Articles | Volume 18, issue 6
https://doi.org/10.5194/bg-18-1941-2021
© Author(s) 2021. 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-18-1941-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
19 Mar 2021
Research article |
| 19 Mar 2021
| 19 Mar 2021
Can machine learning extract the mechanisms controlling phytoplankton growth from large-scale observations? – A proof-of-concept study
Morton K. Blaustein Department of Earth and Planetary Sciences,
Johns Hopkins University, Baltimore, MD 21218, United States of America
Anand Gnanadesikan
Morton K. Blaustein Department of Earth and Planetary Sciences,
Johns Hopkins University, Baltimore, MD 21218, United States of America
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Christopher Holder, Anand Gnanadesikan, and Marie Aude-Pradal
Geosci. Model Dev., 15, 1595–1617, https://doi.org/10.5194/gmd-15-1595-2022, https://doi.org/10.5194/gmd-15-1595-2022, 2022
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It can be challenging to understand why Earth system models (ESMs) produce specific results because one can arrive at the same result simply by changing the values of the parameters. In our paper, we demonstrate that it is possible to use machine learning to figure out how and why particular components of an ESM (such as biology or ocean circulations) affect the output. This work could be applied to observations to improve the accuracy of the formulations used in ESMs.
Christopher Holder, Anand Gnanadesikan, and Marie Aude-Pradal
Geosci. Model Dev., 15, 1595–1617, https://doi.org/10.5194/gmd-15-1595-2022, https://doi.org/10.5194/gmd-15-1595-2022, 2022
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It can be challenging to understand why Earth system models (ESMs) produce specific results because one can arrive at the same result simply by changing the values of the parameters. In our paper, we demonstrate that it is possible to use machine learning to figure out how and why particular components of an ESM (such as biology or ocean circulations) affect the output. This work could be applied to observations to improve the accuracy of the formulations used in ESMs.
S. Sedigh Marvasti, A. Gnanadesikan, A. A. Bidokhti, J. P. Dunne, and S. Ghader
Biogeosciences, 13, 1049–1069, https://doi.org/10.5194/bg-13-1049-2016, https://doi.org/10.5194/bg-13-1049-2016, 2016
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This study examines challenges in modeling phytoplankton blooms in Northwestern Arabian Sea and Gulf of Oman. Blooms in the region show strong modulation both by seasons and in the wintertime by eddies. However getting both of these correct is a challenge in a set of state-of-the-art global Earth System models. It is argued that maintaining a sharp pycnocline may be the key for preventing the wintertime bloom from being too strong and for allowing eddies to modulate upward mixing of nutrients.
A. Goswami, P. L. Olson, L. A. Hinnov, and A. Gnanadesikan
Geosci. Model Dev., 8, 2735–2748, https://doi.org/10.5194/gmd-8-2735-2015, https://doi.org/10.5194/gmd-8-2735-2015, 2015
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A methodology is presented for reconstructing past global ocean bathymetry using a plate cooling model for the oceanic lithosphere, the age distribution of the oceanic crust, global oceanic sediment thicknesses, plus shelf-slope-rise structures calibrated at modern active and passive continental margins. The final product is a globally complete ocean bathymetry at arbitrary resolution with an isostatically adjusted, multicomponent sediment layer.
G. E. Kim, M.-A. Pradal, and A. Gnanadesikan
Biogeosciences, 12, 5119–5132, https://doi.org/10.5194/bg-12-5119-2015, https://doi.org/10.5194/bg-12-5119-2015, 2015
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Light absorption by colored detrital material (CDM) was included in a fully coupled Earth system model. Chlorophyll and biomass increased near the surface but decreased at greater depths when CDM was included. Concurrently, total biomass decreased leaving more nutrients in the water. Regional changes were analyzed by comparing the competing factors of diminished light availability and increased nutrient availability on phytoplankton growth.
N. Towles, P. Olson, and A. Gnanadesikan
Clim. Past, 11, 991–1007, https://doi.org/10.5194/cp-11-991-2015, https://doi.org/10.5194/cp-11-991-2015, 2015
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In this paper we find scaling relationships for perturbations to atmosphere and ocean variables from large transient CO2 emissions. We use a carbon cycle box model to calculate peak perturbations to a variety of ocean and atmosphere variables resulting from idealized emission events. As these scaling relationships depend on the physical setup, they represent a compact way of characterizing how different climates respond to large transient perturbations.
A. Gnanadesikan, M.-A. Pradal, and R. Abernathey
Ocean Sci., 11, 591–605, https://doi.org/10.5194/os-11-591-2015, https://doi.org/10.5194/os-11-591-2015, 2015
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Many ocean circulation models use representations of lateral mixing based on instability theories that predict weak mixing in the ocean interior, much lower than observed. We show that using more realistic mixing improves the distribution of mantle helium-3. It does not, however, resolve the paradox that models reproduce the relationship between mantle helium and radiocarbon with a flux of helium-3 lower than is consistent with the heat leaving the mantle.
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Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, and Karen L. Casciotti
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Biogeosciences, 19, 5807–5835, https://doi.org/10.5194/bg-19-5807-2022, https://doi.org/10.5194/bg-19-5807-2022, 2022
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Compound events threaten marine ecosystems. Here, we investigate the potentially harmful combination of marine heatwaves with low phytoplankton productivity. Using satellite-based observations, we show that these compound events are frequent in the low latitudes. We then investigate the drivers of these compound events using Earth system models. The models share similar drivers in the low latitudes but disagree in the high latitudes due to divergent factors limiting phytoplankton production.
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Biogeosciences, 19, 5499–5520, https://doi.org/10.5194/bg-19-5499-2022, https://doi.org/10.5194/bg-19-5499-2022, 2022
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We focus on the exchange of key nutrients for algae production between the Arctic and Atlantic oceans through the Fram Strait. We show that the export of dissolved silicon here is controlled by the availability of nitrate which is influenced by denitrification on Arctic shelves. We suggest that any future changes in the river inputs of silica and changes in denitrification due to climate change will impact the amount of silicon exported, with impacts on Atlantic algal productivity and ecology.
Emily J. Zakem, Barbara Bayer, Wei Qin, Alyson E. Santoro, Yao Zhang, and Naomi M. Levine
Biogeosciences, 19, 5401–5418, https://doi.org/10.5194/bg-19-5401-2022, https://doi.org/10.5194/bg-19-5401-2022, 2022
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We use a microbial ecosystem model to quantitatively explain the mechanisms controlling observed relative abundances and nitrification rates of ammonia- and nitrite-oxidizing microorganisms in the ocean. We also estimate how much global carbon fixation can be associated with chemoautotrophic nitrification. Our results improve our understanding of the controls on nitrification, laying the groundwork for more accurate predictions in global climate models.
Zuozhu Wen, Thomas J. Browning, Rongbo Dai, Wenwei Wu, Weiying Li, Xiaohua Hu, Wenfang Lin, Lifang Wang, Xin Liu, Zhimian Cao, Haizheng Hong, and Dalin Shi
Biogeosciences, 19, 5237–5250, https://doi.org/10.5194/bg-19-5237-2022, https://doi.org/10.5194/bg-19-5237-2022, 2022
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Fe and P are key factors controlling the biogeography and activity of marine N2-fixing microorganisms. We found lower abundance and activity of N2 fixers in the northern South China Sea than around the western boundary of the North Pacific, and N2 fixation rates switched from Fe–P co-limitation to P limitation. We hypothesize the Fe supply rates and Fe utilization strategies of each N2 fixer are important in regulating spatial variability in community structure across the study area.
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Biogeosciences, 19, 5079–5106, https://doi.org/10.5194/bg-19-5079-2022, https://doi.org/10.5194/bg-19-5079-2022, 2022
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Given the sparsity of observational constraints on micronutrients such as zinc (Zn), we assess the sensitivities of a framework for objective parameter optimisation in an oceanic Zn cycling model. Our ensemble of optimisations towards synthetic data with varying kinds of uncertainty shows that deficiencies related to model complexity and the choice of the misfit function generally have a greater impact on the retrieval of model Zn uptake behaviour than does the limitation of data coverage.
Alban Planchat, Lester Kwiatkwoski, 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
EGUsphere, https://doi.org/10.5194/egusphere-2022-1041, https://doi.org/10.5194/egusphere-2022-1041, 2022
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Ocean alkalinity is critical to the uptake of atmospheric carbon and acidification in surface waters. We review the representation of alkalinity and the associated calcium carbonate cycle in Earth system models. While many parameterizations remain present in the latest generation of models, there is a general improvement in the simulated alkalinity distribution. This improvement is related to an increase in the export of biotic calcium carbonate, which closer resembles observations.
Yoshikazu Sasai, Sherwood Lan Smith, Eko Siswanto, Hideharu Sasaki, and Masami Nonaka
Biogeosciences, 19, 4865–4882, https://doi.org/10.5194/bg-19-4865-2022, https://doi.org/10.5194/bg-19-4865-2022, 2022
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We have investigated the adaptive response of phytoplankton growth to changing light, nutrients, and temperature over the North Pacific using two physical-biological models. We compare modeled chlorophyll and primary production from an inflexible control model (InFlexPFT), which assumes fixed carbon (C):nitrogen (N):chlorophyll (Chl) ratios, to a recently developed flexible phytoplankton functional type model (FlexPFT), which incorporates photoacclimation and variable C:N:Chl ratios.
Jens Terhaar, Thomas L. Frölicher, and Fortunat Joos
Biogeosciences, 19, 4431–4457, https://doi.org/10.5194/bg-19-4431-2022, https://doi.org/10.5194/bg-19-4431-2022, 2022
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Estimates of the ocean sink of anthropogenic carbon vary across various approaches. We show that the global ocean carbon sink can be estimated by three parameters, two of which approximate the ocean ventilation in the Southern Ocean and the North Atlantic, and one of which approximates the chemical capacity of the ocean to take up carbon. With observations of these parameters, we estimate that the global ocean carbon sink is 10 % larger than previously assumed, and we cut uncertainties in half.
Katherine E. Turner, Doug M. Smith, Anna Katavouta, and Richard G. Williams
Biogeosciences Discuss., https://doi.org/10.5194/bg-2022-166, https://doi.org/10.5194/bg-2022-166, 2022
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We present a new method for reconstructing ocean carbon using climate models and temperature and salinity fields. We test this method by reconstructing modelled carbon fields using synthetic observations consistent with current sampling programmes. Sensitivity tests find that the method can reproduce both trends and variability in upper-ocean carbon. Our results indicate that this method can provide a new estimate for ocean carbon stocks and can be used to compare with existing carbon products.
Natasha René van Horsten, Hélène Planquette, Géraldine Sarthou, Thomas James Ryan-Keogh, Nolwenn Lemaitre, Thato Nicholas Mtshali, Alakendra Roychoudhury, and Eva Bucciarelli
Biogeosciences, 19, 3209–3224, https://doi.org/10.5194/bg-19-3209-2022, https://doi.org/10.5194/bg-19-3209-2022, 2022
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The remineralisation proxy, barite, was measured along 30°E in the southern Indian Ocean during early austral winter. To our knowledge this is the first reported Southern Ocean winter study. Concentrations throughout the water column were comparable to observations during spring to autumn. By linking satellite primary production to this proxy a possible annual timescale is proposed. These findings also suggest possible carbon remineralisation from satellite data on a basin scale.
Zhibo Shao and Ya-Wei Luo
Biogeosciences, 19, 2939–2952, https://doi.org/10.5194/bg-19-2939-2022, https://doi.org/10.5194/bg-19-2939-2022, 2022
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Non-cyanobacterial diazotrophs (NCDs) may be an important player in fixing N2 in the ocean. By conducting meta-analyses, we found that a representative marine NCD phylotype, Gamma A, tends to inhabit ocean environments with high productivity, low iron concentration and high light intensity. It also appears to be more abundant inside cyclonic eddies. Our study suggests a niche differentiation of NCDs from cyanobacterial diazotrophs as the latter prefers low-productivity and high-iron oceans.
Coraline Leseurre, Claire Lo Monaco, Gilles Reverdin, Nicolas Metzl, Jonathan Fin, Claude Mignon, and Léa Benito
Biogeosciences, 19, 2599–2625, https://doi.org/10.5194/bg-19-2599-2022, https://doi.org/10.5194/bg-19-2599-2022, 2022
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Decadal trends of fugacity of CO2 (fCO2), total alkalinity (AT), total carbon (CT) and pH in surface waters are investigated in different domains of the southern Indian Ocean (45°S–57°S) from ongoing and station observations regularly conducted in summer over the period 1998–2019. The fCO2 increase and pH decrease are mainly driven by anthropogenic CO2 estimated just below the summer mixed layer, as well as by a warming south of the polar front or in the fertilized waters near Kerguelen Island.
Priscilla Le Mézo, Jérôme Guiet, Kim Scherrer, Daniele Bianchi, and Eric Galbraith
Biogeosciences, 19, 2537–2555, https://doi.org/10.5194/bg-19-2537-2022, https://doi.org/10.5194/bg-19-2537-2022, 2022
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This study quantifies the role of commercially targeted fish biomass in the cycling of three important nutrients (N, P, and Fe), relative to nutrients otherwise available in water and to nutrients required by primary producers, and the impact of fishing. We use a model of commercially targeted fish biomass constrained by fish catch and stock assessment data to assess the contributions of fish at the global scale, at the time of the global peak catch and prior to industrial fishing.
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
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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
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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
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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
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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
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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
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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, https://doi.org/10.5194/bg-19-845-2022, https://doi.org/10.5194/bg-19-845-2022, 2022
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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, https://doi.org/10.5194/bg-19-715-2022, https://doi.org/10.5194/bg-19-715-2022, 2022
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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, https://doi.org/10.5194/bg-19-437-2022, https://doi.org/10.5194/bg-19-437-2022, 2022
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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, https://doi.org/10.5194/bg-19-415-2022, https://doi.org/10.5194/bg-19-415-2022, 2022
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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, https://doi.org/10.5194/bg-19-347-2022, https://doi.org/10.5194/bg-19-347-2022, 2022
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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, https://doi.org/10.5194/bg-18-6479-2021, https://doi.org/10.5194/bg-18-6479-2021, 2021
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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, https://doi.org/10.5194/bg-18-6435-2021, https://doi.org/10.5194/bg-18-6435-2021, 2021
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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, https://doi.org/10.5194/bg-18-6377-2021, https://doi.org/10.5194/bg-18-6377-2021, 2021
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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, https://doi.org/10.5194/bg-18-6147-2021, https://doi.org/10.5194/bg-18-6147-2021, 2021
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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, https://doi.org/10.5194/bg-18-5871-2021, https://doi.org/10.5194/bg-18-5871-2021, 2021
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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, https://doi.org/10.5194/bg-18-5831-2021, https://doi.org/10.5194/bg-18-5831-2021, 2021
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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, https://doi.org/10.5194/bg-18-5699-2021, https://doi.org/10.5194/bg-18-5699-2021, 2021
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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, https://doi.org/10.5194/bg-18-5423-2021, https://doi.org/10.5194/bg-18-5423-2021, 2021
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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, https://doi.org/10.5194/bg-18-5265-2021, https://doi.org/10.5194/bg-18-5265-2021, 2021
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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, https://doi.org/10.5194/bg-18-5011-2021, https://doi.org/10.5194/bg-18-5011-2021, 2021
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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, https://doi.org/10.5194/bg-18-4953-2021, https://doi.org/10.5194/bg-18-4953-2021, 2021
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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, https://doi.org/10.5194/bg-18-4389-2021, https://doi.org/10.5194/bg-18-4389-2021, 2021
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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, https://doi.org/10.5194/bg-18-4265-2021, https://doi.org/10.5194/bg-18-4265-2021, 2021
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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, https://doi.org/10.5194/bg-18-3053-2021, https://doi.org/10.5194/bg-18-3053-2021, 2021
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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, https://doi.org/10.5194/bg-18-2663-2021, https://doi.org/10.5194/bg-18-2663-2021, 2021
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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
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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, https://doi.org/10.5194/bg-18-2119-2021, https://doi.org/10.5194/bg-18-2119-2021, 2021
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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.
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, https://doi.org/10.5194/bg-18-1269-2021, https://doi.org/10.5194/bg-18-1269-2021, 2021
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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, https://doi.org/10.5194/bg-18-937-2021, https://doi.org/10.5194/bg-18-937-2021, 2021
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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, https://doi.org/10.5194/bg-18-897-2021, https://doi.org/10.5194/bg-18-897-2021, 2021
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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, https://doi.org/10.5194/bg-18-755-2021, https://doi.org/10.5194/bg-18-755-2021, 2021
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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, https://doi.org/10.5194/bg-18-637-2021, https://doi.org/10.5194/bg-18-637-2021, 2021
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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.
Cited articles
Bahl, A., Gnanadesikan, A., and Pradal, M.-A.: Variations in Ocean
Deoxygenation Across Earth System Models: Isolating the Role of
Parameterized Lateral Mixing, Global Biogeochem. Cy., 33, 703–724,
https://doi.org/10.1029/2018GB006121, 2019.
Belochitski, A., Binev, P., DeVore, R., Fox-Rabinovitz, M., Krasnopolsky, V.,
and Lamby, P.: Tree approximation of the long wave radiation
parameterization in the NCAR CAM global climate model, J. Comput. Appl.
Math., 236, 447–460, https://doi.org/10.1016/j.cam.2011.07.013, 2011.
Bourel, M., Crisci, C., and Martínez, A.: Consensus methods based on
machine learning techniques for marine phytoplankton presence–absence
prediction, Ecol. Inform., 42, 46–54, https://doi.org/10.1016/j.ecoinf.2017.09.004,
2017.
Boyd, P. W., Jickells, T., Law, C. S., Blain, S., Boyle, E. A., Buesseler,
K. O., Coale, K. H., Cullen, J. J., de Baar, H. J. W., Follows, M., Harvey,
M., Lancelot, C., Levasseur, M., Owens, N. P. J., Pollard, R., Rivkin, R.
B., Sarmiento, J., Schoemann, V., Smetacek, V., Takeda, S., Tsuda, A.,
Turner, S., and Watson, A. J.: Mesoscale Iron Enrichment Experiments
1993–2005: Synthesis and Future Directions, Science, 315, 612–617,
2007.
Breiman, L.: Random forests, Mach. Learn., 45, 5–32, 2001.
Brenowitz, N. D. and Bretherton, C. S.: Prognostic Validation of a Neural
Network Unified Physics Parameterization, Geophys. Res. Lett., 45,
6289–6298, https://doi.org/10.1029/2018GL078510, 2018.
Brzezinski, M. A. and Nelson, D. M.: The annual silica cycle in the Sargasso
Sea near Bermuda, Deep-Sea Res. Pt. I, 42, 1215–1237,
https://doi.org/10.1016/0967-0637(95)93592-3, 1995.
Chase, Z., Strutton, P. G., and Hales, B.: Iron links river runoff and shelf
width to phytoplankton biomass along the U.S. West Coast, Geophys. Res.
Lett., 34, L04607, https://doi.org/10.1029/2006GL028069, 2007.
Chevallier, F., Chéruy, F., Scott, N. A., and Chédin, A.: A Neural
Network Approach for a Fast and Accurate Computation of a Longwave Radiative
Budget, J. Appl. Meteorol., 37, 1385–1397,
https://doi.org/10.1175/1520-0450(1998)037<1385:ANNAFA>2.0.CO;2,
1998.
Downing, J. A., Osenberg, C. W., and Sarnelle, O.: Meta-Analysis of Marine
Nutrient-Enrichment Experiments: Variation in the Magnitude of Nutrient
Limitation, Ecology, 80, 1157–1167, https://doi.org/10.2307/177063, 1999.
Dugdale, R. C., Wilkerson, F. P., and Minas, H. J.: The role of a silicate
pump in driving new production, Deep-Sea Res. Pt. I.,
42, 697–719, https://doi.org/10.1016/0967-0637(95)00015-X, 1995.
Dunne, J. P., John, J. G., Shevliakova, E., Stouffer, R. J., Krasting, J.
P., Malyshev, S. L., Milly, P. C. D., Sentman, L. T., Adcroft, A. J., Cooke,
W., Dunne, K. A., Griffies, S. M., Hallberg, R. W., Harrison, M. J., Levy,
H., Wittenberg, A. T., Phillips, P. J., and Zadeh, N.: GFDL's ESM2 Global
Coupled Climate-Carbon Earth System Models. Part II: Carbon System
Formulation and Baseline Simulation Characteristics*, J. Climate, 26,
2247–2267, https://doi.org/10.1175/JCLI-D-12-00150.1, 2013.
Egge, J. and Aksnes, D.: Silicate as regulating nutrient in phytoplankton
competition, Mar. Ecol.-Prog. Ser., 83, 281–289, https://doi.org/10.3354/meps083281,
1992.
Eppley, R. W.: Temperature and phytoplankton growth in the sea, Fish. Bull.,
70, 1063–1085, 1972.
Eppley, R. W. and Thomas, W. H.: Comparison of Half-Saturation Constants for
Growth and Nitrate Uptake of Marine Phytoplankton 2, J. Phycol., 5,
375–379, https://doi.org/10.1111/j.1529-8817.1969.tb02628.x, 1969.
Eppley, R. W., Renger, E. H., Venrick, E. L., and Mullin, M. M.: A Study of
Plankton Dynamics and Nutrient Cycling in the Central Gyre of the North
Pacific Ocean, Limnol. Oceanogr., 18, 534–551, 1973.
Flombaum, P., Wang, W.-L., Primeau, F. W., and Martiny, A. C.: Global
picophytoplankton niche partitioning predicts overall positive response to
ocean warming, Nat. Geosci., 13, 116–120, https://doi.org/10.1038/s41561-019-0524-2,
2020.
Franceschini, S., Tancioni, L., Lorenzoni, M., Mattei, F.,
and Scardi, M.: An ecologically constrained procedure for sensitivity
analysis of Artificial Neural Networks and other empirical models, Plos One, 14, e0211445, https://doi.org/10.1371/journal.pone.0211445, 2019.
Galbraith, E. D., Gnanadesikan, A., Dunne, J. P., and Hiscock, M. R.: Regional impacts of iron-light colimitation in a global biogeochemical model, Biogeosciences, 7, 1043–1064, https://doi.org/10.5194/bg-7-1043-2010, 2010.
Galbraith, E. D., Kwon, E. Y., Gnanadesikan, A., Rodgers, K. B., Griffies,
S. M., Bianchi, D., Sarmiento, J. L., Dunne, J. P., Simeon, J., Slater, R.
D., Wittenberg, A. T., and Held, I. M.: Climate Variability and Radiocarbon
in the CM2Mc Earth System Model, J. Climate, 24, 4230–4254,
https://doi.org/10.1175/2011JCLI3919.1, 2011.
Galbraith, E. D., Dunne, J. P., Gnanadesikan, A., Slater, R. D., Sarmiento,
J. L., Dufour, C. O., Souza, G. F. de, Bianchi, D., Claret, M., Rodgers, K.
B., and Marvasti, S. S.: Complex functionality with minimal computation:
Promise and pitfalls of reduced-tracer ocean biogeochemistry models, J. Adv.
Model. Earth Sy., 7, 2012–2028, https://doi.org/10.1002/2015MS000463, 2015.
Geider, R. J., MacIntyre, H. L., and Kana, T. M.: Dynamic model of
phytoplankton growth and acclimation: responses of the balanced growth rate
and the chlorophyll a: carbon ratio to light, nutrient-limitation and
temperature, Mar. Ecol.-Prog. Ser., 148, 187–200, 1997.
Gentine, P., Pritchard, M., Rasp, S., Reinaudi, G., and Yacalis, G.: Could
Machine Learning Break the Convection Parameterization Deadlock?, Geophys.
Res. Lett., 45, 5742–5751, https://doi.org/10.1029/2018GL078202, 2018.
Guégan, J.-F., Lek, S., and Oberdorff, T.: Energy availability and
habitat heterogeneity predict global riverine fish diversity, Nature,
391, 382–384, https://doi.org/10.1038/34899, 1998.
Hansen, L. K. and Salamon, P.: Neural network ensembles, IEEE T. Pattern
Anal., 12, 993–1001, https://doi.org/10.1109/34.58871, 1990.
Harding, L. W., Adolf, J. E., Mallonee, M. E., Miller, W. D., Gallegos, C.
L., Perry, E. S., Johnson, J. M., Sellner, K. G., and Paerl, H. W.: Climate
effects on phytoplankton floral composition in Chesapeake Bay, Estuar.
Coast. Shelf Sci., 162, 53–68, https://doi.org/10.1016/j.ecss.2014.12.030, 2015.
Hassler, C. S., Sinoir, M., Clementson, L. A., and Butler, E. C. V.:
Exploring the Link between Micronutrients and Phytoplankton in the Southern
Ocean during the 2007 Austral Summer, Front. Microbiol., 3, 202,
https://doi.org/10.3389/fmicb.2012.00202, 2012.
Holder, C. and Gnanadesikan, A.: Dataset and scripts for manuscript “Can
machine learning extract the mechanisms controlling phytoplankton growth
from large-scale observations? – A proof of concept study”, Zenodo, https://doi.org/10.5281/zenodo.3932387, 2020.
Krasnopolsky, V. M., Fox-Rabinovitz, M. S., and Belochitski, A. A.:
Development of neural network convection parameterizations for numerical
climate and weather prediction models using cloud resolving model
simulations, in: The 2010 International Joint Conference on Neural Networks
(IJCNN), 18–23 July 2010, Barcelona, Spain, 1–8, 2010.
Krasnopolsky, V. M., Fox-Rabinovitz, M. S., and Belochitski, A. A.: Using
Ensemble of Neural Networks to Learn Stochastic Convection Parameterizations
for Climate and Numerical Weather Prediction Models from Data Simulated by a
Cloud Resolving Model, Adv. Artif. Neural Syst., 2013, 485913, https://doi.org/10.1155/2013/485913,
2013.
Kruk, C. and Segura, A. M.: The habitat template of phytoplankton
morphology-based functional groups, Hydrobiologia, 698, 191–202,
https://doi.org/10.1007/s10750-012-1072-6, 2012.
Kruk, C., Peeters, E. T. H. M., Nes, E. H. V., Huszar, V. L. M., Costa, L.
S., and Scheffer, M.: Phytoplankton community composition can be predicted
best in terms of morphological groups, Limnol. Oceanogr., 56, 110–118,
https://doi.org/10.4319/lo.2011.56.1.0110, 2011.
Ku, T.-L., Luo, S., Kusakabe, M., and Bishop, J. K. B.: 228Ra-derived
nutrient budgets in the upper equatorial Pacific and the role of “new”
silicate in limiting productivity, Deep-Sea Res. Pt. II, 42, 479–497, https://doi.org/10.1016/0967-0645(95)00020-Q, 1995.
Lek, S., Delacoste, M., Baran, P., Dimopoulos, I., Lauga, J., and Aulagnier,
S.: Application of neural networks to modelling nonlinear relationships in
ecology, Ecol. Model., 90, 39–52, https://doi.org/10.1016/0304-3800(95)00142-5,
1996a.
Lek, S., Belaud, A., Baran, P., Dimopoulos, I., and Delacoste, M.: Role of
some environmental variables in trout abundance models using neural
networks, Aquat. Living Resour., 9, 23–29, https://doi.org/10.1051/alr:1996004,
1996b.
Longhurst, A., Sathyendranath, S., Platt, T., and Caverhill, C.: An estimate
of global primary production in the ocean from satellite radiometer data, J.
Plankton Res., 17, 1245–1271, https://doi.org/10.1093/plankt/17.6.1245, 1995.
Löptien, U. and Dietze, H.: Reciprocal bias compensation and ensuing uncertainties in model-based climate projections: pelagic biogeochemistry versus ocean mixing, Biogeosciences, 16, 1865–1881, https://doi.org/10.5194/bg-16-1865-2019, 2019.
Maldonado, M. T. and Price, N. M.: Influence of N substrate on Fe
requirements of marine centric diatoms, Mar. Ecol.-Prog. Ser., 141,
161–172, https://doi.org/10.3354/meps141161, 1996.
Martin, J. H.: Glacial-interglacial CO2 change: The Iron Hypothesis,
Paleoceanography, 5, 1–13, https://doi.org/10.1029/PA005i001p00001, 1990.
Martin, J. H. and Fitzwater, S. E.: Iron deficiency limits phytoplankton
growth in the north-east Pacific subarctic, Nature, 331, 341–343,
https://doi.org/10.1038/331341a0, 1988.
MATLAB: MATLAB version 9.7.0.1319299 (R2019b) Update 5, The Mathworks, Inc., Natick, Massachusetts, 2019.
Mattei, F., Franceschini, S., and Scardi, M.: A depth-resolved artificial
neural network model of marine phytoplankton primary production, Ecol.
Model., 382, 51–62, https://doi.org/10.1016/j.ecolmodel.2018.05.003, 2018.
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., Tsuda, A., and Ulloa, O.: Processes and patterns of oceanic
nutrient limitation, Nat. Geosci., 6, 701–710, https://doi.org/10.1038/ngeo1765,
2013.
O'Gorman, P. A. and Dwyer, J. G.: Using Machine Learning to Parameterize
Moist Convection: Potential for Modeling of Climate, Climate Change, and
Extreme Events, J. Adv. Model. Earth Sy., 10, 2548–2563,
https://doi.org/10.1029/2018MS001351, 2018.
Olden, J. D.: An artificial neural network approach for studying
phytoplankton succession, Hydrobiologia, 436, 131–143,
https://doi.org/10.1023/A:1026575418649, 2000.
Özesmi, S. L. and Özesmi, U.: An artificial neural network approach
to spatial habitat modelling with interspecific interaction, Ecol. Model.,
116, 15–31, https://doi.org/10.1016/S0304-3800(98)00149-5, 1999.
Price, N. M., Andersen, L. F., and Morel, F. M. M.: Iron and nitrogen
nutrition of equatorial Pacific plankton, Deep-Sea Res. Pt. I, 38, 1361–1378, https://doi.org/10.1016/0198-0149(91)90011-4, 1991.
Rasp, S., Pritchard, M. S., and Gentine, P.: Deep learning to represent
subgrid processes in climate models, P. Natl. Acad. Sci. USA, 115,
9684–9689, https://doi.org/10.1073/pnas.1810286115, 2018.
Rivero-Calle, S., Gnanadesikan, A., Castillo, C. E. D., Balch, W. M., and
Guikema, S. D.: Multidecadal increase in North Atlantic coccolithophores and
the potential role of rising CO2, Science, 350, 1533–1537,
https://doi.org/10.1126/science.aaa8026, 2015.
Ryther, J. H. and Dunstan, W. M.: Nitrogen, Phosphorus, and Eutrophication
in the Coastal Marine Environment, Science, 171, 1008–1013, 1971.
Saito, M. A., Goepfert, T. J., and Ritt, J. T.: Some Thoughts on the Concept
of Colimitation: Three Definitions and the Importance of Bioavailability,
Limnol. Oceanogr., 53, 276–290, 2008.
Sarmiento, J. L., Slater, R., Barber, R., Bopp, L., Doney, S. C., Hirst, A.
C., Kleypas, J., Matear, R., Mikolajewicz, U., Monfray, P., Soldatov, V.,
Spall, S. A., and Stouffer, R.: Response of ocean ecosystems to climate
warming, Global Biogeochem. Cy., 18, GB3003, https://doi.org/10.1029/2003GB002134, 2004.
Scardi, M.: Artificial neural networks as empirical models for estimating
phytoplankton production, Mar. Ecol.-Prog. Ser., 139, 289–299, 1996.
Scardi, M.: Advances in neural network modeling of phytoplankton primary
production, Ecol. Model., 146, 33–45, https://doi.org/10.1016/S0304-3800(01)00294-0,
2001.
Scardi, M. and Harding, L. W.: Developing an empirical model of
phytoplankton primary production: a neural network case study, Ecol. Model.,
120, 213–223, https://doi.org/10.1016/S0304-3800(99)00103-9, 1999.
Schmidhuber, J.: Deep learning in neural networks: An overview, Neural
Netw., 61, 85–117, https://doi.org/10.1016/j.neunet.2014.09.003, 2015.
Schoffman, H., Lis, H., Shaked, Y., and Keren, N.: Iron–Nutrient
Interactions within Phytoplankton, Front. Plant Sci., 7, 1223,
https://doi.org/10.3389/fpls.2016.01223, 2016.
Vince, S. and Valiela, I.: The effects of ammonium and phosphate enrichments
on clorophyll a, pigment ratio and species composition of phytoplankton of
Vineyard Sound, Mar. Biol., 19, 69–73, https://doi.org/10.1007/BF00355422, 1973.
Wang, W.-X. and Dei, R. C. H.: Biological uptake and assimilation of iron by
marine plankton: influences of macronutrients, Mar. Chem., 74, 213–226,
https://doi.org/10.1016/S0304-4203(01)00014-7, 2001.
Wong, C. S. and Matear, R. J.: Sporadic silicate limitation of phytoplankton
productivity in the subarctic NE Pacific, Deep-Sea Res. Pt. II, 46, 2539–2555, https://doi.org/10.1016/S0967-0645(99)00075-2, 1999.
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.
A challenge for marine ecologists in studying phytoplankton is linking small-scale relationships...
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