PACific Experiment (OUTPACE) cruise. We characterize the bloom's properties and the circulation responsible for its evolution. Nitrogen fixation helped sustain the bloom, and larger-scale flows, rather than the smaller ones, explain its movements. Future studies of blooms in this region can make use of these findings to track the horizontal export of plankton production.
Thierry Moutin, Andrea Michelangelo Doglioli, Alain de Verneil, and Sophie Bonnet
Biogeosciences, 14, 3207–3220, https://doi.org/10.5194/bg-14-3207-2017, https://doi.org/10.5194/bg-14-3207-2017, 2017
Short summary
Short summary
The overall goal of OUTPACE was to obtain a successful representation of the interactions between planktonic organisms and the cycle of biogenic elements in the western tropical South Pacific Ocean across trophic and N2 fixation gradients. The international OUTPACE cruise took place between 18 February and 3 April 2015 aboard the RV L’Atalante and involved 60 scientists. The transect covered ~4 000 km from the western part of the Melanesian archipelago to the western boundary of the gyre.
Audrey Gimenez, Melika Baklouti, Sophie Bonnet, and Thierry Moutin
Biogeosciences, 13, 5103–5120, https://doi.org/10.5194/bg-13-5103-2016, https://doi.org/10.5194/bg-13-5103-2016, 2016
Short summary
Short summary
In the context of the VAHINE mesocosm experiment in the Nouméa lagoon (New Caledonia), a 1-D vertical biogeochemical mechanistic model was used together with the in situ experiment to complement our comprehension of the planktonic ecosystem dynamics and the main biogeochemical carbon, nitrogen and phosphate fluxes. The model also showed the fate of fixed N2 by providing, over time, the proportion of diazotroph-derived nitrogen (DDN) in each compartment (mineral and organic) of the model.
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
Short summary
Short summary
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.
Ilana Berman-Frank, Dina Spungin, Eyal Rahav, France Van Wambeke, Kendra Turk-Kubo, and Thierry Moutin
Biogeosciences, 13, 3793–3805, https://doi.org/10.5194/bg-13-3793-2016, https://doi.org/10.5194/bg-13-3793-2016, 2016
Short summary
Short summary
In the marine environment, sticky sugar-containing gels, termed transparent exopolymeric particles (TEP), are produced from biological sources and physical and chemical processes. These compounds are essential vectors enhancing downward flow of organic matter and its storage at depth. Spatial and temporal dynamics of TEPs were followed for 23 days during the VAHINE mesocosm experiment that investigated the fate of nitrogen and carbon derived from organisms fixing atmospheric N2 (diazotrophs).
France Van Wambeke, Ulrike Pfreundt, Aude Barani, Hugo Berthelot, Thierry Moutin, Martine Rodier, Wolfgang R. Hess, and Sophie Bonnet
Biogeosciences, 13, 3187–3202, https://doi.org/10.5194/bg-13-3187-2016, https://doi.org/10.5194/bg-13-3187-2016, 2016
Short summary
Short summary
The phytoplankton is at the base of the plankton food web in large parts of oceanic "deserts" such as the South Pacific Ocean, where nitrogen sources limit activity. Mesocosms were fertilized with phosphorus to stimulate diazotrophy (atmospheric N2 fixation). Mostly diazotroph-derived nitrogen fuelled the heterotrophic bacterial community through indirect processes generating dissolved organic matter and detritus, such as mortality, lysis and grazing of both diazotrophs and non-diazotrophs.
Sophie Bonnet, Thierry Moutin, Martine Rodier, Jean-Michel Grisoni, Francis Louis, Eric Folcher, Bertrand Bourgeois, Jean-Michel Boré, and Armelle Renaud
Biogeosciences, 13, 2803–2814, https://doi.org/10.5194/bg-13-2803-2016, https://doi.org/10.5194/bg-13-2803-2016, 2016
Short summary
Short summary
e main goal of the VAHINE project was to study the fate of N2 fixation in the ocean. Three large-volume (~ 50 m3) mesocosms were deployed in a tropical oligotrophic ecosystem (the New Caledonia lagoon, south-eastern Pacific). This introductory paper describes the scientific objectives of the project in detail as well as the implementation plan: the mesocosm description and deployment, the selection of the study site, and the logistical and sampling strategy.
A. Guyennon, M. Baklouti, F. Diaz, J. Palmieri, J. Beuvier, C. Lebaupin-Brossier, T. Arsouze, K. Béranger, J.-C. Dutay, and T. Moutin
Biogeosciences, 12, 7025–7046, https://doi.org/10.5194/bg-12-7025-2015, https://doi.org/10.5194/bg-12-7025-2015, 2015
Short summary
Short summary
Dissolved organic carbon (DOC) has already been identified as a potentially significant source of carbon export in the Mediterranean Sea, though in situ export estimations are scarce. This work provides a thorough analysis at basin scale of carbon export with the coupled model NEMO-MED12/Eco3M-MED model. The seasonality and the processes of particulate and dissolved carbon production are also investigated. DOC export appears to be dominant in most regions, especially in the eastern basin.
H. Berthelot, T. Moutin, S. L'Helguen, K. Leblanc, S. Hélias, O. Grosso, N. Leblond, B. Charrière, and S. Bonnet
Biogeosciences, 12, 4099–4112, https://doi.org/10.5194/bg-12-4099-2015, https://doi.org/10.5194/bg-12-4099-2015, 2015
A. Talarmin, F. Van Wambeke, P. Lebaron, and T. Moutin
Biogeosciences, 12, 1237–1247, https://doi.org/10.5194/bg-12-1237-2015, https://doi.org/10.5194/bg-12-1237-2015, 2015
Short summary
Short summary
Along a transect in the warm nutrient-depleted Mediterranean Sea, we found that microorganisms shared phosphate resources by using different uptake strategies. Heterotrophic prokaryotes dominated phosphate uptake in the upper layers while cyanobacteria dominated uptake fluxes around the deep chlorophyll maximum depth. Synechococcus seemed well equipped to respond to pulses of phosphate, whereas Prochlorococcus and heterotrophs were more adapted to very low concentrations.
U. Christaki, D. Lefèvre, C. Georges, J. Colombet, P. Catala, C. Courties, T. Sime-Ngando, S. Blain, and I. Obernosterer
Biogeosciences, 11, 6739–6753, https://doi.org/10.5194/bg-11-6739-2014, https://doi.org/10.5194/bg-11-6739-2014, 2014
Short summary
Short summary
The concurrent investigation of several parameters has provided insight into two key roles of heterotrophic bacteria, and the microbial food web functioning, at the onset and late phase of the spring phytoplankton bloom induced by natural iron fertilization in the Southern Ocean.
K. Desboeufs, N. Leblond, T. Wagener, E. Bon Nguyen, and C. Guieu
Biogeosciences, 11, 5581–5594, https://doi.org/10.5194/bg-11-5581-2014, https://doi.org/10.5194/bg-11-5581-2014, 2014
Related subject area
Biogeochemistry: Open Ocean
Assessing the impact of CO2-equilibrated ocean alkalinity enhancement on microbial metabolic rates in an oligotrophic system
Phosphomonoesterase and phosphodiesterase activities in the eastern Mediterranean in two contrasting seasonal situations
Net primary production annual maxima in the North Atlantic projected to shift in the 21st century
Testing the influence of light on nitrite cycling in the eastern tropical North Pacific
Loss of nitrogen via anaerobic ammonium oxidation (anammox) in the California Current system during the late Quaternary
Technical note: Assessment of float pH data quality control methods – a case study in the subpolar northwest Atlantic Ocean
Effects of grain size and seawater salinity on magnesium hydroxide dissolution and secondary calcium carbonate precipitation kinetics: implications for ocean alkalinity enhancement
Linking northeastern North Pacific oxygen changes to upstream surface outcrop variations
Short-term response of Emiliania huxleyi growth and morphology to abrupt salinity stress
Underestimation of multi-decadal global O2 loss due to an optimal interpolation method
Reviews and syntheses: expanding the global coverage of gross primary production and net community production measurements using Biogeochemical-Argo floats
Characteristics of surface physical and biogeochemical parameters within mesoscale eddies in the Southern Ocean
Climatic Controls on Metabolic Constraints in the Ocean
Seasonal dynamics and annual budget of dissolved inorganic carbon in the northwestern Mediterranean deep-convection region
The fingerprint of climate variability on the surface ocean cycling of iron and its isotopes
Reconstructing the ocean's mesopelagic zone carbon budget: sensitivity and estimation of parameters associated with prokaryotic remineralization
Evolution of oxygen and stratification in the North Pacific Ocean in CMIP6 Earth System Models
Seasonal cycles of biogeochemical fluxes in the Scotia Sea, Southern Ocean: a stable isotope approach
Biological impact of ocean alkalinity enhancement of magnesium hydroxide on marine microalgae using bioassays simulating ship-based dispersion
Decadal changes of anthropogenic carbon in the Atlantic 1990–2010
Absence of photophysiological response to iron addition in autumn phytoplankton in the Antarctic sea-ice zone
Optimal parameters for the ocean's nutrient, carbon, and oxygen cycles compensate for circulation biases but replumb the biological pump
Importance of multiple sources of iron for the upper-ocean biogeochemistry over the northern Indian Ocean
Exploring the role of different data types and timescales in the quality of marine biogeochemical model calibration
All about nitrite: exploring nitrite sources and sinks in the eastern tropical North Pacific oxygen minimum zone
Fossil coccolith morphological attributes as a new proxy for deep ocean carbonate chemistry
Reconstructing ocean carbon storage with CMIP6 Earth system models and synthetic Argo observations
Using machine learning and Biogeochemical-Argo (BGC-Argo) floats to assess biogeochemical models and optimize observing system design
The representation of alkalinity and the carbonate pump from CMIP5 to CMIP6 Earth system models and implications for the carbon cycle
Model estimates of metazoans' contributions to the biological carbon pump
Tracing differences in iron supply to the Mid-Atlantic Ridge valley between hydrothermal vent sites: implications for the addition of iron to the deep ocean
Nitrite cycling in the primary nitrite maxima of the eastern tropical North Pacific
Hotspots and drivers of compound marine heatwaves and low net primary production extremes
Ecosystem impacts of marine heat waves in the northeast Pacific
Tracing the role of Arctic shelf processes in Si and N cycling and export through the Fram Strait: insights from combined silicon and nitrate isotopes
Controls on the relative abundances and rates of nitrifying microorganisms in the ocean
The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific
Influence of GEOTRACES data distribution and misfit function choice on objective parameter retrieval in a marine zinc cycle model
Physiological flexibility of phytoplankton impacts modelled chlorophyll and primary production across the North Pacific Ocean
Observation-constrained estimates of the global ocean carbon sink from Earth system models
Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise)
Controlling factors on the global distribution of a representative marine non-cyanobacterial diazotroph phylotype (Gamma A)
Summer trends and drivers of sea surface fCO2 and pH changes observed in the southern Indian Ocean over the last two decades (1998–2019)
Global nutrient cycling by commercially targeted marine fish
Major processes of the dissolved cobalt cycle in the North and equatorial Pacific Ocean
The impact of the South-East Madagascar Bloom on the oceanic CO2 sink
Nitrite regeneration in the oligotrophic Atlantic Ocean
Bridging the gaps between particulate backscattering measurements and modeled particulate organic carbon in the ocean
Biological production in two contrasted regions of the Mediterranean Sea during the oligotrophic period: an estimate based on the diel cycle of optical properties measured by BioGeoChemical-Argo profiling floats
Acidification of the Nordic Seas
Laura Marín-Samper, Javier Arístegui, Nauzet Hernández-Hernández, Joaquín Ortiz, Stephen D. Archer, Andrea Ludwig, and Ulf Riebesell
Biogeosciences, 21, 2859–2876, https://doi.org/10.5194/bg-21-2859-2024, https://doi.org/10.5194/bg-21-2859-2024, 2024
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Charly Andre Moras, Tyler Cyronak, Lennart Thomas Bach, Renaud Joannes-Boyau, and Kai Georg Schulz
EGUsphere, https://doi.org/10.5194/egusphere-2024-645, https://doi.org/10.5194/egusphere-2024-645, 2024
Short summary
Short summary
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 size dissolved faster, but calcium carbonate precipitated earlier, suggesting that medium grain size is optimum for both kinetics.
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
Short summary
Short summary
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.
Rosie M. Sheward, Christina Gebühr, Jörg Bollmann, and Jens O. Herrle
EGUsphere, https://doi.org/10.5194/egusphere-2024-349, https://doi.org/10.5194/egusphere-2024-349, 2024
Short summary
Short summary
How quickly do marine microorganisms respond to salinity stress? Our experiments with the calcifying marine plankton Emiliania huxleyi show that growth and cell morphology responded to salinity stress within as little as 24–48 hours, demonstrating that morphology and calcification is sensitive to salinity over a range of timescales. Our results have implications for understanding the short-term role of E. huxleyi in biogeochemical cycles and size-based paleoproxies for salinity.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Precious Mongwe, Matthew Long, Takamitsu Ito, Curtis Deutsch, and Yeray Santana-Falcón
EGUsphere, https://doi.org/10.5194/egusphere-2023-2822, https://doi.org/10.5194/egusphere-2023-2822, 2023
Short summary
Short summary
We use a collection of measurements that captures the physiological sensitivity of organisms to temperature and oxygen, and a model to investigate how natural climate variations and climate warming will impact the ability of marine heterotrophic marine organisms to support habitat in the future. We find that warming and the related loss of marine dissolved oxygen over the next several decades will reduce the volume of ocean habitat, and increasing vulnerability to temperature-oxygen extremes.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Lyuba Novi, Annalisa Bracco, Takamitsu Ito, and Yohei Takano
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-129, https://doi.org/10.5194/bg-2023-129, 2023
Revised manuscript accepted for BG
Short summary
Short summary
We explored the relationship between oxygen and stratification in the North Pacific Ocean, using a combination of data mining and machine learning. We used isopycnic potential vorticity (IPV) as an indicator to quantify ocean ventilation and we analyzed its predictability, a strong O2-IPV connection and predictability for IPV in the tropical Pacific. This open new routes to monitor ocean O2 through few observational sites co-located with more abundant IPV measurements in the tropical Pacific.
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
Short summary
Short summary
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.
Stephanie Delacroix, Tor Jensen Nystuen, Erik Höglund, and Andrew L. King
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-138, https://doi.org/10.5194/bg-2023-138, 2023
Revised manuscript accepted for BG
Short summary
Short summary
The addition of alkaline minerals into the oceans might reduce the excessive anthropogenic CO2 emissions. Magnesium hydroxide can be added in large amount because of its low seawater solubility without reaching harmful pH levels. The toxicity effect results of magnesium hydroxide, by simulating expected concentrations from a ships’ dispersion scenario, demonstrated low impacts on both sensitive and local assemblages of marine microalgae when compared to calcium hydroxide and sodium hydroxide.
Reiner Steinfeldt, Monika Rhein, and Dagmar Kieke
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-113, https://doi.org/10.5194/bg-2023-113, 2023
Revised manuscript accepted for BG
Short summary
Short summary
We calculate the amount of anthropogenic carbon (Cant) that is stored in the Atlantic Ocean for the years 1990, 2000, 2010. Cant is the carbon that is taken up by the ocean due to the rising atmospheric CO2 concentrations as a result of manmade CO2 emissions. However, most of the carbon in the ocean is natural. In order to determine the amount of Cant, we apply a special technique which is based on the observation of other manmade gases (e.g. CFCs).
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Rebecca Chmiel, Nathan Lanning, Allison Laubach, Jong-Mi Lee, Jessica Fitzsimmons, Mariko Hatta, William Jenkins, Phoebe Lam, Matthew McIlvin, Alessandro Tagliabue, and Mak Saito
Biogeosciences, 19, 2365–2395, https://doi.org/10.5194/bg-19-2365-2022, https://doi.org/10.5194/bg-19-2365-2022, 2022
Short summary
Short summary
Dissolved cobalt is present in trace amounts in seawater and is a necessary nutrient for marine microbes. On a transect from the Alaskan coast to Tahiti, we measured seawater concentrations of dissolved cobalt. Here, we describe several interesting features of the Pacific cobalt cycle including cobalt sources along the Alaskan coast and Hawaiian vents, deep-ocean particle formation, cobalt activity in low-oxygen regions, and how our samples compare to a global biogeochemical model’s predictions.
Nicolas Metzl, Claire Lo Monaco, Coraline Leseurre, Céline Ridame, Jonathan Fin, Claude Mignon, Marion Gehlen, and Thi Tuyet Trang Chau
Biogeosciences, 19, 1451–1468, https://doi.org/10.5194/bg-19-1451-2022, https://doi.org/10.5194/bg-19-1451-2022, 2022
Short summary
Short summary
During an oceanographic cruise conducted in January 2020 in the south-western Indian Ocean, we observed very low CO2 concentrations associated with a strong phytoplankton bloom that occurred south-east of Madagascar. This biological event led to a strong regional CO2 ocean sink not previously observed.
Darren R. Clark, Andrew P. Rees, Charissa M. Ferrera, Lisa Al-Moosawi, Paul J. Somerfield, Carolyn Harris, Graham D. Quartly, Stephen Goult, Glen Tarran, and Gennadi Lessin
Biogeosciences, 19, 1355–1376, https://doi.org/10.5194/bg-19-1355-2022, https://doi.org/10.5194/bg-19-1355-2022, 2022
Short summary
Short summary
Measurements of microbial processes were made in the sunlit open ocean during a research cruise (AMT19) between the UK and Chile. These help us to understand how microbial communities maintain the function of remote ecosystems. We find that the nitrogen cycling microbes which produce nitrite respond to changes in the environment. Our insights will aid the development of models that aim to replicate and ultimately project how marine environments may respond to ongoing climate change.
Martí Galí, Marcus Falls, Hervé Claustre, Olivier Aumont, and Raffaele Bernardello
Biogeosciences, 19, 1245–1275, https://doi.org/10.5194/bg-19-1245-2022, https://doi.org/10.5194/bg-19-1245-2022, 2022
Short summary
Short summary
Part of the organic matter produced by plankton in the upper ocean is exported to the deep ocean. This process, known as the biological carbon pump, is key for the regulation of atmospheric carbon dioxide and global climate. However, the dynamics of organic particles below the upper ocean layer are not well understood. Here we compared the measurements acquired by autonomous robots in the top 1000 m of the ocean to a numerical model, which can help improve future climate projections.
Marie Barbieux, Julia Uitz, Alexandre Mignot, Collin Roesler, Hervé Claustre, Bernard Gentili, Vincent Taillandier, Fabrizio D'Ortenzio, Hubert Loisel, Antoine Poteau, Edouard Leymarie, Christophe Penkerc'h, Catherine Schmechtig, and Annick Bricaud
Biogeosciences, 19, 1165–1194, https://doi.org/10.5194/bg-19-1165-2022, https://doi.org/10.5194/bg-19-1165-2022, 2022
Short summary
Short summary
This study assesses marine biological production in two Mediterranean systems representative of vast desert-like (oligotrophic) areas encountered in the global ocean. We use a novel approach based on non-intrusive high-frequency in situ measurements by two profiling robots, the BioGeoChemical-Argo (BGC-Argo) floats. Our results indicate substantial yet variable production rates and contribution to the whole water column of the subsurface layer, typically considered steady and non-productive.
Filippa Fransner, Friederike Fröb, Jerry Tjiputra, Nadine Goris, Siv K. Lauvset, Ingunn Skjelvan, Emil Jeansson, Abdirahman Omar, Melissa Chierici, Elizabeth Jones, Agneta Fransson, Sólveig R. Ólafsdóttir, Truls Johannessen, and Are Olsen
Biogeosciences, 19, 979–1012, https://doi.org/10.5194/bg-19-979-2022, https://doi.org/10.5194/bg-19-979-2022, 2022
Short summary
Short summary
Ocean acidification, a direct consequence of the CO2 release by human activities, is a serious threat to marine ecosystems. In this study, we conduct a detailed investigation of the acidification of the Nordic Seas, from 1850 to 2100, by using a large set of samples taken during research cruises together with numerical model simulations. We estimate the effects of changes in different environmental factors on the rate of acidification and its potential effects on cold-water corals.
Cited articles
Al-Mutairi, H. and Landry, M. R.: Active export of carbon and nitrogen at
station ALOHA by diel migrant zooplankton, Deep-Sea Res. Pt. II, 48,
2083–2103, https://doi.org/10.1016/S0967-0645(00)00174-0, 2001.
Aminot, A. and Kérouel, R.: Dosage automatique des nutriments dans les
eaux marines : méthodes en flux continu, Ed. Ifremer, Méthodes
d'analyse en milieu marin, 188 pp., 2007.
Antia, A. N.: Solubilization of particles in sediment traps: revising the
stoichiometry of mixed layer export, Biogeosciences, 2, 189–204,
https://doi.org/10.5194/bg-2-189-2005, 2005.
Banse, K.: Reflections about chance in my career, and on the top-down
regulated world, Annu. Rev. Mar. Sci., 5, 2.1–2.19, 2013.
Bates, N. R., Best, M. H. P., Neely, K., Garley, R., Dickson, A. G., and
Johnson, R. J.: Detecting anthropogenic carbon dioxide uptake and ocean
acidification in the North Atlantic Ocean, Biogeosciences, 9, 2509–2522,
https://doi.org/10.5194/bg-9-2509-2012, 2012.
Berthelot, H., Moutin, T., L'Helguen, S., Leblanc, K., Hélias, S.,
Grosso, O., Leblond, N., Charrière, B., and Bonnet, S.: Dinitrogen
fixation and dissolved organic nitrogen fueled primary production and
particulate export during the VAHINE mesocosm experiment (New Caledonia
lagoon), Biogeosciences, 12, 4099–4112,
https://doi.org/10.5194/bg-12-4099-2015, 2015.
Bianchi, D., Stock, C., Galbraith, E. D., and Sarmiento, J. L.: Diel vertical
migration: Ecological controls and impacts on the biological pump in a one
dimensional ocean model, Global Biogeochem. Cy., 27, 478–491,
https://doi.org/10.1002/gbc.20031, 2013.
Blain, S., Bonnet, S., and Guieu, C.: Dissolved iron distribution in the
tropical and sub tropical South Eastern Pacific, Biogeosciences, 5, 269–280,
https://doi.org/10.5194/bg-5-269-2008, 2008.
Bonnet, S., Caffin, M., Berthelot, H., and Moutin, T.: Hot spot of
N2 fixation in the western tropical South Pacific pleads for a
spatial decoupling between N2 fixation and denitrification, P.
Natl. Acad. Sci. USA, 114, E2800–E2801, https://doi.org/10.1073/pnas.1619514114, 2017.
Bonnet S., Caffin, M., Berthelot, H., Grosso, O., Guieu, C., and Foster, R.:
Contribution of dissolved and particulate fractions to the Hot Spot of
N2 fixation in the Western Tropical South Pacific Ocean (OUTPACE
cruise), Biogeosciences Discuss., in preparation, 2018.
Böttjer, D., Dore, J. E., Karl, D. M., Letelier, R. M., Mahaffey, C.,
Wilson, S. T., Zehr, J., and Church, M. J.: Temporal variability of nitrogen
fixation and particulate nitrogen export at Station ALOHA, Limnol. Oceanogr.,
62, 200–216, 2017.
Bouffard, D. and Boegman, L.: A diapycnal diffusivity model for stratified
environmental flows, Dynam. Atmos. Oceans, 61, 14—34, 2013.
Bouruet-Aubertot, P., Cuypers, Y., Doglioli, A., Caffin, M., Yohia, C., de
Verneil, A., Petrenko, A., Lefèvre, D., Le Goff, H., Rougier, G.,
Picheral, M., and Moutin, T.: Longitudinal contrast in Turbulence along a
∼ 19∘ S section in the Pacific and its consequences on
biogeochemical fluxes, Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-170, in
review, 2018.
Boutin, J., Quilfen, Y., Merlivat, L., and Piolle, J. F.: Global average of
air-sea CO2 transfer velocity from QuikSCAT scatterometer wind speeds, J.
Geophys. Res., 114, C04007, https://doi.org/10.1029/2007JC004168, 2009.
Buesseler, K. O., Antia, A. N., Chen, M., Fowler, S. W., Gardner, W. D.,
Gustafsson, O., Harada, K., Michaels, A. F., van der Loeff, M. R., Sarin, M.,
Steinberg, D. K., and Trull, T.: An assessment of the use of sediment traps
for estimating upper ocean particle fluxes, J. Mar. Res., 65, 345–416, 2007.
Brandes, J. A. and Devol, A. H.: A global marine fixed nitrogen isotopic
budget: Implications for Holocene nitrogen cycling, Global Biogeochem. Cy.,
16, 67.61–67.14, https://doi.org/10.1029/2001GB001856, 2002.
Broecker, W. S. and Henderson, G. M.: The sequence of events surrounding
Termination II and their implications for the cause of glacial-interglacial
CO2 changes, Paleoceanogr. Paleoclimatol, 13, 352–364, 1998.
Burd, A. B., Buchan, A., Church, M., Landry, M., McDonnell, A., Passow, U.,
Steinberg, D., and Benway, H.: Towards a transformative understanding of the
biology of the ocean's biological pump: Priorities for future research,
Report of the NSF Biology of the Biological Pump Workshop, 19–20 February
(Hyatt Place New Orleans, New Orleans, LA) 6 pp., https://doi.org/10.1575/1912/8263,
2016.
Caffin, M., Moutin, T., Foster, R. A., Bouruet-Aubertot, P., Doglioli, A. M.,
Berthelot, H., Guieu, C., Grosso, O., Helias-Nunige, S., Leblond, N.,
Gimenez, A., Petrenko, A. A., de Verneil, A., and Bonnet, S.: N2 fixation
as a dominant new N source in the western tropical South Pacific Ocean
(OUTPACE cruise), Biogeosciences, 15, 2565–2585,
https://doi.org/10.5194/bg-15-2565-2018, 2018.
Campbell, L., Carpenter, E. J., Montoya, J. P., Kustka, A. B., and Capone, D.
G.: Picoplankton community structure within and outside a Trichodesmium bloom
in the southwestern Pacific Ocean, Vie Milieu, 55, 185–195, 2005.
Carlson, C. A.: Production and removal processes, in: Biogeochemistry of
Marine Dissolved Organic Matter, edited by: Hansell, D. A. and Carlson, C.
A., 91–151, Academic, San Diego, Calif.,
https://doi.org/10.1016/B978-012323841-2/50006-3, 2002.
Capone, D. G. and Knapp, A. N.: Oceanography – A marine nitrogen cycle fix?,
Nature, 445, 159–160, 2007.
Cauwet, G.: HTCO method for dissolved organic carbon analysis in seawater:
influence of catalyst on blank estimation, Mar. Chem., 47, 55–64, 1994.
Cauwet, G.: Determination of dissolved organic carbon (DOC) and nitrogen
(DON) by high temperature combustion, in: Methods of seawater analysis,
edited by: Grashoff, K., Kremling, K., and Ehrhard, M., 3rd Ed., Wiley-VCH,
Weinheim, 407–420, 1999.
Codispoti, L. A.: An oceanic fixed nitrogen sink exceeding
400 Tg N a−1 vs the concept of homeostasis in the fixed-nitrogen
inventory, Biogeosciences, 4, 233–253,
https://doi.org/10.5194/bg-4-233-2007, 2007.
Codispoti, L. A., Brandes, J. A., Christensen, J. P., Devol, A. H., Naqvi, S.
W. A., Paerl, H. W., and Yoshinari, T.: The oceanic fixed nitrogen and
nitrous oxide budgets: Moving targets as we enter the anthropocene?, Sci.
Mar., 65, 85–105, 2001.
Copin-Montégut, G. and Avril, B.: Vertical distribution and temporal
variation of dissolved organic carbon in the North-Western Mediterranean Sea,
Deep-Sea Res., 40, 1963–1972, 1993.
de Boyer Montégut, C., Madec, G., Fischer, A. S., Lazar, A., and
Iudicone, D.: Mixed layer depth over the global ocean: an examination of
profile data and a profile-based climatology, J. Geophys. Res., 109, C12003,
https://doi.org/10.1029/2004JC002378, 2004.
Dekaezemacker, J., Bonnet, S., Grosso, O., Moutin, T., Bressac, M., and
Capone, D. G.: Evidence of active dinitrogen fixation in surface waters of
the eastern tropical South Pacific during El Nino and La Nina events and
evaluation of its potential nutrient controls, Global Biogeochem. Cy., 27,
768–779, https://doi.org/10.1002/gbc.20063, 2013.
Deutsch, C. and Weber, T.: Nutrient Ratios as a Tracer and Driver of Ocean
Biogeochemistry, Annu. Rev. Mar. Sci., 41, 4–113, 2012.
Deutsch, C., Gruber, N., Key, R., and Sarmiento, J. L.: Denitrification and
N2 fixation in the Pacific Ocean, Global Biogeochem. Cy., 15,
https://doi.org/10.1029/2000GB001291, 2001.
Deutsch, C., Sarmiento J. L., Sigman D. M., Grüber N., and Dunne J. P.:
Spatial coupling of nitrogen inputs and losses in the ocean, Nature, 445,
163–167, 2007.
de Verneil, A., Rousselet, L., Doglioli, A. M., Petrenko, A. A., Maes, C.,
Bouruet-Aubertot, P., and Moutin, T.: OUTPACE long duration stations:
physical variability, context of biogeochemical sampling, and evaluation of
sampling strategy, Biogeosciences, 15, 2125–2147,
https://doi.org/10.5194/bg-15-2125-2018, 2018.
Dickson, A. G.: An exact definition of total alkalinity and a procedure for
the estimation of alkalinity and total inorganic carbon from titration data,
Deep-Sea Res., 28A, 609–623, 1981.
DOE: Handbook of methods for the analysis of the various parameters of the
carbon dioxide system in sea water; version 2, edited by: Dickson, A. G. and
Goyet, C., ORNL/CDIAC-74, 1994.
Dore, J. E., Lukas, R., Sadler, D. W., and Karl, D. M.: Climate-driven
changes to the atmospheric CO2 sink in the subtropical North
Pacific Ocean, Nature, 424, 754-757, https://doi.org/10.1038/nature01885, 2003.
Duce, R. and Tindale, N.: Atmospheric transport of iron and its deposition in
the ocean, Limnol. Oceanogr., 36, 1715–1726, 1991.
Duhamel, S., Zeman, F., and Moutin, T.: A dual-labeling method for the
simultaneous measurement of dissolved inorganic carbon and phosphate uptake
by marine planktonic species, Limnol. Oceanogr.-Meth., 4, 416–425, 2006.
Dupouy, C., Neveux, J., Subramaniam, A., Mulholland, M. R., Montoya, J. P.,
Campbell, L., Carpenter, E. J., and Capone, D. G.: Satellite captures
Trichodesmium blooms in the southwestern tropical Pacific, EOS, 81, 13–16,
2000.
Dupouy, C., Benielli-Gary, D., Neveux, J., Dandonneau, Y., and Westberry, T.
K.: An algorithm for detecting Trichodesmium surface blooms in the
South Western Tropical Pacific, Biogeosciences, 8, 3631–3647,
https://doi.org/10.5194/bg-8-3631-2011, 2011.
Edmond, J. M.: High precision determination of totration alkalinity and the
total carbone dioxide contentof seawater by potentiometric titration, Deep
Sea Res., 17, 737–750, 1970.
Dutkiewicz, S., Ward, B. A., Monteiro, F., and Follows, M. J.:
Interconnection of nitrogen fixers and iron in the Pacific Ocean: Theory and
numerical simulations, Global Biogeochem. Cy., 26, GB1012,
https://doi.org/10.1029/2011GB004039, 2012.
Falkowski, P. G.: Evolution of the nitrogen cycle and its influence on the
biological sequestration of CO2 in the ocean, Nature, 387,
272–275, 1997.
Falkowski, P. G., Ziemann, D., Kolber, Z., and Bienfang, P. K.: Role of eddy
pumping in enhancing primary production in the ocean, Nature, 352, p. 55,
1991.
Falkowski, P. G., Barber, R. T., and Smetacek, V.: Biogeochemical Controls
and Feedbacks on Ocean Primary Production, Science, 281, 200–206, 1998.
Fitzsimmons, J. N., Boyle, E. A., and Jenkins, W. J.: Distal transport of
dissolved hydrothermal iron in the deep South Pacific Ocean, P. Natl. Acad.
Sci. USA, 25, 16654–16661, https://doi.org/10.1073/pnas.1418778111, 2014.
Fumenia, A., Moutin, T., Bonnet, S., Benavides, M., Petrenko, A., Helias
Nunige, S., and Maes, C.: Excess nitrogen as a marker of intense dinitrogen
fixation in the Western Tropical South Pacific Ocean: impact on the
thermocline waters of the South Pacific, Biogeosciences Discuss.,
https://doi.org/10.5194/bg-2017-557, in review, 2018.
Ganachaud, A., Cravatte, S., Sprintall, J., Germineaud, C., Marion Alberty,
M., Jeandel, C., Eldin, G., Metzl, N., Bonnet, S., Benavides, M., Heimburger,
L.-E., Lefèvre, J., Michael, S., Resing, J., Quéroué, F.,
Sarthou, G., Rodier, Berthelot, H., Baurand, F., Grelet, J., Hasegawa, T.,
Kessler, W., Kilepak, M., Lacan, F., Privat, E., Send, U., Van Beek, P.,
Souhaut, S., and Sonke, J. E.: The Solomon Sea: its circulation, chemistry,
geochemistry and biology explored during two oceanographic cruises, Elem.
Sci. Anth., 5, 33, https://doi.org/10.1525/elementa.221, 2017.
Garcia, H. E. and Gordon, L. I.: Oxygen solubility in seawater: Better
fitting equations, Limnol. Oceanogr., 37, 1307–1312,
https://doi.org/10.4319/lo.1992.37.6.1307, 1992.
Gattuso, J.-P. and Lavigne, H.: Technical Note: Approaches and software tools
to investigate the impact of ocean acidification, Biogeosciences, 6,
2121–2133, https://doi.org/10.5194/bg-6-2121-2009, 2009.
Gimenez, A., Baklouti, M., Bonnet, S., and Moutin, T.: Biogeochemical fluxes
and fate of diazotroph-derived nitrogen in the food web after a phosphate
enrichment: modeling of the VAHINE mesocosms experiment, Biogeosciences, 13,
5103–5120, https://doi.org/10.5194/bg-13-5103-2016, 2016.
Gimenez, A., Baklouti, M., and Moutin, T.: Diazotrophy as the main driver of
planktonic production and biogeochemical C, N, P cycles in the Western
Tropical South Pacific Ocean: results from a 1DV biogeochemical-physical
coupled model, Biogeosciences Discuss., https://doi.org/10.5194/bg-2018-162,
in review, 2018.
Grüber, N.: The dynamics of the marine nitrogen cycle and its influence
on atmospheric CO2, in: The ocean carbon cycle and climate, edited
by: Follows, M. and Oguz, T., Kluwer Academic, Dordrecht, 2004.
Grüber, N.: Elusive marine nitrogen fixation, P. Natl. Acad. Sci. USA,
113, 4246–4248, 2016.
Grüber, N. and Sarmiento, J. L.: Global patterns of marine nitrogen
fixation and denitrification, Global Biogeochem. Cy., 11, 235–266, 1997.
Guieu, C., Bonnet, S., Petrenko, A. A., Menkes, C., Chavagnac, V., Desboeufs,
K., Maes, C., and Moutin, T.: Iron from a submarine source impacts the
productive layer of the Western Tropical South Pacific (WTSP), Nature Sci.
Rep., in revision, 2018.
Hansell, D. A. and Carlson, C. A.: Localized refractory dissolved organic
carbon sinks in the deep ocean, Global Biogeochem. Cy., 27, 705–710,
https://doi.org/10.1002/gbc.20067, 2013.
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, 1999.
Jickells, T. D., Buitenhuis, E., Altieri, K., Baker, A. R., Capone, D. G.,
Duce, R. A., Dentener, F., Fennel, K., Kanakidou, M., LaRoche, J., Lee, K.,
Liss, P., Middelburg, J. J., Moore, J. K., Okin, G., Oschlies, A., Sarin, M.,
Seitzinger, S., Sharples, J., Singh, A., Suntharalingam, P., Uematsu, M., and
Zamora, L. M.: A reevaluation of the magnitude and impacts of anthropogenic
atmospheric nitrogen inputs on the ocean, Global Biogeochem. Cy., 31,
289–305, https://doi.org/10.1002/2016GB005586, 2017.
Kana, T. M., Darkangelo, C., Hunt, M. D., Oldham, J. B., Bennett, G. E., and
Cornwell, J. C.: Membrane Inlet Mass Spectrometer for Rapid High-Precision
Determination of N2, O2, and Ar in Environmental Water
Samples, Anal. Chem., 66, 4166–4170, https://doi.org/10.1021/ac00095a009, 1994.
Karl, D. M.: Microbially mediated transformations of phosphorus in the sea:
new views of an old cycle, Annu. Rev. Mar. Sci., 6, 279–337, 2014.
Karl, D. M., Christian, J. R., Dore, J. E., Hebel, D. V., Letelier, R. M.,
Tupas, L. M., and Winn, C. D.: Seasonal and interannual variability in
primary production and particle flux at station ALOHA, Deep-Sea Res. Pt. II,
43, 539–568, 1996.
Karl, D. M., Letelier, R. M, Tupas, L. M., Dore, J. E., Christian, J. R., and
Hebel, D. V.: The role of nitrogen fixation in biogeochemical cycling in the
subtropical North Pacific Ocean, Nature, 388, 533–538, 1997.
Karl, D. M., Church, M. J., Dore, J. E., Letelier, R. M., and Mahaffey, C.:
Predictable and efficient carbon sequestration in the North Pacific Ocean
supported by symbiotic nitrogen fixation, P. Natl. Acad. Sci. USA, 109,
1842–1849, https://doi.org/10.1073/pnas.1120312109, 2012.
Kim, D., Jeong, D. J., Kim, T. W., Noh, J. H., Kim, H. J., Choi, D. H., Kim,
E., and Jeon, D.: The reduction in the biomass of cyanobacterial N2
fixer and the biological pump in the Northwestern Pacific Ocean, Nature Sci.
Rep., 7, 41810, https://doi.org/10.1038/srep41810, 2017.
Knapp, A. N., Fawcett, S. E., Martínez-Garcia, A., Leblond, N., Moutin,
T., and Bonnet, S.: Nitrogen isotopic evidence for a shift from nitrate- to
diazotroph-fueled export production in the VAHINE mesocosm experiments,
Biogeosciences, 13, 4645–4657, https://doi.org/10.5194/bg-13-4645-2016,
2016.
Knapp, A. N., McCabe, K. M., Grosso, O., Leblond, N., Moutin, T., and Bonnet,
S.: Distribution and rates of nitrogen fixation in the western tropical South
Pacific Ocean constrained by nitrogen isotope budgets, Biogeosciences, 15,
2619–2628, https://doi.org/10.5194/bg-15-2619-2018, 2018.
Lachkar, Z., Lévy, M., and Smith, S.: Intensification and deepening of
the Arabian Sea oxygen minimum zone in response to increase in Indian monsoon
wind intensity, Biogeosciences, 15, 159–186,
https://doi.org/10.5194/bg-15-159-2018, 2018.
Landing, W. M. and Bruland, K. W.: The contrasting biogeochemistry of iron
and manganese in the Pacific Ocean, Geochim. Cosmochim. Ac., 51, 29–43,
1987.
Landolfi, A., Dietze, H., Koeve, W., and Oschlies, A.: Overlooked runaway
feedback in the marine nitrogen cycle: the vicious cycle, Biogeosciences, 10,
1351–1363, https://doi.org/10.5194/bg-10-1351-2013, 2013.
Landry, M. R., Selph, K. E., Taylor, A. G., Décima, M., Balch, W. M., and
Bidigare, R. R.: Phytoplankton growth, grazing and production balances in the
HNLC equatorial Pacific, Deep-Sea Res. Pt. II, 58, 524–535, 2011.
Langdon, C.: Determination of Dissolved Oxygen in Seawater by Winkler
Titration Using the Amperometric Technique, in: The GO-SHIP Repeat
Hydrography Manual: A Collection of Expert Reports and Guidelines, edited by:
Hood, E. M., Sabine, C. L., and Sloyan, B. M., IOCCP Report Number 14, ICPO
Publication Series Number 134, available at:
http://www.go-ship.org/HydroMan.html (last access: 8 May 2018), 2010.
Law, C. S., Woodward, E. M. S., Ellwood, M. J., Marriner, A., Bury, S. J.,
and Safi, K. A.: Response of surface nutrient inventories and nitrogen
fixation to a tropical cyclone in the southwest Pacific, Limnol. Oceanogr.,
56, 1372–1385, 2011.
Lévy, M., Ferrari, R., Franks, P. J. S., Martin, A. P., and Rivière,
P.: Bringing physics to life at the submesoscale, Geophys. Res. Lett., 39,
L14602, https://doi.org/10.1029/2012GL052756, 2012.
Levy, M., Jahn, O., Dutkiewicz, S., Follows, M. J., and d'Ovidio, F.: The
dynamical landscape of marine phytoplankton diversity, Royal. Soc. Interface,
12, 20150481, https://doi.org/10.1098/rsif.2015.0481, 2015.
Liss, P. S. and Merlivat, L.: Air-Sea Gas Exchange Rates: Introduction and
Synthesis, in: The Role of Air-Sea Exchange in Geochemical Cycling, edited
by: P., Buat-Ménard, NATO ASI Series (Series C: Mathematical and Physical
Sciences), vol. 185, Springer, Dordrecht,
https://doi.org/10.1007/978-94-009-4738-2_5, 1986.
Lueker, T. J., Dickson, A., and Keeling, C. D.: Ocean pCO2
calculated from dissolved inorganic carbon, alkalinity, and equations for K1
and K2: validation based on laboratory measurements of CO2 in gas
and seawater at equilibrium, Mar. Chem., 70, 105–119, 2000.
Mahaffey, C., Michaels, A. F., and Capone, D. G.: The conundrum of marine
N2 fixation, Am. J. Sci., 305, 546–595, 2005.
Marañón, E., Cermeno, P., and Perez, V.: Continuity in the
photosynthetic production of dissolved organic carbon from eutrophic to
oligotrophic waters, Mar. Ecol.-Prog. Ser., 299, 7–17, 2005.
Marty, J. C. and Chiavérini, J.: Seasonal and interannual variations in
phytoplankton production at DYFAMED time-series station, northwestern
Mediterranean Sea, Deep-Sea Res. Pt. II, 49, 2017–2030, 2002.
McDougall, T. J. and Barker, P. M.: Getting started with TEOS-10 and the
Gibbs Seawater (GSW) Oceanographic Toolbox, 28 pp., SCOR/IAPSO WG127, 2011.
McElroy, M. B.: Marine biological controls on atmospheric CO2 and
climate, Nature, 302, 328–329, 1983.
McMahon, K. W., McCarthy, M. D., Sherwood, O. A., Larsen, T., and Guilderson,
T. P.: Millennial-scale plankton regime shifts in the subtropical North
Pacific Ocean, Science, 350, 1530–1533, 2015.
Merlivat, L., Gonzalez Davila, M., Caniaux, G., Boutin, J., and Reverdin, G.:
Mesoscale and diel to monthly variability of CO2 and carbon fluxes
at the ocean surface in the northeastern Atlantic, J. Geophys. Res., 114,
C03010, https://doi.org/10.1029/2007JC004657, 2009.
Michaels, A. F., Karl, D. M., Capone, D. G.: Element stoichiometry, new
production and nitrogen fixation, Oceanography, 14, 68–77, 2001.
Millero, F. J.: The marine inorganic carbon cycle, Chem. Rev., 107, 308–341,
2007.
Minas, H. J., Minas, M., and Packard, T. T.: Productivity in upwelling areas
deduced from hydrographic and chemical fields, Limnol. Oceanogr., 31,
1182–1206, 1986.
Moisander, P. H., Zhang, R., Boyle, E. A., Hewson, I., Montoya, J. P., and
Zehr, J. P.: Analogous nutrient limitations in unicellular diazotrophs and
Prochlorococcus in the South Pacific Ocean, ISME J., 6, 733–744, 2012.
Monteiro, F. M., Dutkiewicz, S., and Follows, M. J.: Biogeographical controls
on the marine nitrogen fixers, Global Biogeochem. Cy., 25, GB2003,
https://doi.org/10.1029/2010GB003902, 2011.
Montoya, J. P., Voss, M., Kahler, P., and Capone, D. G.: A Simple,
High-Precision, High-Sensitivity Tracer Assay for N2 Fixation,
Appl. Environ. Microb., 62, 986–993, 1996.
Moore, C. M., Mills, M. M. M., Arrigo, K. R., Berman-Frank, I., Bopp, L.,
Boyd, P. W., Galbraith, E. D., Geider, R. J., Guieu, C., Jaccard, S. L.,
Jickells, T. D., La Roche, J., Lenton, T. M., Mahowald, N. M., Maranon, E.,
Marinov, I., Moore, J. K., Nakatsuka, T., Oschlies, A., Saito, M. A.,
Thingstad, T. F., Tsuda, A., and Ulloa, O.: Processes and patterns of oceanic
nutrient limitation, Nat. Geosci., 6, 701–710, 2013.
Moutin, T. and Raimbault, P.: Primary production, carbon export and nutrients
availability in western and eastern Mediterranean Sea in early summer 1996
(MINOS cruise), J. Marine Syst., 33–34, 273–288,
https://doi.org/10.1016/S0924-7963(02)00062-3, 2002.
Moutin, T., Raimbault, P., and Poggiale, J. C.: Production primaire dans les
eaux de surface de la Méditerranée occidentale: Calcul de la
production journalière, C. R. Acad. Sci. Paris, Sciences de la vie, 322,
651–659, 1999.
Moutin, T., Thingstad, T. F., Van Wambeke, F., Marie, D., Slawyk, G.,
Raimbault, P., and Claustre, H.: Does competition for nano-molar phosphate
supply explain the predominance of the cyanobacterium Synechococcus?, Limnol.
Oceanogr., 47, 1562–1567, 2002.
Moutin, T., Van Den Broeck, N., Beker, B., Dupouy, C., Rimmelin, P., and
LeBouteiller, A.: Phosphate availability controls Trichodesmium spp. biomass
in the SW Pacific ocean, Mar. Ecol.-Prog. Ser., 297, 15–21, 2005.
Moutin, T., Karl, D. M., Duhamel, S., Rimmelin, P., Raimbault, P., Van Mooy,
B. A. S., and Claustre, H.: Phosphate availability and the ultimate control
of new nitrogen input by nitrogen fixation in the tropical Pacific Ocean,
Biogeosciences, 5, 95–109, https://doi.org/10.5194/bg-5-95-2008, 2008.
Moutin, T., Van Wambeke, F., and Prieur, L.: Introduction to the
Biogeochemistry from the Oligotrophic to the Ultraoligotrophic Mediterranean
(BOUM) experiment, Biogeosciences, 9, 3817–3825,
https://doi.org/10.5194/bg-9-3817-2012, 2012.
Moutin, T., Doglioli, A. M., de Verneil, A., and Bonnet, S.: Preface: The
Oligotrophy to the UlTra-oligotrophy PACific Experiment (OUTPACE cruise, 18
February to 3 April 2015), Biogeosciences, 14, 3207–3220,
https://doi.org/10.5194/bg-14-3207-2017, 2017a.
Moutin, T., Bonnet, S., Richards, K., Capone, D. G., Marañón, E., and
Mémery, L. (Eds.): Interactions between planktonic organisms and
biogeochemical cycles across trophic and N2 fixation gradients in the
western tropical South Pacific Ocean: a multidisciplinary approach (OUTPACE
experiment), Biogeosciences,
https://www.biogeosciences.net/special_issue894.html, 2017b.
NOAA ESRL Global Monitoring Division: Atmospheric Carbon Dioxide Dry Air Mole
Fractions from quasi-continuous measurements at American Samoa, edited by:
Thoning, K. W., Kitzis, D. R., and Crotwell, A., National Oceanic and
Atmospheric Administration (NOAA), Earth System Research Laboratory (ESRL),
Global Monitoring Division (GMD): Boulder, Colorado, USA, Version 2014-08 at:
https://doi.org/10.7289/V51834DB, 2014.
Oschlies, A. and Garcon, V.: Eddy-induced enhancement of primary production
in a model of the North Atlantic Ocean, Nature, 394, 266–269, 1998.
Oudot, C., Gerard, R., Morin, P., and Gningue, I.: Precise shipboard
determination of dissolved-oxygen (Winkler Procedure) with a commercial
system, Limnol. Oceanogr., 33, 146–150, 1988.
Owens, W. B. and Millard Jr., R. C.: A new algorithm for CTD oxygen
calibration, J. Phys. Oceanogr., 15, 621–631, 1985.
Pujo-Pay, M. and Raimbault, P.: Improvement of the wet-oxidation procedure
for simultaneous determination of particulate organic nitrogen and phosphorus
collected on filters, Mar. Ecol.-Prog. Ser., 105, 203–207, 1994.
Pujo-Pay, M., Conan, P., Oriol, L., Cornet-Barthaux, V., Falco, C.,
Ghiglione, J.-F., Goyet, C., Moutin, T., and Prieur, L.: Integrated survey of
elemental stoichiometry (C, N, P) from the western to eastern Mediterranean
Sea, Biogeosciences, 8, 883–899, https://doi.org/10.5194/bg-8-883-2011,
2011.
Raven, J. A.: The iron and molybdenum use efficiencies of plant growth with
different energy, carbon and nitrogen source, New Phytol., 109, 279–287,
1988.
Redfield, A. C.: On the proportions of organic derivatives in sea water and
their relation to the composition of plankton, in: James Johnstone Memorial
Volume, edited by: Daniel, R. J., University Press, 176–192, 1934.
Rousselet, L., de Verneil, A., Doglioli, A. M., Petrenko, A. A., Duhamel, S.,
Maes, C., and Blanke, B.: Large- to submesoscale surface circulation and its
implications on biogeochemical/biological horizontal distributions during the
OUTPACE cruise (southwest Pacific), Biogeosciences, 15, 2411–2431,
https://doi.org/10.5194/bg-15-2411-2018, 2018.
Sarmiento, J. L. and Gruber, N.: Ocean Biogeochemical Dynamics, Princeton
University Press, Princeton, 503 pp., 2006.
Sharp, J. H.: Improved analysis for “particulate” organic carbon and
nitrogen from seawater, Limnol. Oceanogr., 19, 984–989, 1974.
Smeti, H., Pagano, M., Menkès, C., Lebourges Dhaussy, A., Hunt, B. P. V.,
Allain, V., Rodier, M., de Boissieu, F., Kestenare, E., and Sammari, C.:
Spatial and temporal variability of zooplankton off New Caledonia
(Southwestern Pacific) from acoustics and net measurements, J. Geophys.
Res.-Oceans, 120, 2676–2700, 2015.
Straub, M., Sigman, D. M., Ren, H., Martínez-García, A., Meckler,
A. N., Hain, M. P., and Haug, G. H.: Changes in North Atlantic nitrogen
fixation controlled by ocean circulation, Nature, 501, 7466,
https://doi.org/10.1038/nature12397, 2013.
Stukel, M. R., Aluwihare, L. I., Barbeau, K. A., Chekalyuk, A. M., Goericke,
R., Miller, A. J., Ohman, M. D., Ruacho, A., Song, H., Stephens, B., and
Landry, M. R.: Mesoscale ocean fronts enhance carbon export due to
gravitational sinking and subduction, P. Natl. Acad. Sci. USA, 114,
1252–1257, https://doi.org/10.1073/pnas.1609435114, 2017.
Sugimura, Y. and Suzuki, Y.: A high-temperature catalytic oxidation method
for the determination of non-volatile dissolved organic carbon in seawater by
direct injection of a liquid sample, Mar. Chem., 24, 105–131, 1988.
Tagliabue, A., Bopp, L., Dutay, J. C., Bowie, A. R., Chever, F.,
Jean-Baptiste, P., Bucciarelli, E., Lannuzel, D., Remenyi, T., Sarthou, G.,
Aumont, O., Gehlen, M., and Jeandel, C.: Hydrothermal iron contribution to
oceanic dissolved iron inventory, Nat. Geosci., 3, 252–256,
https://doi.org/10.1038/ngeo818, 2010.
Tagliabue, A., Bowie, A. R., Boyd, P. W., Buck, K. N., Johnson, K. S., and
Saito, M. A.: The integral role of iron in ocean biogeochemistry, Nature,
543, 51–59, https://doi.org/10.1038/nature21058, 2017.
Takahashi, T., Olafsson, J., Goddard, J., Chipman, D. W., and Sutherland, S.
C.: Seasonal variation of CO2 and nutrients in the high-latitude
surface oceans: a comparative study, Global Biogeochem. Cy., 7, 843–878,
1993.
Takahashi, T., Sutherland, S. C., Chipman, D. W., Goddard, J. G., Cheng Ho,
Newberger, T., Sweeney, C., and Munro, D. R.: Climatological Distributions of
pH, pCO2, Total CO2, Alkalinity, and CaCO3
Saturation in the Global Surface Ocean, and Temporal Changes at Selected
Locations, Mar. Chem., https://doi.org/10.1016/j.jmarchem.2014.06.004, 2014.
Taylor, B. W., Keep, C. F., Hall, Jr., R. O., Koch, B. J., Tronstad, L. M.,
Flecker, A. S., and Ulseth, A. J.: Improving the fluorometric ammonium
method: matrix effects, background fluorescence, and standard additions, J.
N. Am. Benthol. Soc., 26, 167–177, 2007.
Thingstad, T. F., Skjoldal, E. F., and Bohne, R. A.: Phosphorus cycling and
algal–bacterial competition in Sandsfjord, western Norway, Mar. Ecol.-Prog.
Ser., 99, 239–259, 1993.
Tyrell, T.: The relative influences of nitrogen and phosphorus on oceanic
primary production, Nature, 400, 525–531, 1999.
Valdés, V., Carlotti, F., Escribano, R., Donoso, K., Pagano, M., Molina,
V., and Fernandez, C.: Nitrogen and phosphorus recycling mediated by copepods
in Western Tropical South Pacific, Biogeosciences Discuss.,
https://doi.org/10.5194/bg-2017-563, in review, 2018.
Van Den Broeck, N., Moutin, T., Rodier, M., and Le Bouteiller, A.: Seasonal
variations of phosphate availability in the SW Pacific Ocean near New
Caledonia, Mar. Ecol.-Prog. Ser., 268, 1–12, 2004.
Van Wambeke, F., Christaki, U., Giannakourou, A., Moutin, T., and
Souvemerzoglou, K.: Longitudinal and vertical trends of bacterial limitation
by phosphorus and carbon in the Mediterranean Sea, Microbiol. Ecol., 43,
119–133, 2002.
Van Wambeke, F., Gimenez, A., Duhamel, S., Dupouy, C., Lefevre, D., Pujo-Pay,
M., and Moutin, T.: Dynamics and controls of heterotrophic prokaryotic
production in the western tropical South Pacific Ocean: links with
diazotrophic and photosynthetic activity, Biogeosciences, 15, 2669–2689,
https://doi.org/10.5194/bg-15-2669-2018, 2018.
Volk, T. and Hoffert, M. I.: The carbon cycle and atmospheric CO2:
natural variations Archean to present, Chapman conference papers, 1984,
edited by: Sundquist, E. T. and Broecker, W. S., American Geophysical Union,
Geophysical Monograph 32, 99–110, 1985.
Wagener, T., Guieu, C., Losno, R., Bonnet, S., and Mahowald, N. M.:
Revisiting atmospheric dust export to the Southern Hemisphere ocean:
Biogeochemical implications, Global Biogeochem. Cy., 22, 1–13,
https://doi.org/10.1029/2007GB002984, 2008.
Weber, T. and Deutsch, C.: Local versus basin-scale limitation of marine
nitrogen fixation, P. Natl. Acad. Sci. USA, 111, 8741–8746, 2014.
Wells, M. L., Vallis, G. K., and Silver, E. A.: Tectonic processes in Papua
New Guinea and past productivity in the eastern equatorial Pacific Ocean,
Nature, 398, 601–604, 1999.
Weiss, R. F. and Price, B. A.: Nitrous oxide solubility in water and
seawater, Mar. Chem., 8, 347–359, 1980.
Winkler, L. W.: Die Bestimmung des im Wasser gelosten Sauerstoffes, Ber.
Dtsch. Chem. Ges., 21, 2843–2853, 1888.
Wu, J., Sunda, W., Boyle, E. A., and Karl, D. M.: Phosphate depletion in the
western North Atlantic Ocean, Science, 289, 759–762, 2000.
Xie, X. H., Cuypers, Y., Bouruet-Aubertot, P., Ferron, B., Pichon, A.,
Lourenço, A., and Cortes, N.: Large-amplitude internal tides, solitary
waves, and turbulence in the central Bay of Biscay, Geophys. Res. Lett., 40,
2748–2754, 2013.
Yoshikawa, C., Makabe, A., Shiozaki, T., Toyoda, S., Yoshida, O., Furuya, K.,
and Yoshida, N.: Nitrogen isotope ratios of nitrate and N* anomalies in
the subtropical South Pacific, Geochem. Geophy. Geosy., 16, 1439–1448,
https://doi.org/10.1002/2014GC005678, 2015.
Zhang, X. and Dam, H. G.: Downward export of carbon by die1 migrant
mesozooplankton in the central equatorial Pacific, Deep-Sea Res. Pt. II, 44,
2191–2202, 1998.
Short summary
Surface waters of the western tropical South Pacific were sampled along a longitudinal 4000 km transect during the stratified period between the Melanesian Archipelago and the western part of the South Pacific gyre. We found a significant biological carbon pump sustained almost exclusively by N2 fixation and essentially controlled by phosphate availability in the iron-rich Melanesian Archipelago waters which appears to be a net sink for atmospheric CO2 while the gyre is in a quasi-steady state.
Surface waters of the western tropical South Pacific were sampled along a longitudinal 4000 km...
Altmetrics
Final-revised paper
Preprint