Articles | Volume 19, issue 5
07 Mar 2022
Research article | 07 Mar 2022
Nitrite regeneration in the oligotrophic Atlantic Ocean
Darren R. Clark et al.
Darren R. Clark, Claire E. Widdicombe, Andrew P. Rees, and E. Malcolm S. Woodward
Biogeosciences, 13, 2873–2888,Short summary
Based in the Mauritanian upwelling system, the article describes a Lagrangian study of biogeochemical processes within a freshly upwelled body of water as it advects offshore. We report rates of primary production, nitrogen assimilation, and regeneration and describe how these processes relate to the dynamics of the upwelling regime. This system is perhaps the least studied of the four major eastern boundary upwelling systems and so these measurements provide important new insights.
D. R. Clark, I. J. Brown, A. P. Rees, P. J. Somerfield, and P. I. Miller
Biogeosciences, 11, 4985–5005,
Guillaume Dodet, Jean-François Piolle, Yves Quilfen, Saleh Abdalla, Mickaël Accensi, Fabrice Ardhuin, Ellis Ash, Jean-Raymond Bidlot, Christine Gommenginger, Gwendal Marechal, Marcello Passaro, Graham Quartly, Justin Stopa, Ben Timmermans, Ian Young, Paolo Cipollini, and Craig Donlon
Earth Syst. Sci. Data, 12, 1929–1951,Short summary
Sea state data are of major importance for climate studies, marine engineering, safety at sea and coastal management. However, long-term sea state datasets are sparse and not always consistent. The CCI is a program of the European Space Agency, whose objective is to realize the full potential of global Earth Observation archives in order to contribute to the ECV database. This paper presents the implementation of the first release of the Sea State CCI dataset.
Thomas Holding, Ian G. Ashton, Jamie D. Shutler, Peter E. Land, Philip D. Nightingale, Andrew P. Rees, Ian Brown, Jean-Francois Piolle, Annette Kock, Hermann W. Bange, David K. Woolf, Lonneke Goddijn-Murphy, Ryan Pereira, Frederic Paul, Fanny Girard-Ardhuin, Bertrand Chapron, Gregor Rehder, Fabrice Ardhuin, and Craig J. Donlon
Ocean Sci., 15, 1707–1728,Short summary
FluxEngine is an open-source software toolbox designed to allow for the easy and accurate calculation of air–sea gas fluxes. This article describes new functionality and capabilities, which include the ability to calculate fluxes for nitrous oxide and methane, optimisation for running FluxEngine on a stand-alone desktop computer, and extensive new features to support the in situ measurement community. Four research case studies are used to demonstrate these new features.
Mingxi Yang, Thomas G. Bell, Ian J. Brown, James R. Fishwick, Vassilis Kitidis, Philip D. Nightingale, Andrew P. Rees, and Timothy J. Smyth
Biogeosciences, 16, 961–978,Short summary
We quantify the emissions and uptake of the greenhouse gases carbon dioxide and methane from the coastal seas of the UK over 1 year using the state-of-the-art eddy covariance technique. Our measurements show how these air–sea fluxes vary twice a day (tidal), diurnally (circadian) and seasonally. We also estimate the air–sea gas transfer velocity, which is essential for modelling and predicting coastal air-sea exchange.
Chris J. Daniels, Alex J. Poulton, William M. Balch, Emilio Marañón, Tim Adey, Bruce C. Bowler, Pedro Cermeño, Anastasia Charalampopoulou, David W. Crawford, Dave Drapeau, Yuanyuan Feng, Ana Fernández, Emilio Fernández, Glaucia M. Fragoso, Natalia González, Lisa M. Graziano, Rachel Heslop, Patrick M. Holligan, Jason Hopkins, María Huete-Ortega, David A. Hutchins, Phoebe J. Lam, Michael S. Lipsen, Daffne C. López-Sandoval, Socratis Loucaides, Adrian Marchetti, Kyle M. J. Mayers, Andrew P. Rees, Cristina Sobrino, Eithne Tynan, and Toby Tyrrell
Earth Syst. Sci. Data, 10, 1859–1876,Short summary
Calcifying marine algae (coccolithophores) are key to oceanic biogeochemical processes, such as calcium carbonate production and export. We compile a global database of calcium carbonate production from field samples (n = 2756), alongside primary production rates and coccolithophore abundance. Basic statistical analysis highlights global distribution, average surface and integrated rates, patterns with depth and the importance of considering cell-normalised rates as a simple physiological index.
Samuel T. Wilson, Hermann W. Bange, Damian L. Arévalo-Martínez, Jonathan Barnes, Alberto V. Borges, Ian Brown, John L. Bullister, Macarena Burgos, David W. Capelle, Michael Casso, Mercedes de la Paz, Laura Farías, Lindsay Fenwick, Sara Ferrón, Gerardo Garcia, Michael Glockzin, David M. Karl, Annette Kock, Sarah Laperriere, Cliff S. Law, Cara C. Manning, Andrew Marriner, Jukka-Pekka Myllykangas, John W. Pohlman, Andrew P. Rees, Alyson E. Santoro, Philippe D. Tortell, Robert C. Upstill-Goddard, David P. Wisegarver, Gui-Ling Zhang, and Gregor Rehder
Biogeosciences, 15, 5891–5907,Short summary
To determine the variability between independent measurements of dissolved methane and nitrous oxide, seawater samples were analyzed by multiple laboratories. The results revealed the influences of the different parts of the analytical process, from the initial sample collection to the calculation of the final concentrations. Recommendations are made to improve dissolved methane and nitrous oxide measurements to help preclude future analytical discrepancies between laboratories.
Graham D. Quartly, Eero Rinne, Marcello Passaro, Ole B. Andersen, Salvatore Dinardo, Sara Fleury, Kevin Guerreiro, Amandine Guillot, Stefan Hendricks, Andrey A. Kurekin, Felix L. Müller, Robert Ricker, Henriette Skourup, and Michel Tsamados
The Cryosphere Discuss.,
Revised manuscript not acceptedShort summary
Radar altimetry is a high-precision technique for measuring sea level and sea ice thickness from space, which are important for monitoring ocean circulation, sea level rise and changes in the Arctic ice cover. This paper reviews the processing techniques needed to best extract the information from complicated radar echoes, and considers the likely developments in the coming decade.
Jean-François Legeais, Michaël Ablain, Lionel Zawadzki, Hao Zuo, Johnny A. Johannessen, Martin G. Scharffenberg, Luciana Fenoglio-Marc, M. Joana Fernandes, Ole Baltazar Andersen, Sergei Rudenko, Paolo Cipollini, Graham D. Quartly, Marcello Passaro, Anny Cazenave, and Jérôme Benveniste
Earth Syst. Sci. Data, 10, 281–301,Short summary
Sea level is one of the best indicators of climate change and has been listed as one of the essential climate variables. Sea level measurements have been provided by satellite altimetry for 25 years, and the Climate Change Initiative (CCI) program of the European Space Agency has given the opportunity to provide a long-term, homogeneous and accurate sea level record. It will help scientists to better understand climate change and its variability.
Graham D. Quartly, Jean-François Legeais, Michaël Ablain, Lionel Zawadzki, M. Joana Fernandes, Sergei Rudenko, Loren Carrère, Pablo Nilo García, Paolo Cipollini, Ole B. Andersen, Jean-Christophe Poisson, Sabrina Mbajon Njiche, Anny Cazenave, and Jérôme Benveniste
Earth Syst. Sci. Data, 9, 557–572,Short summary
We have produced an improved monthly record of mean sea level for 1993–2015. It is developed by careful processing of the records from nine satellite altimeter missions, making use of the best available orbits, instrumental corrections and geophysical corrections. This paper details the selection process and the processing method. The data are suitable for investigation of sea level changes at scales from seasonal to long-term sea level rise, including interannual variations due to El Niño.
Darren R. Clark, Claire E. Widdicombe, Andrew P. Rees, and E. Malcolm S. Woodward
Biogeosciences, 13, 2873–2888,Short summary
Based in the Mauritanian upwelling system, the article describes a Lagrangian study of biogeochemical processes within a freshly upwelled body of water as it advects offshore. We report rates of primary production, nitrogen assimilation, and regeneration and describe how these processes relate to the dynamics of the upwelling regime. This system is perhaps the least studied of the four major eastern boundary upwelling systems and so these measurements provide important new insights.
Momme Butenschön, James Clark, John N. Aldridge, Julian Icarus Allen, Yuri Artioli, Jeremy Blackford, Jorn Bruggeman, Pierre Cazenave, Stefano Ciavatta, Susan Kay, Gennadi Lessin, Sonja van Leeuwen, Johan van der Molen, Lee de Mora, Luca Polimene, Sevrine Sailley, Nicholas Stephens, and Ricardo Torres
Geosci. Model Dev., 9, 1293–1339,Short summary
ERSEM 15.06 is a model for marine biogeochemistry and the lower trophic levels of the marine food web. It comprises a pelagic and benthic sub-model including the microbial food web and the major biogeochemical cycles of carbon, nitrogen, phosphorus, silicate, and iron using dynamic stochiometry. Further features include modules for the carbonate system and calcification. We present full mathematical descriptions of all elements along with examples at various scales up to 3-D applications.
D. R. Clark, I. J. Brown, A. P. Rees, P. J. Somerfield, and P. I. Miller
Biogeosciences, 11, 4985–5005,
T. J. Browning, H. A. Bouman, C. M. Moore, C. Schlosser, G. A. Tarran, E. M. S. Woodward, and G. M. Henderson
Biogeosciences, 11, 463–479,
Related subject area
Biogeochemistry: Open OceanControlling 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 fishMajor processes of the dissolved cobalt cycle in the North and equatorial Pacific OceanThe impact of the South-East Madagascar Bloom on the oceanic CO2 sinkBridging the gaps between particulate backscattering measurements and modeled particulate organic carbon in the oceanBiological 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 floatsAcidification of the Nordic SeasReconstruction of global surface ocean pCO2 using region-specific predictors based on a stepwise FFNN regression algorithmBiogeochemical controls on ammonium accumulation in the surface layer of the Southern OceanOxygen export to the deep ocean following Labrador Sea Water formationN2 fixation in the Mediterranean Sea related to the composition of the diazotrophic community and impact of dust under present and future environmental conditionsDissolution of a submarine carbonate platform by a submerged lake of acidic seawaterSeasonal flux patterns and carbon transport from low-oxygen eddies at the Cape Verde Ocean Observatory: lessons learned from a time series sediment trap study (2009–2016)Subsurface iron accumulation and rapid aluminum removal in the Mediterranean following African dust depositionLong-distance particle transport to the central Ionian SeaDeep chlorophyll maximum and nutricline in the Mediterranean Sea: emerging properties from a multi-platform assimilated biogeochemical model experimentPhosphorus cycling in the upper waters of the Mediterranean Sea (PEACETIME cruise): relative contribution of external and internal sourcesFast local warming is the main driver of recent deoxygenation in the northern Arabian SeaInfluence of atmospheric deposition on biogeochemical cycles in an oligotrophic ocean systemImpact of dust addition on the metabolism of Mediterranean plankton communities and carbon export under present and future conditions of pH and temperatureComparing CLE-AdCSV applications using SA and TAC to determine the Fe-binding characteristics of model ligands in seawaterImpact of dust addition on Mediterranean plankton communities under present and future conditions of pH and temperature: an experimental overviewReviews and syntheses: Trends in primary production in the Bay of Bengal – is it at a tipping point?Incorporating the stable carbon isotope 13C in the ocean biogeochemical component of the Max Planck Institute Earth System ModelSeasonal cycling of zinc and cobalt in the south-eastern Atlantic along the GEOTRACES GA10 sectionCarbon export and fate beneath a dynamic upwelled filament off the California coastContrasted release of insoluble elements (Fe, Al, rare earth elements, Th, Pa) after dust deposition in seawater: a tank experiment approachOn the barium–oxygen consumption relationship in the Mediterranean Sea: implications for mesopelagic marine snow remineralizationCompound high-temperature and low-chlorophyll extremes in the ocean over the satellite periodCan machine learning extract the mechanisms controlling phytoplankton growth from large-scale observations? – A proof-of-concept studyEarly winter barium excess in the Southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise)Reviews and syntheses: The biogeochemical cycle of silicon in the modern oceanOxygen budget of the north-western Mediterranean deep- convection regionCross-basin differences in the nutrient assimilation characteristics of induced phytoplankton blooms in the subtropical Pacific watersDynamics of the deep chlorophyll maximum in the Black Sea as depicted by BGC-Argo floatsNitrate assimilation and regeneration in the Barents Sea: insights from nitrate isotopesAssimilating synthetic Biogeochemical-Argo and ocean colour observations into a global ocean model to inform observing system designSouthern Ocean Biogeochemical Argo detect under-ice phytoplankton growth before sea ice retreatA new intermittent regime of convective ventilation threatens the Black Sea oxygenation statusReviews and syntheses: Present, past, and future of the oxygen minimum zone in the northern Indian OceanParticulate rare earth element behavior in the North Atlantic (GEOVIDE cruise)Elevated sources of cobalt in the Arctic OceanIncrease in ocean acidity variability and extremes under increasing atmospheric CO2Can ocean community production and respiration be determined by measuring high-frequency oxygen profiles from autonomous floats?Assessing the value of biogeochemical Argo profiles versus ocean color observations for biogeochemical model optimization in the Gulf of MexicoThe Southern Annular Mode (SAM) influences phytoplankton communities in the seasonal ice zone of the Southern OceanProfiling float observation of thermohaline staircases in the western Mediterranean Sea and impact on nutrient fluxesOcean carbonate system variability in the North Atlantic Subpolar surface water (1993–2017)Characterizing the surface microlayer in the Mediterranean Sea: trace metal concentrations and microbial plankton abundance
Zhibo Shao and Ya-Wei Luo
Biogeosciences, 19, 2939–2952,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,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,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,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,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.
Martí Galí, Marcus Falls, Hervé Claustre, Olivier Aumont, and Raffaele Bernardello
Biogeosciences, 19, 1245–1275,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,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,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.
Guorong Zhong, Xuegang Li, Jinming Song, Baoxiao Qu, Fan Wang, Yanjun Wang, Bin Zhang, Xiaoxia Sun, Wuchang Zhang, Zhenyan Wang, Jun Ma, Huamao Yuan, and Liqin Duan
Biogeosciences, 19, 845–859,Short summary
A predictor selection algorithm was constructed to decrease the predicting error in the surface ocean partial pressure of CO2 (pCO2) mapping by finding better combinations of pCO2 predictors in different regions. Compared with previous research using the same combination of predictors in all regions, using different predictors selected by the algorithm in different regions can effectively decrease pCO2 predicting errors.
Shantelle Smith, Katye E. Altieri, Mhlangabezi Mdutyana, David R. Walker, Ruan G. Parrott, Sedick Gallie, Kurt A. M. Spence, Jessica M. Burger, and Sarah E. Fawcett
Biogeosciences, 19, 715–741,Short summary
Ammonium is a crucial yet poorly understood component of the Southern Ocean nitrogen cycle. We attribute our finding of consistently high ammonium concentrations in the winter mixed layer to limited ammonium consumption and sustained ammonium production, conditions under which the Southern Ocean becomes a source of carbon dioxide to the atmosphere. From similar data collected over an annual cycle, we propose a seasonal cycle for ammonium in shallow polar waters – a first for the Southern Ocean.
Jannes Koelling, Dariia Atamanchuk, Johannes Karstensen, Patricia Handmann, and Douglas W. R. Wallace
Biogeosciences, 19, 437–454,Short summary
In this study, we investigate oxygen variability in the deep western boundary current in the Labrador Sea from multiyear moored records. We estimate that about half of the oxygen taken up in the interior Labrador Sea by air–sea gas exchange during deep water formation is exported southward the same year. Our results underline the complexity of the oxygen uptake and export in the Labrador Sea and highlight the important role this region plays in supplying oxygen to the deep ocean.
Céline Ridame, Julie Dinasquet, Søren Hallstrøm, Estelle Bigeard, Lasse Riemann, France Van Wambeke, Matthieu Bressac, Elvira Pulido-Villena, Vincent Taillandier, Fréderic Gazeau, Antonio Tovar-Sanchez, Anne-Claire Baudoux, and Cécile Guieu
Biogeosciences, 19, 415–435,Short summary
We show that in the Mediterranean Sea spatial variability in N2 fixation is related to the diazotrophic community composition reflecting different nutrient requirements among species. Nutrient supply by Saharan dust is of great importance to diazotrophs, as shown by the strong stimulation of N2 fixation after a simulated dust event under present and future climate conditions; the magnitude of stimulation depends on the degree of limitation related to the diazotrophic community composition.
Matthew P. Humphreys, Erik H. Meesters, Henk de Haas, Szabina Karancz, Louise Delaigue, Karel Bakker, Gerard Duineveld, Siham de Goeyse, Andreas F. Haas, Furu Mienis, Sharyn Ossebaar, and Fleur C. van Duyl
Biogeosciences, 19, 347–358,Short summary
A series of submarine sinkholes were recently discovered on Luymes Bank, part of Saba Bank, a carbonate platform in the Caribbean Netherlands. Here, we investigate the waters inside these sinkholes for the first time. One of the sinkholes contained a body of dense, low-oxygen and low-pH water, which we call the
acid lake. We use measurements of seawater chemistry to work out what processes were responsible for forming the acid lake and discuss the consequences for the carbonate platform.
Gerhard Fischer, Oscar E. Romero, Johannes Karstensen, Karl-Heinz Baumann, Nasrollah Moradi, Morten Iversen, Götz Ruhland, Marco Klann, and Arne Körtzinger
Biogeosciences, 18, 6479–6500,Short summary
Low-oxygen eddies in the eastern subtropical North Atlantic can form an oasis for phytoplankton growth. Here we report on particle flux dynamics at the oligotrophic Cape Verde Ocean Observatory. We observed consistent flux patterns during the passages of low-oxygen eddies. We found distinct flux peaks in late winter, clearly exceeding background fluxes. Our findings suggest that the low-oxygen eddies sequester higher organic carbon than expected for oligotrophic settings.
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,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.
Léo Berline, Andrea Michelangelo Doglioli, Anne Petrenko, Stéphanie Barrillon, Boris Espinasse, Frederic A. C. Le Moigne, François Simon-Bot, Melilotus Thyssen, and François Carlotti
Biogeosciences, 18, 6377–6392,Short summary
While the Ionian Sea is considered a nutrient-depleted and low-phytoplankton biomass area, it is a crossroad for water mass circulation. In the central Ionian Sea, we observed a strong contrast in particle distribution across a ~100 km long transect. Using remote sensing and Lagrangian simulations, we suggest that this contrast finds its origin in the long-distance transport of particles from the north, west and east of the Ionian Sea, where phytoplankton production was more intense.
Anna Teruzzi, Giorgio Bolzon, Laura Feudale, and Gianpiero Cossarini
Biogeosciences, 18, 6147–6166,Short summary
During summer, maxima of phytoplankton chlorophyll concentration (DCM) occur in the subsurface of the Mediterranean Sea and can play a relevant role in carbon sequestration into the ocean interior. A numerical model based on in situ and satellite observations provides insights into the range of DCM conditions across the relatively small Mediterranean Sea and shows a western DCM that is 25 % shallower and with a higher phytoplankton chlorophyll concentration than in the eastern Mediterranean.
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,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.
Zouhair Lachkar, Michael Mehari, Muchamad Al Azhar, Marina Lévy, and Shafer Smith
Biogeosciences, 18, 5831–5849,Short summary
This study documents and quantifies a significant recent oxygen decline in the upper layers of the Arabian Sea and explores its drivers. Using a modeling approach we show that the fast local warming of sea surface is the main factor causing this oxygen drop. Concomitant summer monsoon intensification contributes to this trend, although to a lesser extent. These changes exacerbate oxygen depletion in the subsurface, threatening marine habitats and altering the local biogeochemistry.
France Van Wambeke, Vincent Taillandier, Karine Desboeufs, Elvira Pulido-Villena, Julie Dinasquet, Anja Engel, Emilio Marañón, Céline Ridame, and Cécile Guieu
Biogeosciences, 18, 5699–5717,Short summary
Simultaneous in situ measurements of (dry and wet) atmospheric deposition and biogeochemical stocks and fluxes in the sunlit waters of the open Mediterranean Sea revealed complex physical and biological processes occurring within the mixed layer. Nitrogen (N) budgets were computed to compare the sources and sinks of N in the mixed layer. The transitory effect observed after a wet dust deposition impacted the microbial food web down to the deep chlorophyll maximum.
Frédéric Gazeau, France Van Wambeke, Emilio Marañón, Maria Pérez-Lorenzo, Samir Alliouane, Christian Stolpe, Thierry Blasco, Nathalie Leblond, Birthe Zäncker, Anja Engel, Barbara Marie, Julie Dinasquet, and Cécile Guieu
Biogeosciences, 18, 5423–5446,Short summary
Our study shows that the impact of dust deposition on primary production depends on the initial composition and metabolic state of the tested community and is constrained by the amount of nutrients added, to sustain both the fast response of heterotrophic prokaryotes and the delayed one of phytoplankton. Under future environmental conditions, heterotrophic metabolism will be more impacted than primary production, therefore reducing the capacity of surface waters to sequester anthropogenic CO2.
Loes J. A. Gerringa, Martha Gledhill, Indah Ardiningsih, Niels Muntjewerf, and Luis M. Laglera
Biogeosciences, 18, 5265–5289,Short summary
For 3 decades, competitive ligand exchange–adsorptive cathodic stripping voltammetry was used to estimate the Fe-binding capacity of organic matter in seawater. In this paper the performance of the competing ligands is compared through the analysis of a series of model ligands. The main finding of this paper is that the determined speciation parameters are not independent of the application, making interpretation of Fe speciation data more complex than it was thought before.
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,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.
Carolin R. Löscher
Biogeosciences, 18, 4953–4963,Short summary
The Bay of Bengal (BoB) is classically seen as an ocean region with low primary production, which has been predicted to decrease even further. Here, the importance of such a trend is used to explore what could happen to the BoB's low-oxygen core waters if primary production decreases. Lower biological production leads to less oxygen loss in deeper waters by respiration; thus it could be that oxygen will not further decrease and the BoB will not become anoxic, different to other low-oxygen areas.
Bo Liu, Katharina D. Six, and Tatiana Ilyina
Biogeosciences, 18, 4389–4429,Short summary
We incorporate a new representation of the stable carbon isotope 13C in a global ocean biogeochemistry model. The model well reproduces the present-day 13C observations. We find a recent observation-based estimate of the oceanic 13C Suess effect (the decrease in 13C/12C ratio due to uptake of anthropogenic CO2; 13CSE) possibly underestimates 13CSE by 0.1–0.26 per mil. The new model will aid in better understanding the past ocean state via comparison to 13C/12C measurements from sediment cores.
Neil J. Wyatt, Angela Milne, Eric P. Achterberg, Thomas J. Browning, Heather A. Bouman, E. Malcolm S. Woodward, and Maeve C. Lohan
Biogeosciences, 18, 4265–4280,Short summary
Using data collected during two expeditions to the South Atlantic Ocean, we investigated how the interaction between external sources and biological activity influenced the availability of the trace metals zinc and cobalt. This is important as both metals play essential roles in the metabolism and growth of phytoplankton and thus influence primary productivity of the oceans. We found seasonal changes in both processes that helped explain upper-ocean trace metal cycling.
Hannah L. Bourne, James K. B. Bishop, Elizabeth J. Connors, and Todd J. Wood
Biogeosciences, 18, 3053–3086,Short summary
To learn how the biological carbon pump works in productive coastal upwelling systems, four autonomous carbon flux explorers measured carbon flux through the twilight zone beneath an offshore-flowing filament of biologically productive water. Strikingly different particle classes dominated the carbon fluxes during successive stages of the filament evolution over 30 d. Both flux and transfer efficiency were far greater than expected, suggesting an outsized filament impact in California waters.
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,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,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.
Natacha Le Grix, Jakob Zscheischler, Charlotte Laufkötter, Cecile S. Rousseaux, and Thomas L. Frölicher
Biogeosciences, 18, 2119–2137,Short summary
Marine ecosystems could suffer severe damage from the co-occurrence of a marine heat wave with extremely low chlorophyll concentration. Here, we provide a first assessment of compound marine heat wave and low-chlorophyll events in the global ocean from 1998 to 2018. We reveal hotspots of these compound events in the equatorial Pacific and in the Arabian Sea and show that they mostly occur in summer at high latitudes and their frequency is modulated by large-scale modes of climate variability.
Christopher Holder and Anand Gnanadesikan
Biogeosciences, 18, 1941–1970,Short summary
A challenge for marine ecologists in studying phytoplankton is linking small-scale relationships found in a lab to broader relationships observed on large scales in the environment. We investigated whether machine learning (ML) could help connect these small- and large-scale relationships. ML was able to provide qualitative information about the small-scale processes from large-scale information. This method could help identify important relationships from observations in future research.
Natasha René van Horsten, Hélène Planquette, Géraldine Sarthou, Thomas James Ryan-Keogh, Thato Nicholas Mtshali, Alakendra Roychoudhury, and Eva Bucciarelli
Revised manuscript accepted for BGShort 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 inference of carbon remineralisation from satellite data on a basin scale.
Paul J. Tréguer, Jill N. Sutton, Mark Brzezinski, Matthew A. Charette, Timothy Devries, Stephanie Dutkiewicz, Claudia Ehlert, Jon Hawkings, Aude Leynaert, Su Mei Liu, Natalia Llopis Monferrer, María López-Acosta, Manuel Maldonado, Shaily Rahman, Lihua Ran, and Olivier Rouxel
Biogeosciences, 18, 1269–1289,Short summary
Silicon is the second most abundant element of the Earth's crust. In this review, we show that silicon inputs and outputs, to and from the world ocean, are 57 % and 37 % higher, respectively, than previous estimates. These changes are significant, modifying factors such as the geochemical residence time of silicon, which is now about 8000 years and 2 times faster than previously assumed. We also update the total biogenic silica pelagic production and provide an estimate for sponge production.
Caroline Ulses, Claude Estournel, Marine Fourrier, Laurent Coppola, Fayçal Kessouri, Dominique Lefèvre, and Patrick Marsaleix
Biogeosciences, 18, 937–960,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.
Fuminori Hashihama, Hiroaki Saito, Taketoshi Kodama, Saori Yasui-Tamura, Jota Kanda, Iwao Tanita, Hiroshi Ogawa, E. Malcolm S. Woodward, Philip W. Boyd, and Ken Furuya
Biogeosciences, 18, 897–915,Short summary
We investigated the nutrient assimilation characteristics of deep-water-induced phytoplankton blooms across the subtropical North and South Pacific Ocean. Nutrient drawdown ratios of dissolved inorganic nitrogen to phosphate were anomalously low in the western North Pacific, likely due to the high phosphate uptake capability of low-phosphate-adapted phytoplankton. The anomalous phosphate uptake might influence the maintenance of chronic phosphate depletion in the western North Pacific.
Florian Ricour, Arthur Capet, Fabrizio D'Ortenzio, Bruno Delille, and Marilaure Grégoire
Biogeosciences, 18, 755–774,Short summary
This paper addresses the phenology of the deep chlorophyll maximum (DCM) in the Black Sea (BS). We show that the DCM forms in March at a density level set by the winter mixed layer. It maintains this location until June, suggesting an influence of the DCM on light and nutrient profiles rather than mere adaptation to external factors. In summer, the DCM concentrates ~55 % of the chlorophyll in a 10 m layer at ~35 m depth and should be considered a major feature of the BS phytoplankton dynamics.
Robyn E. Tuerena, Joanne Hopkins, Raja S. Ganeshram, Louisa Norman, Camille de la Vega, Rachel Jeffreys, and Claire Mahaffey
Biogeosciences, 18, 637–653,Short summary
The Barents Sea is a rapidly changing shallow sea within the Arctic. Here, nitrate, an essential nutrient, is fully consumed by algae in surface waters during summer months. Nitrate is efficiently regenerated in the Barents Sea, and there is no evidence for nitrogen loss from the sediments by denitrification, which is prevalent on other Arctic shelves. This suggests that nitrogen availability in the Barents Sea is largely determined by the supply of nutrients in water masses from the Atlantic.
Biogeosciences, 18, 509–534,Short summary
Biogeochemical-Argo floats are starting to routinely measure ocean chlorophyll, nutrients, oxygen, and pH. This study generated synthetic observations representing two potential Biogeochemical-Argo observing system designs and created a data assimilation scheme to combine them with an ocean model. The proposed system of 1000 floats brought clear benefits to model results, with additional floats giving further benefit. Existing satellite ocean colour observations gave complementary information.
Mark Hague and Marcello Vichi
Biogeosciences, 18, 25–38,Short summary
This paper examines the question of what causes the rapid spring growth of microscopic marine algae (phytoplankton) in the ice-covered ocean surrounding Antarctica. One prominent hypothesis proposes that the melting of sea ice is the primary cause, while our results suggest that this is only part of the explanation. In particular, we show that phytoplankton are able to start growing before the sea ice melts appreciably, much earlier than previously thought.
Arthur Capet, Luc Vandenbulcke, and Marilaure Grégoire
Biogeosciences, 17, 6507–6525,Short summary
The Black Sea is 2000 m deep, but, due to limited ventilation, only about the upper 100 m contains enough oxygen to support marine life such as fish. This oxygenation depth has been shown to be decreasing (1955–2019). Here, we evidence that atmospheric warming induced a clear shift in an important ventilation mechanism. We highlight the impact of this shift on oxygenation. There are important implications for marine life and carbon and nutrient cycling if this new ventilation regime persists.
Tim Rixen, Greg Cowie, Birgit Gaye, Joaquim Goes, Helga do Rosário Gomes, Raleigh R. Hood, Zouhair Lachkar, Henrike Schmidt, Joachim Segschneider, and Arvind Singh
Biogeosciences, 17, 6051–6080,Short summary
The northern Indian Ocean hosts an extensive oxygen minimum zone (OMZ), which intensified due to human-induced global changes. This includes the occurrence of anoxic events on the Indian shelf and affects benthic ecosystems and the pelagic ecosystem structure in the Arabian Sea. Consequences for biogeochemical cycles are unknown, which, in addition to the poor representation of mesoscale features, reduces the reliability of predictions of the future OMZ development in the northern Indian Ocean.
Marion Lagarde, Nolwenn Lemaitre, Hélène Planquette, Mélanie Grenier, Moustafa Belhadj, Pascale Lherminier, and Catherine Jeandel
Biogeosciences, 17, 5539–5561,
Randelle M. Bundy, Alessandro Tagliabue, Nicholas J. Hawco, Peter L. Morton, Benjamin S. Twining, Mariko Hatta, Abigail E. Noble, Mattias R. Cape, Seth G. John, Jay T. Cullen, and Mak A. Saito
Biogeosciences, 17, 4745–4767,Short summary
Cobalt (Co) is an essential nutrient for ocean microbes and is scarce in most areas of the ocean. This study measured Co concentrations in the Arctic Ocean for the first time and found that Co levels are extremely high in the surface waters of the Canadian Arctic. Although the Co primarily originates from the shelf, the high concentrations persist throughout the central Arctic. Co in the Arctic appears to be increasing over time and might be a source of Co to the North Atlantic.
Friedrich A. Burger, Jasmin G. John, and Thomas L. Frölicher
Biogeosciences, 17, 4633–4662,Short summary
Ensemble simulations of an Earth system model reveal that ocean acidity extremes have increased in the past few decades and are projected to increase further in terms of frequency, intensity, duration, and volume extent. The increase is not only caused by the long-term ocean acidification due to the uptake of anthropogenic CO2, but also due to changes in short-term variability. The increase in ocean acidity extremes may enhance the risk of detrimental impacts on marine organisms.
Christopher Gordon, Katja Fennel, Clark Richards, Lynn K. Shay, and Jodi K. Brewster
Biogeosciences, 17, 4119–4134,Short summary
We describe a method for correcting errors in oxygen optode measurements on autonomous platforms in the ocean. The errors result from the relatively slow response time of the sensor. The correction method includes an in situ determination of the effective response time and requires the time stamps of the individual measurements. It is highly relevant for the BGC-Argo program and also applicable to gliders. We also explore if diurnal changes in oxygen can be obtained from profiling floats.
Bin Wang, Katja Fennel, Liuqian Yu, and Christopher Gordon
Biogeosciences, 17, 4059–4074,Short summary
We assess trade-offs between different types of biological observations, specifically satellite ocean color and BGC-Argo profiles and the benefits of combining both for optimizing a biogeochemical model of the Gulf of Mexico. Using all available observations leads to significant improvements in observed and unobserved variables (including primary production and C export). Our results highlight the significant benefits of BGC-Argo measurements for biogeochemical model optimization and validation.
Bruce L. Greaves, Andrew T. Davidson, Alexander D. Fraser, John P. McKinlay, Andrew Martin, Andrew McMinn, and Simon W. Wright
Biogeosciences, 17, 3815–3835,Short summary
We observed that variation in the Southern Annular Mode (SAM) over 11 years showed a relationship with the species composition of hard-shelled phytoplankton in the seasonal ice zone (SIZ) of the Southern Ocean. Phytoplankton in the SIZ are productive during the southern spring and summer when the area is ice-free, with production feeding most Antarctic life. The SAM is known to be increasing with climate change, and changes in phytoplankton in the SIZ may have implications for higher life forms.
Vincent Taillandier, Louis Prieur, Fabrizio D'Ortenzio, Maurizio Ribera d'Alcalà, and Elvira Pulido-Villena
Biogeosciences, 17, 3343–3366,Short summary
This study addresses the role played by vertical diffusion in the nutrient enrichment of the Levantine intermediate waters, a process particularly relevant inside thermohaline staircases. Thanks to a high profiling frequency over a 4-year period, BGC-Argo float observations reveal the temporal continuity of the layering patterns encountered during the cruise PEACETIME and their impact on vertical and lateral transfers of nitrate between the deep reservoir and the surface productive zone.
Coraline Leseurre, Claire Lo Monaco, Gilles Reverdin, Nicolas Metzl, Jonathan Fin, Solveig Olafsdottir, and Virginie Racapé
Biogeosciences, 17, 2553–2577,Short summary
In this study, we investigate the evolution of CO2 uptake and ocean acidification in the North Atlantic Subpolar surface water. Our results show an important reduction in the capacity of the ocean to absorb CO2 from the atmosphere (1993–2007), due to a rapid increase in the fCO2 and associated with a rapid decrease in pH. Conversely, data obtained during the last decade (2008–2017) show a stagnation of fCO2 (increasing the ocean sink for CO2) and pH.
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,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.
Al-Qutob, M., Hase, C., Tilzer, M. M., and Lazar, B.: Phytoplankton drives nitrite dynamics in the Gulf of Aqaba, Red Sea, Mar. Ecol. Prog. Ser., 239, 233–239, https://doi.org/10.3354/meps239233, 2002.
Azam, F., Fenchel, T., Field, G., Graf, J. S., Meyer-Reil, L. A., and Thingstad, F.: The ecological role of water-column microbes in the sea, Mar. Ecol. Prog. Ser., 10, 257–263, https://doi.org/10.3354/meps010257, 1983.
Baker, A. R. and Jickells, T. D.: Atmospheric deposition of soluble trace elements along the Atlantic Meridional Transect (AMT), Prog. Oceanogr., 158, 41–51, https://doi.org/10.1016/j.pocean.2016.10.002, 2017.
Beman, J. M., Popp, B. N., and Francis, C. A.: Molecular and biogeochemical evidence for ammonia oxidation by marine Crenarchaeota in the Gulf of California, ISME J., 2, 429–441, https://doi.org/10.1038/ismej.2007.118, 2008.
Beman, J. M., Chow, C.-E., King, A., Feng, Y., Fuhrman, J. A., Andersson, A., Bates, N. R., Popp, B. N., and Hutchins, D. A.: Global declines in oceanic nitrification rates as a consequence of ocean acidification, P. Natl. Acad. Sci. USA, 108, 208–213, https://doi.org/10.1073/pnas.1011053108 2011, 2011.
Beman, J. M., Popp, B. N., and Alford, S. E.: Quantification of ammonia oxidation rates and ammonia-oxidizing archaea and bacteria at high resolution in the Gulf of California and eastern tropical North Pacific Ocean, Limnol. Oceanogr., 57, 711–726, https://doi.org/10.4319/lo.2012.57.3.0711, 2012.
Benner, R. and Amon, R. M. W.: The size-reactivity of major bio-elements in the ocean, Ann. Rev. Sci. 7, 185–205, doi.org/10.1146/annurev-marine-010213-135126, 2015.
Bernhard, A. E., Landry, Z. C., Blevins, A., de la Torre, J. R., Giblin, A. E., and Stahl, D. A.: Abundance of ammonia-oxidizing Archaea and Bacteria along an estuarine salinity gradient in relationship to potential nitrification rates, Appl. Environ. Microbiol., 76, 1285–1289, https://doi.org/10.1128/AEM.02018-09, 2010.
Blackburn, T. H.: Method for measuring rates of turnover in anoxic marine sediments, using a 15N- dilution technique, Appl. Environ. Microbiol., 37, 760–765, 1979.
Bouskill, N. J., Eveillard, D., Chien, D., Jayakumar, A., and Ward, B. B.: Environmental factors determining ammonia-oxidizing organism distribution and diversity in marine environments, Environ. Microbiol., 14, 714–729, https://doi.org/10.1111/j.1462-2920.2011.02623.x, 2012.
Buchwald, C. and Casciotti, K. L.: Isotopic ratios of nitrite as tracers of the sources and age of oceanic nitrite, Nat. Geosci., 6, 308–313, https://doi.org/10.1038/ngeo1745, 2013.
Caperon, J., Schell, D., Hirota, J., and Laws, E.: Ammonium excretion rates in Kaneohe Bay, Hawaii, measured by a 15N isotope dilution technique, Mar. Biol., 54, 33–40, 1979.
Chen, Y. J., Bardhan, P., Zhao, X. F., Zheng, M. F., Qiu, Y. S., and Chen, M.: Nitrite Cycle Indicated by Dual Isotopes in the Northern South China Sea, J. Geophys. Res.-Biogeo., 126, e2020JG006129, https://doi.org/10.1029/2020JG006129. 2021.
Christian, J. R., Verschell, M. A., Murtugudde, R., Busalacchi, A. J., and McClain, C. R.: Biogeochemical modelling of the tropical Pacific Ocean. I: Seasonal and interannual variability, Deep-Sea Res. Pt. II, 49, 509–543, https://doi.org/10.1016/S0967-0645(01)00110-2, 2002.
Church, M. J., Karl, D. M., and DeLong, E. F.: Abundances of crenarchaeal amoA genes and transcripts in the Pacific Ocean, Environ. Microbiol., 12, 679–688, https://doi.org/10.1111/j.1462-2920.2009.02108.x, 2010.
Clark, D. R., Flynn, K. J., and Owens, N. J. P.: The large capacity for dark nitrate-assimilation in diatoms may overcome nitrate limitation of growth, New Phytol., 155, 101–108, https://doi.org/10.1046/j.1469-8137.2002.00435.x, 2002.
Clark, D. R., Fileman, T. W., and Joint, I.: Determination of ammonium regeneration rates in the oligotrophic ocean by gas chromatography/mass spectrometry, Mar. Chem., 98, 21–130, https://doi.org/10.1016/j.marchem.2005.08.006, 2006.
Clark, D. R., Rees, A. P., and Joint, I.: A method for the determination of nitrification rates in oligotrophic marine seawater by gas chromatography/mass spectrometry, Mar. Chem., 103, 84–96, https://doi.org/10.1016/j.marchem.2006.06.005, 2007.
Clark, D. R., Rees, A. P., and Joint, I.: Ammonium regeneration and nitrification rates in the oligotrophic Atlantic Ocean: Implications for new production estimates, Limnol. Oceanogr., 53, 52–62, https://doi.org/10.2307/40006149, 2008.
Clark, D. R., Brown, I. J., Rees, A. P., Somerfield, P. J., and Miller, P. I.: The influence of ocean acidification on nitrogen regeneration and nitrous oxide production in the northwest European shelf sea, Biogeosciences, 11, 4985–5005, https://doi.org/10.5194/bg-11-4985-2014, 2014.
Clark, D., Rees, A., and Ferrera, C.: oxidation rates in the oligotrophic Atlantic Ocean using 15N isotope dilution methods during the AMT programme cruise AMT19 (JC039),British Oceanographic Data Centre – Natural Environment Research Council, UK, [data set] https://doi.org/10.5285/56df6379-5b2b-160b-e053-6c86abc01f07, 2017.
Clarke, K. R. and Warwick, R. M.: Quantifying structural redundancy in ecological communities, Oecologia, 113, 278–289, https://doi.org/10.1007/s004420050379, 1998.
Clarke, K. R., Somerfield, P. J., and Gorley, R. N.: Testing of null hypotheses in exploratory community analyses: similarity profiles and biota-environment linkage, J. Exp. Mar. Biol. Ecol., 366, 56–69, https://doi.org/10.1016/j.jembe.2008.07.009, 2008.
Clarke, K. R., Gorley, R. N., Somerfield, P. J., and Warwick, R. M.: Change in marine communities: an approach to statistical analysis and interpretation, 3 Edn., PRIMER-E, Plymouth., 256 pp, 2014.
Dandonneau, Y., Vega, A., Loisel, H., du Penhoat, Y., and Menkes, C.: Oceanic Rossby waves acting as a hay rake for ecosystem floating by-products, Science, 302, 1548–1551, https://doi.org/10.1126/science.1090729, 2003.
de Vet, W. W. J. M., van Loosdrecht, M. C. M., and Rietveld, L. C.: Phosphorus limitation in nitrifying groundwater filters, Water Res., 46, 1061–1069, https://doi.org/10.1016/j.watres.2011.11.075, 2012.
Dore, J. E. and Karl, D. M.: Nitrification in the euphotic zone as a source for nitrite, nitrate and nitrous oxide at Station ALOHA, Limnol. Oceanogr., 41, 1619–1628, https://doi.org/10.4319/lo.19188.8.131.529, 1996.
Emerson, S., Mecking, S., and Abell, J.: The biological pump in the subtropical North Pacific Ocean: Nutrient sources, Redfield ratios, and recent changes, Global Biogeochem. Cy., 15, 535–554, https://doi.org/10.1029/2000GB001320, 2001.
Eppley, R. W. and Peterson, B. J.: Particulate organic matter flux and planktonic new production in the deep ocean, Nature, 282, 677–680, 1979.
Fawcett, S. E., Ward, B. B., Lomas, M. W., and Sigman, D. M.: Vertical decoupling of nitrate assimilation and nitrification in the Sargasso Sea, Deep-Sea Res. Pt. I, 103, 64–72, https://doi.org/10.1016/j.dsr.2015.05.004, 2015.
Francis, C., A., Beman, J. M., and Kuypers, M. M. M.: New processes and players in the nitrogen cycle: The microbial ecology of anaerobic and archaeal ammonia oxidation, ISME J., 1, 19–27, https://doi.org/10.1038/ismej.2007.8, 2007.
French, D., Furnas, M., and Smayda, T.: Diel changes in nitrite concentration in the chlorophyll maximum in the Gulf of Mexico, Deep-Sea Res., 30, 707–722, https://doi.org/10.1016/0198-0149(83)90018-3, 1983.
Giovanoni, S. J. and Vergin, K. L.: Seasonality in ocean microbial communities, Science, 335, 671–676, https://doi.org/10.1126/science.1198078, 2012.
Gruber, N. and Sarmiento, J. L.: Global patterns of marine nitrogen fixation and denitrification, Global Biogeochem. Cy., 11, 235–266, https://doi.org/10.1029/97GB00077, 1997.
Horak, R. E. A., Qin, W., Schauer, A. J., Armbrust, E. V., Ingalls, A. E., Moffett, J. W., Stahl, D. A., and Devol, A. H.: Ammonia oxidation kinetics and temperature sensitivity of a natural marine community dominated by Archaea, ISME. 7, 2023–2033, https://doi.org/10.1038/ismej.2013.75, 2013.
Horak, R. E. A., Qin, W., Bertagnolli, A. D., et al.: Relative impacts of light, temperature, and reactive oxygen on thaumarchaeal ammonia oxidation in the North Pacific Ocean, Limnol. Oceanogr., 63, 741–757, https://doi.org/10.1002/lno.10665, 2017.
IOC: Intergovernmental Oceanographic Commission, Paris, Protocols for the Joint Global Flux Study (JGOFS) core measurements, Manuals Guides, 29 pp., 1994.
Jiang, M. S., Chai, F., Dugdale, R. C., Wilkerson, F. P., Peng, T. H., and Barber, R. T.: A nitrate and silicate budget in the equatorial Pacific Ocean: a coupled physical-biological model study, Deep-Sea Res. Pt. II, 50, 2971–2996, https://doi.org/10.1016/j.dsr2.2003.07.006, 2003.
Jiao, N., Herndl, G. J., Hansell, D. A., Benner, R., Kattner, G., Wilhelm, S. W., Kirchman, D. L., Weinbauer, M. G., Luo, T., Chen, F., and Azam, F.: Microbial production of recalcitrant dissolved organic matter: long-term carbon storage in the global ocean, Nat. Rev. Microbiol., 8, 593–599, https://doi.org/10.1038/nrmicro2386, 2010.
Karstensen, J., Stramma, L., and Visbeck, M.: Oxygen minimum zones in the eastern tropical Atlantic and Pacific oceans, Prog. Oceanogr., 77, 331–350, https://doi.org/10.1016/j.pocean.2007.05.009, 2008.
Kieber, R. J., Li, A., and Seaton, P. J.: Production of nitrite from the photodegradation of dissolved organic matter in natural waters, Environ. Sci. Technol., 33, 993–998, https://doi.org/10.1021/es980188a, 1999.
Kiørboe, T.: Turbulence, phytoplankton cell size, and the structure of pelagic food webs, Adv. Mar. Biol., 29, 2–72, https://doi.org/10.1016/S0065-2881(08)60129-7, 1993.
Klass, C. and Archer, D.: Association of sinking organic matter with various types of mineral ballast in the deep sea: Implications for the rain ratio, Global Biogeochem. Cy., 16, 1116, https://doi.org/10.1029/2001GB001765, 2002.
Laws, E. A., Letelier, R. M., and Karl, D. M.: Estimating the compensation irradiance in the ocean: The importance of accounting for non-photosynthetic uptake of inorganic carbon, Deep-Sea Res. Pt. I, 93, 35–40, https://doi.org/10.1016/j.dsr.2014.07.011 2014.
Legeais, J.-F., Ablain, M., Zawadzki, L., Zuo, H., Johannessen, J. A., Scharffenberg, M. G., Fenoglio-Marc, L., Fernandes, M. J., Andersen, O. B., Rudenko, S., Cipollini, P., Quartly, G. D., Passaro, M., Cazenave, A., and Benveniste, J.: An improved and homogeneous altimeter sea level record from the ESA Climate Change Initiative, Earth Syst. Sci. Data, 10, 281–301, https://doi.org/10.5194/essd-10-281-2018, 2018.
Letelier, R. M., Karl, D. M., Abbott, M. R., and Bidigare, R. R.: Light driven seasonal patterns of chlorophyll and nitrate in the lower euphotic zone of the North Pacific Subtropical Gyre, Limnol. Oceanogr., 49, 508–519, https://doi.org/10.4319/lo.2004.49.2.0508, 2004.
Letscher, R. T., Hansell, D. A., Carlson, C. A., Lumpkin, R., and Knapp, A. N.: Dissolved organic nitrogen in the global surface ocean: Distribution and fate, Global Biogeochem. Cy., 27, 141–153, https://doi.org/10.1029/2012GB004449, 2013.
Lomas, M. W. and Gilbert, P. M.: Temperature regulation of nitrate uptake: A novel hypothesis about nitrate uptake and reduction in cool-water diatoms, Limnol. Oceanogr., 44, 556–572, https://doi.org/10.4319/lo.1999.44.3.0556, 1999.
Lomas, M. W. and Gilbert, P. M.: Comparisons of nitrate uptake, storage and reduction in marine diatoms and dinoflagellates, J. Phycol., 36, 903–913, https://doi.org/10.1046/j.1529-8817.2000.99029.x, 2000.
Lomas, M. W. and Lipschultz, F.: Forming the primary nitrite maximum: Nitrifiers or phytoplankton?, Limnol. Oceanogr., 51, 2453–2467, https://doi.org/10.4319/lo.2006.51.5.2453, 2006.
Lomas, M. W., Lipschultz, F., Nelson, D. M., Krause, J. W., and Bates, N. R.: Biogeochemical responses to late-winter storms in the Sargasso Sea, I – Pulses of primary and new production, Deep-Sea Res. Pt. I, 56, 843–860, https://doi.org/10.1016/j.dsr.2009.01.002, 2009.
Longhurst, A.: Ecological geography of the sea, Academic Press, ISBN: 9780124555587, 1998.
Mackey, K. R. M., Bristow, L., Parks, D. R., Altabet, M. A., Post, A. F., and Paytan, A.: The influence of light on nitrogen cycling and the primary nitrite maximum in a seasonally stratified sea, Prog. Oceanogr., 91, 545–560, https://doi.org/10.1016/j.pocean.2011.09.001, 2011.
Mahaffey, C., Williams, R. G., Wolff, G. A., and Anderson, W. T.: Physical supply of nitrogen to phytoplankton in the Atlantic Ocean, Global Biogeochem. Cy., 18, GB1034, https://doi.org/10.1029/2003GB002129, 2004.
Maranñón, E., Holligan, P. M., Varela, M., Mourinõ, B., and Bale, A. J.: Basinscale variability of phytoplankton biomass, production and growth in the Atlantic Ocean, Deep-Sea Res. Pt. I, 47, 825–857, https://doi.org/10.1016/S0967-0637(99)00087-4, 2000.
Martens-Habbena, W., Berube, P. M., Urakawa, H., de la Torre, J. R., and Stahl, D. A.: Ammonia oxidation kinetics determine niche separation of nitrifying Archaea and Bacteria, Nature, 461, 976–979, https://doi.org/10.1038/nature08465, 2009.
McClain, C. R., Signorini, S. R., and Christian, J. R.: Subtropical gyre variability observed by ocean-color satellites, Deep-Sea Res. Pt. I, 51, 281–301, https://doi.org/10.1016/j.dsr2.2003.08.002, 2004.
McGillicuddy, D. J., Jr, Robinson, A. R., Siegel, D. A., Jannasch, H. W., Johnson, R., Dickey, T. D., McNeil, J., Michaels, A. F., and Knap, A. H.: Influence of mesoscale eddies on new production in the Sargasso Sea, Nature, 394, 263–266, https://doi.org/10.1038/28367, 1998.
Meeder, E., Mackey, K. R. M., Paytan, A., Shaked, Y., Iluz, D., Stambler, N., Rivlin, T., Post, A. F., and Lazar, B.: Nitrite dynamics in the open ocean–clues from seasonal and diurnal variations, Mar. Ecol. Prog. Ser., 453, 11–26, https://doi.org/10.3354/meps09525, 2012.
Mills, M. M., Ridame, C., Davey, M., La Roche, J., and Geider, R. J.: Iron and phosphorus co-limit nitrogen fixation in the eastern tropical North Atlantic, Nature, 429, 292–294, https://doi.org/10.1038/nature03632, 2004.
Mitra, A., Flynn, K. J., Burkholder, J. M., Berge, T., Calbet, A., Raven, J. A., Granéli, E., Glibert, P. M., Hansen, P. J., Stoecker, D. K., Thingstad, F., Tillmann, U., Våge, S., Wilken, S., and Zubkov, M. V.: The role of mixotrophic protists in the biological carbon pump, Biogeosciences, 11, 995–1005, https://doi.org/10.5194/bg-11-995-2014, 2014.
Moore, C. M., Mills, M. M., Achterberg, E. P., Geider, R. J., LaRoche, J., Lucas, M. I., McDonagh, E. L., Pan, X., Poulton, A. J., Rijkenberg, M. J. A., Suggett, D. J., Ussher, S. J., and Woodward, E. M. S.: Large-scale distribution of Atlantic nitrogen fixation controlled by iron availability, Nat. Geosci., 2, 867–871, https://doi.org/10.1038/NGEO667, 2009.
Moore, C. M., Mills, 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., Marañón, E., Marinov, I., Moore, J. K., Nakatsuka, T., Oschlies, A., Saito, M. A., Thingstad, T. F., Tsudaand, A., and Ulloa, O.: Processes and patterns of oceanic nutrient limitation, Nat. Geosci., 6, 701–710, https://doi.org/10.1038/NGEO1765, 2013.
Moore, J. K., Doney, S. C., Kleypas, J. A., Glover, D. M., and Fung I. Y.: An intermediate complexity marine ecosystem model for the global domain, Deep-Sea Res. Pt. II, 49, 403–462, https://doi.org/10.1016/S0967-0645(01)00108-4, 2002.
Mulholland, M. R.: The fate of nitrogen fixed by diazotrophs in the ocean, Biogeosciences, 4, 37–51, https://doi.org/10.5194/bg-4-37-2007, 2007.
Nencioli, F., Dall'Olmo, G., and Quartly, G. D.: Agulhas ring transport efficiency from combined satellite altimetry and Argo profiles, J. Geophys. Res.-Oceans, 123, 5874–5888, https://doi.org/10.1029/2018JC013909, 2018.
Newell, S. E., Babbin, A. R., Jayakumar, A., and Ward, B. B.: Ammonia oxidation rates and nitrification in the Arabian Sea, Global Biogeochem. Cy., 25, GB4016, https://doi.org/10.1029/2010GB003940, 2011.
Newell, S. E., Fawcett, S. E., and Ward, B. B.: Depth distribution of ammonia oxidation rates and ammonia-oxidizer community composition in the Sargasso Sea, Limnol Oceanogr., 58, 491–1500, https://doi.org/10.4319/lo.2013.58.4.1491, 2013.
Olson, R. J.: Differential photoinhibition of marine nitrifying bacteria: A possible mechanism for the formation of the primary nitrite maximum, J. Mar. Res., 39, 227–238, https://doi.org/10.4319/lo.2006.51.5.2453, 1981.
Oschlies, A. and Garçon, V.: Eddy-induced enhancement of primary production in a model of the North Atlantic Ocean, Nature, 394, 266–269, https://doi.org/10.1038/28373, 1998.
Palinska, K. A., Laloui, W., Bédu, S., Goer, S. L., Castets, A. M., Rippka, R., and de Marsac, N. T.: The signal transducer P-II and bicarbonate acquisition in Prochlorococcus marinus PCC 9511, a marine cyanobacterium naturally deficient in nitrate and nitrite assimilation, Microbiology, 148, 2405–2412, https://doi.org/10.1099/00221287-148-8-2405, 2002.
Partensky, F., Hess, W. R., and Vaulot, D.: Prochlorococcus, a Marine Photosynthetic Prokaryote of Global Significance, Microbiol. Mol. Biol., 63, 6–127, https://doi.org/10.1016/j.procbio.2007.09.010, 1999.
Peng, X., Fawcett, S. E., van Oostende, N., Wolf, M. J., Marconi, D., Sigman, D. M., and Ward, B. B.: Nitrogen uptake and nitrification in the subarctic North Atlantic Ocean, Limnol. Oceanogr., 63, 1462–1487, https://doi.org/10.1002/lno.10784, 2018.
Planas. D., Agusti, S., Duarte, C. M., Granata, T. C., and Merino, M.: Nitrate uptake and diffusive nitrate supply in the Central Atlantic, Limnol. Oceanogr., 44, 116-126, https://doi.org/10.4319/lo.1999.44.1.011, 1999.
Polovina, J. J., Howell, E. A., and Abecassis, M.: Ocean's least productive waters are expanding, Geophys. Res. Lett., 35, L03618, https://doi.org/10.1029/2007GL031745, 2008.
Poulton, A. J., Holligan, P. M., Hickman, A., Kim, Y-N., Adey, T. R., Stinchcombe, M. C., Holeton, C., Root, S., and Woodward, E. M. S.: Phytoplankton carbon fixation, chlorophyll-biomass and diagnostic pigments in the Atlantic Ocean, Deep-Sea Res. Pt. II, 53, 1593–1610, https://doi.org/10.1016/j.dsr2.2006.05.007, 2006.
Poulton, A. J., Holligan, P. M., Charalampopoulou, A., and Adey, T. R.: Coccolithophore ecology in the tropical and subtropical Atlantic Ocean: new perspectives from the Atlantic meridional transect (AMT) programme, Prog. Oceanogr., 158, 150–170, https://doi.org/10.1016/j.pocean.2017.01.003, 2017.
Quartly, G. D., Legeais, J.-F., Ablain, M., Zawadzki, L., Fernandes, M. J., Rudenko, S., Carrère, L., García, P. N., Cipollini, P., Andersen, O. B., Poisson, J.-C., Mbajon Njiche, S., Cazenave, A., and Benveniste, J.: A new phase in the production of quality-controlled sea level data, Earth Syst. Sci. Data, 9, 557–572, https://doi.org/10.5194/essd-9-557-2017, 2017.
Rafter, P. A., DiFiore, P. J., and Sigman, D. M.: Coupled nitrate nitrogen and oxygen isotopes and organic matter remineralization in the Southern and Pacific Oceans, J. Geophys. Res., 118, 4781–4794, https://doi.org/10.1002/jgrc.20316, 2013.
Raes, E. J., van de Kamp, J., Bodrossy, L., Fong, A. A., Riekenberg, J., Holmes, B. H., Erler, D. V., Eyre, B. D., Weil, S.-S., and Waite, A. M.: N2 Fixation and New Insights Into Nitrification From the Ice-Edge to the Equator in the South Pacific Ocean, Front. Mar. Sci., 7, 389, https://doi.org/10.3389/fmars.2020.00389, 2020.
Rees, A. P., Nightingale, P. D., Poulton, A. J., Smyth, T., Tarran, G. A., and Tilstone, G. H.: The Atlantic Meridional Transect programme (1995–2016), Prog. Oceanogr., 158, 3–18, https://doi.org/10.1016/j.pocean.2017.05.004, 2017.
Santoro, A. E., Sakamoto, C. M., Smith, J. M., Plant, J. N., Gehman, A. L., Worden, A. Z., Johnson, K. S., Francis, C. A., and Casciotti, K. L.: Measurements of nitrite production in and around the primary nitrite maximum in the central California Current, Biogeosciences, 10, 7395–7410, https://doi.org/10.5194/bg-10-7395-2013, 2013.
Sarmiento, J. L., Gruber, N., Brzezinski, M. A., and Dunne, J. P.: High-latitude controls of thermocline nutrients and low latitude biological productivity, Nature, 427, 5660, https://doi.org/10.1038/nature10605, 2004.
Scharek, R., Tupas, L. M., and Karl, D. M.: Diatom fluxes to the deep sea in the oligotrophic North Pacific gyre at Station ALOHA, Mar. Ecol. Prog. Ser., 182, 55–67, https://doi.org/10.3354/meps182055, 1999.
Shiozaki, T., Ijichi, M., Isobe, K., Hashihama, F., Nakamura, K., Ehama, M., Hayashizaki, K., Takahashi, K., Hamasaki, K., and Furuya, K.: Nitrification and its influence on biogeochemical cycles from the equatorial Pacific to the Arctic Ocean, ISME J., 10, 2184–2197, https://doi.org/10.1038/ismej.2016.18, 2016.
Smith, J. M., Chavez, F. P., and Francis, C. A.: Ammonium Uptake by Phytoplankton Regulates Nitrification in the Sunlit Ocean, PLoS ONE, 9, e108173, https://doi.org/10.1371/journal.pone.0108173, 2014.
Smith, J. M., Damashek, J., Chavez, F. P., and Francis, C. A.: Factors influencing nitrification rates and the abundance and transcriptional activity of ammonia-oxidizing microorganisms in the dark northeast Pacific Ocean, Limnol. Oceanogr., 61, 596–609, https://doi.org/10.1002/lno.10235, 2016.
Somerfield, P. J. and Clarke, K. R.: Inverse analysis in non-parametric multivariate analyses: distinguishing groups of associated species which covary coherently across samples, J. Exp. Mar. Biol. Ecol., 449, 261–273, https://doi.org/10.1016/j.jembe.2013.10.002, 2013.
Somerfield, P. J., Clarke, K. R., and Gorley, R. N.: Analysis of Similarities (ANOSIM) for 2-way layouts using a generalised ANOSIM statistic, with comparative notes on Permutational Multivariate Analysis of Variance (PERMANOVA), Austr. Ecol., 46, 911–926, https://doi.org/10.1111/aec.13059, 2021.
Tarran, G. A. and Zubkov, M. V.: Abundance of microbial phytoplankton through the water column during the AMT19 (JC039) cruise in October-December 2009, British Oceanographic Data Centre, National Oceanography Centre, NERC, UK, [data set], https://doi.org/10.5285/a2104adc-e994-6789-e053-6c86abc0d557, 2020.
Taylor, A. H., Harris, J. R. W., and Aiken, J.: The interaction of physical and biological processes in a model of the vertical distribution of phytoplankton under stratification, in: Marine Interfaces Echohydrodynamics, edited by: Nihoul, J. C. J., Elsevier Science, Amsterdam, The Netherlands, 313–330, https://doi.org/10.1016/S0422-9894(08)71052-3, 1986.
Treusch, A. H., Vergin, K. L. Finlay, L. A., Donatz, M. G., Burton, R. M., Carlson, C. A., and Giovannoni, S. J.: Seasonality and vertical structure of microbial communities in an ocean gyre, ISME J., 3, 1148–1163, https://doi.org/10.1038/ismej.2009.60, 2009.
Torres-Valdés, S., Roussenov, V. M., Sanders, R., Reynolds, S., Pan, X., Mather, R., Landolfi, A., Wolff, G. A., Achterberg, E. P., and Williams, R. G.: Distribution of dissolved organic nutrients and their effect on export production over the Atlantic Ocean, Global. Biogeochem. Cy., 23, GB4019, https://doi.org/10.1029/2008GB003389, 2009.
Tuerena, R. E., Ganeshram, R .S., Geibert, W., Fallick, A. E., Dougans, J., Tait, A., Henley, S. F., and Woodward, E. M. S.: Nutrient cycling in the Atlantic basin: The evolution of nitrate isotope signatures in water masses, Global Biogeochem. Cy., 29, 1830–1844, https://doi.org/10.1002/2015GB005164, 2015.
Tuerena, R. E., Williams, R. G., Mahaffey, C., Vic, C., Green, J. A. M., Naveira-Garabato, A., Forryan, A., and Sharples, J.: Internal Tides Drive Nutrient Fluxes Into the Deep Chlorophyll Maximum Over Mid-ocean Ridges, Global Biogeochem. Cy., 33, 995–1009, https://doi.org/10.1029/2019GB006214, 2019.
Wan, X. S., Sheng, H.-X., Dai, M., Church, M. J., Zou, W., Li, X., Hutchins, D. A., Ward, B. B., and Kao, S.-J.: Phytoplankton-nitrifier interactions control the geographic distribution of nitrite in the upper ocean, Global Biogeochem. Cy., 35, e2021GB007072, https://doi.org/10.1029/2021GB007072, 2021.
Wang, X. J., Christian, J. R., Murtugudde, R., and Busalacchi, A. J.: Spatial and temporal variability in new production in the equatorial Pacific during 1980-2003: Physical and biogeochemical controls, Deep-Sea Res. Pt. II, 53, 677–697, https://doi.org/10.1016/j.dsr2.2006.01.023, 2006.
Ward, B. B.: Light and substrate concentration relationships with marine ammonium assimilation and oxidation rates, Mar. Chem., 16, 301–316, https://doi.org/10.1016/0304-4203(85)90052-0, 1985.
Ward, B. B.: Temporal variability in nitrification rates and related biogeochemical factors in Monterey Bay, California, USA, Mar. Ecol. Prog. Ser., 292, 97–109, https://doi.org/10.3354/meps292097, 2005.
Ward, B. B.: Measurement and distribution of nitrification rates in the oceans, Methods Enzym., 486, 307–323, doi.org/10.1016/B978-0-12-381294-0.00013-4, 2007.
Ward, B. B.: Nitrification in marine systems, in: Nitrogen in the Marine Environment, edited by: Capone, D., Bronk, D. A., Mulholland, M. R., and Carpenter, E. J., Elsevier Press, 199–261, 2008.
Ward, B. B., Glover, H. E., and Lipshultz, F.: Chemoauto-trophic activity and nitrification in the oxygen minimum zone off Peru, Deep-Sea Res., 36, 1031–1051, https://doi.org/10.1016/0198-0149(89)90076-9, 1989.
Ward, B. B.: Nitrification in aquatic systems, in: Encyclopaedia of Environmental Microbiology, edited by: Capone, D. A., Wiley, New York, NY, USA, 2144–2167, https://doi.org/10.1002/0471263397.env287, 2002.
Zafiriou, O. C. and True, M. B.: Nitrate photolysis in seawater by sunlight, Mar. Chem., 8, 33–42, https://doi.org/10.1016/0304-4203(79)90029-X, 1979.
Woodward, E. M. S. and Rees, A. P.: Nutrient distributions in an anticyclonic eddy in the North East Atlantic Ocean, with reference to nanomolar ammonium concentrations, Deep-Sea Res., 48, 775–794, https://doi.org/10.1016/S0967-0645(00)00097-7, 2001.
Yool, A., Martin, A. P., Fernández, C., and Clark, D. R.: The significance of nitrification for oceanic new production, Nature, 447, 999–1002, https://doi.org/10.1038/nature05885, 2007.
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.
Measurements of microbial processes were made in the sunlit open ocean during a research cruise...