Articles | Volume 17, issue 15
https://doi.org/10.5194/bg-17-4059-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/bg-17-4059-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
11 Aug 2020
Research article |
| 11 Aug 2020
| 11 Aug 2020
Assessing the value of biogeochemical Argo profiles versus ocean color observations for biogeochemical model optimization in the Gulf of Mexico
Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada
Katja Fennel
Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada
Liuqian Yu
Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada
Department of Mathematics, The Hong Kong University of Science and Technology, Kowloon, Hong Kong
Christopher Gordon
Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, Canada
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Angela M. Kuhn, Katja Fennel, and Ilana Berman-Frank
Biogeosciences, 15, 7379–7401, https://doi.org/10.5194/bg-15-7379-2018, https://doi.org/10.5194/bg-15-7379-2018, 2018
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Bin Wang, Jiatang Hu, Shiyu Li, Liuqian Yu, and Jia Huang
Biogeosciences, 15, 6105–6125, https://doi.org/10.5194/bg-15-6105-2018, https://doi.org/10.5194/bg-15-6105-2018, 2018
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Krysten Rutherford and Katja Fennel
Ocean Sci., 14, 1207–1221, https://doi.org/10.5194/os-14-1207-2018, https://doi.org/10.5194/os-14-1207-2018, 2018
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Katja Fennel and Arnaud Laurent
Biogeosciences, 15, 3121–3131, https://doi.org/10.5194/bg-15-3121-2018, https://doi.org/10.5194/bg-15-3121-2018, 2018
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Jonathan Lemay, Helmuth Thomas, Susanne E. Craig, William J. Burt, Katja Fennel, and Blair J. W. Greenan
Biogeosciences, 15, 2111–2123, https://doi.org/10.5194/bg-15-2111-2018, https://doi.org/10.5194/bg-15-2111-2018, 2018
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Julia M. Moriarty, Courtney K. Harris, Katja Fennel, Marjorie A. M. Friedrichs, Kehui Xu, and Christophe Rabouille
Biogeosciences, 14, 1919–1946, https://doi.org/10.5194/bg-14-1919-2017, https://doi.org/10.5194/bg-14-1919-2017, 2017
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Zuo Xue, Ruoying He, Katja Fennel, Wei-Jun Cai, Steven Lohrenz, Wei-Jen Huang, Hanqin Tian, Wei Ren, and Zhengchen Zang
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L. Yu, K. Fennel, A. Laurent, M. C. Murrell, and J. C. Lehrter
Biogeosciences, 12, 2063–2076, https://doi.org/10.5194/bg-12-2063-2015, https://doi.org/10.5194/bg-12-2063-2015, 2015
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G. Snider, C. L. Weagle, R. V. Martin, A. van Donkelaar, K. Conrad, D. Cunningham, C. Gordon, M. Zwicker, C. Akoshile, P. Artaxo, N. X. Anh, J. Brook, J. Dong, R. M. Garland, R. Greenwald, D. Griffith, K. He, B. N. Holben, R. Kahn, I. Koren, N. Lagrosas, P. Lestari, Z. Ma, J. Vanderlei Martins, E. J. Quel, Y. Rudich, A. Salam, S. N. Tripathi, C. Yu, Q. Zhang, Y. Zhang, M. Brauer, A. Cohen, M. D. Gibson, and Y. Liu
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K.-K. Liu, C.-K. Kang, T. Kobari, H. Liu, C. Rabouille, and K. Fennel
Biogeosciences, 11, 7061–7075, https://doi.org/10.5194/bg-11-7061-2014, https://doi.org/10.5194/bg-11-7061-2014, 2014
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Z. Xue, R. He, K. Fennel, W.-J. Cai, S. Lohrenz, and C. Hopkinson
Biogeosciences, 10, 7219–7234, https://doi.org/10.5194/bg-10-7219-2013, https://doi.org/10.5194/bg-10-7219-2013, 2013
W. J. Burt, H. Thomas, K. Fennel, and E. Horne
Biogeosciences, 10, 53–66, https://doi.org/10.5194/bg-10-53-2013, https://doi.org/10.5194/bg-10-53-2013, 2013
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Tracing differences in iron supply to the Mid-Atlantic Ridge valley between hydrothermal vent sites: implications for the addition of iron to the deep ocean
Nitrite cycling in the primary nitrite maxima of the eastern tropical North Pacific
Hotspots and drivers of compound marine heatwaves and low net primary production extremes
Ecosystem impacts of marine heat waves in the northeast Pacific
Tracing the role of Arctic shelf processes in Si and N cycling and export through the Fram Strait: insights from combined silicon and nitrate isotopes
Controls on the relative abundances and rates of nitrifying microorganisms in the ocean
The response of diazotrophs to nutrient amendment in the South China Sea and western North Pacific
Influence of GEOTRACES data distribution and misfit function choice on objective parameter retrieval in a marine zinc cycle model
Physiological flexibility of phytoplankton impacts modelled chlorophyll and primary production across the North Pacific Ocean
Observation-constrained estimates of the global ocean carbon sink from Earth system models
Early winter barium excess in the southern Indian Ocean as an annual remineralisation proxy (GEOTRACES GIPr07 cruise)
Controlling factors on the global distribution of a representative marine non-cyanobacterial diazotroph phylotype (Gamma A)
Summer trends and drivers of sea surface fCO2 and pH changes observed in the southern Indian Ocean over the last two decades (1998–2019)
Global nutrient cycling by commercially targeted marine fish
Medhavi Pandey, Haimanti Biswas, Daniel Birgel, Nicole Burdanowitz, and Birgit Gaye
Biogeosciences, 21, 4681–4698, https://doi.org/10.5194/bg-21-4681-2024, https://doi.org/10.5194/bg-21-4681-2024, 2024
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We analysed sea surface temperature (SST) proxy and plankton biomarkers in sediments that accumulate sinking material signatures from surface waters in the central Arabian Sea (21°–11° N, 64° E), a tropical basin impacted by monsoons. We saw a north–south SST gradient, and the biological proxies showed more organic matter from larger algae in the north. Smaller algae and zooplankton were more numerous in the south. These trends were related to ocean–atmospheric processes and oxygen availability.
Allison Hogikyan and Laure Resplandy
Biogeosciences, 21, 4621–4636, https://doi.org/10.5194/bg-21-4621-2024, https://doi.org/10.5194/bg-21-4621-2024, 2024
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Rising atmospheric CO2 influences ocean carbon chemistry, leading to ocean acidification. Global warming introduces spatial patterns in the intensity of ocean acidification. We show that the most prominent spatial patterns are controlled by warming-driven changes in rainfall and evaporation, not by the direct effect of warming on carbon chemistry and pH. These evaporation and rainfall patterns oppose acidification in saltier parts of the ocean and enhance acidification in fresher regions.
Shunya Koseki, Lander R. Crespo, Jerry Tjiputra, Filippa Fransner, Noel S. Keenlyside, and David Rivas
Biogeosciences, 21, 4149–4168, https://doi.org/10.5194/bg-21-4149-2024, https://doi.org/10.5194/bg-21-4149-2024, 2024
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We investigated how the physical biases of an Earth system model influence the marine biogeochemical processes in the tropical Atlantic. With four different configurations of the model, we have shown that the versions with better SST reproduction tend to better represent the primary production and air–sea CO2 flux in terms of climatology, seasonal cycle, and response to climate variability.
Lyuba Novi, Annalisa Bracco, Takamitsu Ito, and Yohei Takano
Biogeosciences, 21, 3985–4005, https://doi.org/10.5194/bg-21-3985-2024, https://doi.org/10.5194/bg-21-3985-2024, 2024
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We explored the relationship between oxygen and stratification in the North Pacific Ocean using a combination of data mining and machine learning. We used isopycnic potential vorticity (IPV) as an indicator to quantify ocean ventilation and analyzed its predictability, a strong O2–IPV connection, and predictability for IPV in the tropical Pacific. This opens new routes for monitoring ocean O2 through few observational sites co-located with more abundant IPV measurements in the tropical Pacific.
Winfred Marshal, Jing Xiang Chung, Nur Hidayah Roseli, Roswati Md Amin, and Mohd Fadzil Bin Mohd Akhir
Biogeosciences, 21, 4007–4035, https://doi.org/10.5194/bg-21-4007-2024, https://doi.org/10.5194/bg-21-4007-2024, 2024
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This study stands out for thoroughly examining CMIP6 ESMs' ability to simulate biogeochemical variables in the southern South China Sea, an economically important region. It assesses variables like chlorophyll, phytoplankton, nitrate, and oxygen on annual and seasonal scales. While global assessments exist, this study addresses a gap by objectively ranking 13 CMIP6 ocean biogeochemistry models' performance at a regional level, focusing on replicating specific observed biogeochemical variables.
Jens Terhaar
Biogeosciences, 21, 3903–3926, https://doi.org/10.5194/bg-21-3903-2024, https://doi.org/10.5194/bg-21-3903-2024, 2024
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Despite the ocean’s importance in the carbon cycle and hence the climate, observing the ocean carbon sink remains challenging. Here, I use an ensemble of 12 models to understand drivers of decadal trends of the past, present, and future ocean carbon sink. I show that 80 % of the decadal trends in the multi-model mean ocean carbon sink can be explained by changes in decadal trends in atmospheric CO2. The remaining 20 % are due to internal climate variability and ocean heat uptake.
Reiner Steinfeldt, Monika Rhein, and Dagmar Kieke
Biogeosciences, 21, 3839–3867, https://doi.org/10.5194/bg-21-3839-2024, https://doi.org/10.5194/bg-21-3839-2024, 2024
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We calculate the amount of anthropogenic carbon (Cant) in the Atlantic for the years 1990, 2000, 2010 and 2020. Cant is the carbon that is taken up by the ocean as a result of humanmade CO2 emissions. To determine the amount of Cant, we apply a technique that is based on the observations of other humanmade gases (e.g., chlorofluorocarbons). Regionally, changes in ocean ventilation have an impact on the storage of Cant. Overall, the increase in Cant is driven by the rising CO2 in the atmosphere.
Stephanie Delacroix, Tor Jensen Nystuen, August E. Dessen Tobiesen, Andrew L. King, and Erik Höglund
Biogeosciences, 21, 3677–3690, https://doi.org/10.5194/bg-21-3677-2024, https://doi.org/10.5194/bg-21-3677-2024, 2024
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The addition of alkaline minerals into the ocean might reduce excessive anthropogenic CO2 emissions. Magnesium hydroxide can be added in large amounts because of its low seawater solubility without reaching harmful pH levels. The toxicity effect results of magnesium hydroxide, by simulating the expected concentrations from a ship's dispersion scenario, demonstrated low impacts on both sensitive and local assemblages of marine microalgae when compared to calcium hydroxide.
Precious Mongwe, Matthew Long, Takamitsu Ito, Curtis Deutsch, and Yeray Santana-Falcón
Biogeosciences, 21, 3477–3490, https://doi.org/10.5194/bg-21-3477-2024, https://doi.org/10.5194/bg-21-3477-2024, 2024
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We use a collection of measurements that capture the physiological sensitivity of organisms to temperature and oxygen and a CESM1 large ensemble to investigate how natural climate variations and climate warming will impact the ability of marine heterotrophic marine organisms to support habitats in the future. We find that warming and dissolved oxygen loss over the next several decades will reduce the volume of ocean habitats and will increase organisms' vulnerability to extremes.
Charly A. Moras, Tyler Cyronak, Lennart T. Bach, Renaud Joannes-Boyau, and Kai G. Schulz
Biogeosciences, 21, 3463–3475, https://doi.org/10.5194/bg-21-3463-2024, https://doi.org/10.5194/bg-21-3463-2024, 2024
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We investigate the effects of mineral grain size and seawater salinity on magnesium hydroxide dissolution and calcium carbonate precipitation kinetics for ocean alkalinity enhancement. Salinity did not affect the dissolution, but calcium carbonate formed earlier at lower salinities due to the lower magnesium and dissolved organic carbon concentrations. Smaller grain sizes dissolved faster but calcium carbonate precipitated earlier, suggesting that medium grain sizes are optimal for kinetics.
Rosie M. Sheward, Christina Gebühr, Jörg Bollmann, and Jens O. Herrle
Biogeosciences, 21, 3121–3141, https://doi.org/10.5194/bg-21-3121-2024, https://doi.org/10.5194/bg-21-3121-2024, 2024
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How quickly do marine microorganisms respond to salinity stress? Our experiments with the calcifying marine plankton Emiliania huxleyi show that growth and cell morphology responded to salinity stress within as little as 24–48 hours, demonstrating that morphology and calcification are sensitive to salinity over a range of timescales. Our results have implications for understanding the short-term role of E. huxleyi in biogeochemical cycles and in size-based paleoproxies for salinity.
Laura Marín-Samper, Javier Arístegui, Nauzet Hernández-Hernández, Joaquín Ortiz, Stephen D. Archer, Andrea Ludwig, and Ulf Riebesell
Biogeosciences, 21, 2859–2876, https://doi.org/10.5194/bg-21-2859-2024, https://doi.org/10.5194/bg-21-2859-2024, 2024
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Our planet is facing a climate crisis. Scientists are working on innovative solutions that will aid in capturing the hard to abate emissions before it is too late. Exciting research reveals that ocean alkalinity enhancement, a key climate change mitigation strategy, does not harm phytoplankton, the cornerstone of marine ecosystems. Through meticulous study, we may have uncovered a positive relationship: up to a specific limit, enhancing ocean alkalinity boosts photosynthesis by certain species.
David Curbelo-Hernández, Fiz F. Pérez, Melchor González-Dávila, Sergey V. Gladyshev, Aridane G. González, David González-Santana, Antón Velo, Alexey Sokov, and J. Magdalena Santana-Casiano
EGUsphere, https://doi.org/10.5194/egusphere-2024-1388, https://doi.org/10.5194/egusphere-2024-1388, 2024
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The study evaluated CO2-carbonate system dynamics in the North Atlantic Subpolar Gyre from 2009 to 2019. Significant ocean acidification, largely due to rising anthropogenic CO2 levels, was found. Cooling, freshening, and enhanced convective processes intensified this trend, affecting calcite and aragonite saturation. The findings contribute to a deeper understanding of Ocean Acidification and improve our knowledge about its impact on marine ecosystems.
France Van Wambeke, Pascal Conan, Mireille Pujo-Pay, Vincent Taillandier, Olivier Crispi, Alexandra Pavlidou, Sandra Nunige, Morgane Didry, Christophe Salmeron, and Elvira Pulido-Villena
Biogeosciences, 21, 2621–2640, https://doi.org/10.5194/bg-21-2621-2024, https://doi.org/10.5194/bg-21-2621-2024, 2024
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Phosphomonoesterase (PME) and phosphodiesterase (PDE) activities over the epipelagic zone are described in the eastern Mediterranean Sea in winter and autumn. The types of concentration kinetics obtained for PDE (saturation at 50 µM, high Km, high turnover times) compared to those of PME (saturation at 1 µM, low Km, low turnover times) are discussed in regard to the possible inequal distribution of PDE and PME in the size continuum of organic material and accessibility to phosphodiesters.
Jenny Hieronymus, Magnus Hieronymus, Matthias Gröger, Jörg Schwinger, Raffaele Bernadello, Etienne Tourigny, Valentina Sicardi, Itzel Ruvalcaba Baroni, and Klaus Wyser
Biogeosciences, 21, 2189–2206, https://doi.org/10.5194/bg-21-2189-2024, https://doi.org/10.5194/bg-21-2189-2024, 2024
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The timing of the net primary production annual maxima in the North Atlantic in the period 1750–2100 is investigated using two Earth system models and the high-emissions scenario SSP5-8.5. It is found that, for most of the region, the annual maxima occur progressively earlier, with the most change occurring after the year 2000. Shifts in the seasonality of the primary production may impact the entire ecosystem, which highlights the need for long-term monitoring campaigns in this area.
Nicole M. Travis, Colette L. Kelly, and Karen L. Casciotti
Biogeosciences, 21, 1985–2004, https://doi.org/10.5194/bg-21-1985-2024, https://doi.org/10.5194/bg-21-1985-2024, 2024
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We conducted experimental manipulations of light level on microbial communities from the primary nitrite maximum. Overall, while individual microbial processes have different directions and magnitudes in their response to increasing light, the net community response is a decline in nitrite production with increasing light. We conclude that while increased light may decrease net nitrite production, high-light conditions alone do not exclude nitrification from occurring in the surface ocean.
Zoë Rebecca van Kemenade, Zeynep Erdem, Ellen Christine Hopmans, Jaap Smede Sinninghe Damsté, and Darci Rush
Biogeosciences, 21, 1517–1532, https://doi.org/10.5194/bg-21-1517-2024, https://doi.org/10.5194/bg-21-1517-2024, 2024
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The California Current system (CCS) hosts the eastern subtropical North Pacific oxygen minimum zone (ESTNP OMZ). This study shows anaerobic ammonium oxidizing (anammox) bacteria cause a loss of bioavailable nitrogen (N) in the ESTNP OMZ throughout the late Quaternary. Anammox occurred during both glacial and interglacial periods and was driven by the supply of organic matter and changes in ocean currents. These findings may have important consequences for biogeochemical models of the CCS.
Cathy Wimart-Rousseau, Tobias Steinhoff, Birgit Klein, Henry Bittig, and Arne Körtzinger
Biogeosciences, 21, 1191–1211, https://doi.org/10.5194/bg-21-1191-2024, https://doi.org/10.5194/bg-21-1191-2024, 2024
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The marine CO2 system can be measured independently and continuously by BGC-Argo floats since numerous pH sensors have been developed to suit these autonomous measurements platforms. By applying the Argo correction routines to float pH data acquired in the subpolar North Atlantic Ocean, we report the uncertainty and lack of objective criteria associated with the choice of the reference method as well the reference depth for the pH correction.
Sabine Mecking and Kyla Drushka
Biogeosciences, 21, 1117–1133, https://doi.org/10.5194/bg-21-1117-2024, https://doi.org/10.5194/bg-21-1117-2024, 2024
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This study investigates whether northeastern North Pacific oxygen changes may be caused by surface density changes in the northwest as water moves along density horizons from the surface into the subsurface ocean. A correlation is found with a lag that about matches the travel time of water from the northwest to the northeast. Salinity is the main driver causing decadal changes in surface density, whereas salinity and temperature contribute about equally to long-term declining density trends.
Takamitsu Ito, Hernan E. Garcia, Zhankun Wang, Shoshiro Minobe, Matthew C. Long, Just Cebrian, James Reagan, Tim Boyer, Christopher Paver, Courtney Bouchard, Yohei Takano, Seth Bushinsky, Ahron Cervania, and Curtis A. Deutsch
Biogeosciences, 21, 747–759, https://doi.org/10.5194/bg-21-747-2024, https://doi.org/10.5194/bg-21-747-2024, 2024
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This study aims to estimate how much oceanic oxygen has been lost and its uncertainties. One major source of uncertainty comes from the statistical gap-filling methods. Outputs from Earth system models are used to generate synthetic observations where oxygen data are extracted from the model output at the location and time of historical oceanographic cruises. Reconstructed oxygen trend is approximately two-thirds of the true trend.
Robert W. Izett, Katja Fennel, Adam C. Stoer, and David P. Nicholson
Biogeosciences, 21, 13–47, https://doi.org/10.5194/bg-21-13-2024, https://doi.org/10.5194/bg-21-13-2024, 2024
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This paper provides an overview of the capacity to expand the global coverage of marine primary production estimates using autonomous ocean-going instruments, called Biogeochemical-Argo floats. We review existing approaches to quantifying primary production using floats, provide examples of the current implementation of the methods, and offer insights into how they can be better exploited. This paper is timely, given the ongoing expansion of the Biogeochemical-Argo array.
Qian Liu, Yingjie Liu, and Xiaofeng Li
Biogeosciences, 20, 4857–4874, https://doi.org/10.5194/bg-20-4857-2023, https://doi.org/10.5194/bg-20-4857-2023, 2023
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In the Southern Ocean, abundant eddies behave opposite to our expectations. That is, anticyclonic (cyclonic) eddies are cold (warm). By investigating the variations of physical and biochemical parameters in eddies, we find that abnormal eddies have unique and significant effects on modulating the parameters. This study fills a gap in understanding the effects of abnormal eddies on physical and biochemical parameters in the Southern Ocean.
Caroline Ulses, Claude Estournel, Patrick Marsaleix, Karline Soetaert, Marine Fourrier, Laurent Coppola, Dominique Lefèvre, Franck Touratier, Catherine Goyet, Véronique Guglielmi, Fayçal Kessouri, Pierre Testor, and Xavier Durrieu de Madron
Biogeosciences, 20, 4683–4710, https://doi.org/10.5194/bg-20-4683-2023, https://doi.org/10.5194/bg-20-4683-2023, 2023
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Deep convection plays a key role in the circulation, thermodynamics, and biogeochemical cycles in the Mediterranean Sea, considered to be a hotspot of biodiversity and climate change. In this study, we investigate the seasonal and annual budget of dissolved inorganic carbon in the deep-convection area of the northwestern Mediterranean Sea.
Daniela König and Alessandro Tagliabue
Biogeosciences, 20, 4197–4212, https://doi.org/10.5194/bg-20-4197-2023, https://doi.org/10.5194/bg-20-4197-2023, 2023
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Using model simulations, we show that natural and anthropogenic changes in the global climate leave a distinct fingerprint in the isotopic signatures of iron in the surface ocean. We find that these climate effects on iron isotopes are often caused by the redistribution of iron from different external sources to the ocean, due to changes in ocean currents, and by changes in algal growth, which take up iron. Thus, isotopes may help detect climate-induced changes in iron supply and algal uptake.
Chloé Baumas, Robin Fuchs, Marc Garel, Jean-Christophe Poggiale, Laurent Memery, Frédéric A. C. Le Moigne, and Christian Tamburini
Biogeosciences, 20, 4165–4182, https://doi.org/10.5194/bg-20-4165-2023, https://doi.org/10.5194/bg-20-4165-2023, 2023
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Through the sink of particles in the ocean, carbon (C) is exported and sequestered when reaching 1000 m. Attempts to quantify C exported vs. C consumed by heterotrophs have increased. Yet most of the conducted estimations have led to C demands several times higher than C export. The choice of parameters greatly impacts the results. As theses parameters are overlooked, non-accurate values are often used. In this study we show that C budgets can be well balanced when using appropriate values.
Anna Belcher, Sian F. Henley, Katharine Hendry, Marianne Wootton, Lisa Friberg, Ursula Dallman, Tong Wang, Christopher Coath, and Clara Manno
Biogeosciences, 20, 3573–3591, https://doi.org/10.5194/bg-20-3573-2023, https://doi.org/10.5194/bg-20-3573-2023, 2023
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The oceans play a crucial role in the uptake of atmospheric carbon dioxide, particularly the Southern Ocean. The biological pumping of carbon from the surface to the deep ocean is key to this. Using sediment trap samples from the Scotia Sea, we examine biogeochemical fluxes of carbon, nitrogen, and biogenic silica and their stable isotope compositions. We find phytoplankton community structure and physically mediated processes are important controls on particulate fluxes to the deep ocean.
Asmita Singh, Susanne Fietz, Sandy J. Thomalla, Nicolas Sanchez, Murat V. Ardelan, Sébastien Moreau, Hanna M. Kauko, Agneta Fransson, Melissa Chierici, Saumik Samanta, Thato N. Mtshali, Alakendra N. Roychoudhury, and Thomas J. Ryan-Keogh
Biogeosciences, 20, 3073–3091, https://doi.org/10.5194/bg-20-3073-2023, https://doi.org/10.5194/bg-20-3073-2023, 2023
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Despite the scarcity of iron in the Southern Ocean, seasonal blooms occur due to changes in nutrient and light availability. Surprisingly, during an autumn bloom in the Antarctic sea-ice zone, the results from incubation experiments showed no significant photophysiological response of phytoplankton to iron addition. This suggests that ambient iron concentrations were sufficient, challenging the notion of iron deficiency in the Southern Ocean through extended iron-replete post-bloom conditions.
Benoît Pasquier, Mark Holzer, Matthew A. Chamberlain, Richard J. Matear, Nathaniel L. Bindoff, and François W. Primeau
Biogeosciences, 20, 2985–3009, https://doi.org/10.5194/bg-20-2985-2023, https://doi.org/10.5194/bg-20-2985-2023, 2023
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Modeling the ocean's carbon and oxygen cycles accurately is challenging. Parameter optimization improves the fit to observed tracers but can introduce artifacts in the biological pump. Organic-matter production and subsurface remineralization rates adjust to compensate for circulation biases, changing the pathways and timescales with which nutrients return to the surface. Circulation biases can thus strongly alter the system’s response to ecological change, even when parameters are optimized.
Priyanka Banerjee
Biogeosciences, 20, 2613–2643, https://doi.org/10.5194/bg-20-2613-2023, https://doi.org/10.5194/bg-20-2613-2023, 2023
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This study shows that atmospheric deposition is the most important source of iron to the upper northern Indian Ocean for phytoplankton growth. This is followed by iron from continental-shelf sediment. Phytoplankton increase following iron addition is possible only with high background levels of nitrate. Vertical mixing is the most important physical process supplying iron to the upper ocean in this region throughout the year. The importance of ocean currents in supplying iron varies seasonally.
Iris Kriest, Julia Getzlaff, Angela Landolfi, Volkmar Sauerland, Markus Schartau, and Andreas Oschlies
Biogeosciences, 20, 2645–2669, https://doi.org/10.5194/bg-20-2645-2023, https://doi.org/10.5194/bg-20-2645-2023, 2023
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Global biogeochemical ocean models are often subjectively assessed and tuned against observations. We applied different strategies to calibrate a global model against observations. Although the calibrated models show similar tracer distributions at the surface, they differ in global biogeochemical fluxes, especially in global particle flux. Simulated global volume of oxygen minimum zones varies strongly with calibration strategy and over time, rendering its temporal extrapolation difficult.
John C. Tracey, Andrew R. Babbin, Elizabeth Wallace, Xin Sun, Katherine L. DuRussel, Claudia Frey, Donald E. Martocello III, Tyler Tamasi, Sergey Oleynik, and Bess B. Ward
Biogeosciences, 20, 2499–2523, https://doi.org/10.5194/bg-20-2499-2023, https://doi.org/10.5194/bg-20-2499-2023, 2023
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Nitrogen (N) is essential for life; thus, its availability plays a key role in determining marine productivity. Using incubations of seawater spiked with a rare form of N measurable on a mass spectrometer, we quantified microbial pathways that determine marine N availability. The results show that pathways that recycle N have higher rates than those that result in its loss from biomass and present new evidence for anaerobic nitrite oxidation, a process long thought to be strictly aerobic.
Amanda Gerotto, Hongrui Zhang, Renata Hanae Nagai, Heather M. Stoll, Rubens César Lopes Figueira, Chuanlian Liu, and Iván Hernández-Almeida
Biogeosciences, 20, 1725–1739, https://doi.org/10.5194/bg-20-1725-2023, https://doi.org/10.5194/bg-20-1725-2023, 2023
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Based on the analysis of the response of coccolithophores’ morphological attributes in a laboratory dissolution experiment and surface sediment samples from the South China Sea, we proposed that the thickness shape (ks) factor of fossil coccoliths together with the normalized ks variation, which is the ratio of the standard deviation of ks (σ) over the mean ks (σ/ks), is a robust and novel proxy to reconstruct past changes in deep ocean carbon chemistry.
Katherine E. Turner, Doug M. Smith, Anna Katavouta, and Richard G. Williams
Biogeosciences, 20, 1671–1690, https://doi.org/10.5194/bg-20-1671-2023, https://doi.org/10.5194/bg-20-1671-2023, 2023
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We present a new method for reconstructing ocean carbon using climate models and temperature and salinity observations. To test this method, we reconstruct modelled carbon using synthetic observations consistent with current sampling programmes. Sensitivity tests show skill in reconstructing carbon trends and variability within the upper 2000 m. Our results indicate that this method can be used for a new global estimate for ocean carbon content.
Alexandre Mignot, Hervé Claustre, Gianpiero Cossarini, Fabrizio D'Ortenzio, Elodie Gutknecht, Julien Lamouroux, Paolo Lazzari, Coralie Perruche, Stefano Salon, Raphaëlle Sauzède, Vincent Taillandier, and Anna Teruzzi
Biogeosciences, 20, 1405–1422, https://doi.org/10.5194/bg-20-1405-2023, https://doi.org/10.5194/bg-20-1405-2023, 2023
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Numerical models of ocean biogeochemistry are becoming a major tool to detect and predict the impact of climate change on marine resources and monitor ocean health. Here, we demonstrate the use of the global array of BGC-Argo floats for the assessment of biogeochemical models. We first detail the handling of the BGC-Argo data set for model assessment purposes. We then present 23 assessment metrics to quantify the consistency of BGC model simulations with respect to BGC-Argo data.
Alban Planchat, Lester Kwiatkowski, Laurent Bopp, Olivier Torres, James R. Christian, Momme Butenschön, Tomas Lovato, Roland Séférian, Matthew A. Chamberlain, Olivier Aumont, Michio Watanabe, Akitomo Yamamoto, Andrew Yool, Tatiana Ilyina, Hiroyuki Tsujino, Kristen M. Krumhardt, Jörg Schwinger, Jerry Tjiputra, John P. Dunne, and Charles Stock
Biogeosciences, 20, 1195–1257, https://doi.org/10.5194/bg-20-1195-2023, https://doi.org/10.5194/bg-20-1195-2023, 2023
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Ocean alkalinity is critical to the uptake of atmospheric carbon and acidification in surface waters. We review the representation of alkalinity and the associated calcium carbonate cycle in Earth system models. While many parameterizations remain present in the latest generation of models, there is a general improvement in the simulated alkalinity distribution. This improvement is related to an increase in the export of biotic calcium carbonate, which closer resembles observations.
Jérôme Pinti, Tim DeVries, Tommy Norin, Camila Serra-Pompei, Roland Proud, David A. Siegel, Thomas Kiørboe, Colleen M. Petrik, Ken H. Andersen, Andrew S. Brierley, and André W. Visser
Biogeosciences, 20, 997–1009, https://doi.org/10.5194/bg-20-997-2023, https://doi.org/10.5194/bg-20-997-2023, 2023
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Large numbers of marine organisms such as zooplankton and fish perform daily vertical migration between the surface (at night) and the depths (in the daytime). This fascinating migration is important for the carbon cycle, as these organisms actively bring carbon to depths where it is stored away from the atmosphere for a long time. Here, we quantify the contributions of different animals to this carbon drawdown and storage and show that fish are important to the biological carbon pump.
Alastair J. M. Lough, Alessandro Tagliabue, Clément Demasy, Joseph A. Resing, Travis Mellett, Neil J. Wyatt, and Maeve C. Lohan
Biogeosciences, 20, 405–420, https://doi.org/10.5194/bg-20-405-2023, https://doi.org/10.5194/bg-20-405-2023, 2023
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Iron is a key nutrient for ocean primary productivity. Hydrothermal vents are a source of iron to the oceans, but the size of this source is poorly understood. This study examines the variability in iron inputs between hydrothermal vents in different geological settings. The vents studied release different amounts of Fe, resulting in plumes with similar dissolved iron concentrations but different particulate concentrations. This will help to refine modelling of iron-limited ocean productivity.
Nicole M. Travis, Colette L. Kelly, Margaret R. Mulholland, and Karen L. Casciotti
Biogeosciences, 20, 325–347, https://doi.org/10.5194/bg-20-325-2023, https://doi.org/10.5194/bg-20-325-2023, 2023
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The primary nitrite maximum is a ubiquitous upper ocean feature where nitrite accumulates, but we still do not understand its formation and the co-occurring microbial processes involved. Using correlative methods and rates measurements, we found strong spatial patterns between environmental conditions and depths of the nitrite maxima, but not the maximum concentrations. Nitrification was the dominant source of nitrite, with occasional high nitrite production from phytoplankton near the coast.
Natacha Le Grix, Jakob Zscheischler, Keith B. Rodgers, Ryohei Yamaguchi, and Thomas L. Frölicher
Biogeosciences, 19, 5807–5835, https://doi.org/10.5194/bg-19-5807-2022, https://doi.org/10.5194/bg-19-5807-2022, 2022
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Compound events threaten marine ecosystems. Here, we investigate the potentially harmful combination of marine heatwaves with low phytoplankton productivity. Using satellite-based observations, we show that these compound events are frequent in the low latitudes. We then investigate the drivers of these compound events using Earth system models. The models share similar drivers in the low latitudes but disagree in the high latitudes due to divergent factors limiting phytoplankton production.
Abigale M. Wyatt, Laure Resplandy, and Adrian Marchetti
Biogeosciences, 19, 5689–5705, https://doi.org/10.5194/bg-19-5689-2022, https://doi.org/10.5194/bg-19-5689-2022, 2022
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Marine heat waves (MHWs) are a frequent event in the northeast Pacific, with a large impact on the region's ecosystems. Large phytoplankton in the North Pacific Transition Zone are greatly affected by decreased nutrients, with less of an impact in the Alaskan Gyre. For small phytoplankton, MHWs increase the spring small phytoplankton population in both regions thanks to reduced light limitation. In both zones, this results in a significant decrease in the ratio of large to small phytoplankton.
Margot C. F. Debyser, Laetitia Pichevin, Robyn E. Tuerena, Paul A. Dodd, Antonia Doncila, and Raja S. Ganeshram
Biogeosciences, 19, 5499–5520, https://doi.org/10.5194/bg-19-5499-2022, https://doi.org/10.5194/bg-19-5499-2022, 2022
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We focus on the exchange of key nutrients for algae production between the Arctic and Atlantic oceans through the Fram Strait. We show that the export of dissolved silicon here is controlled by the availability of nitrate which is influenced by denitrification on Arctic shelves. We suggest that any future changes in the river inputs of silica and changes in denitrification due to climate change will impact the amount of silicon exported, with impacts on Atlantic algal productivity and ecology.
Emily J. Zakem, Barbara Bayer, Wei Qin, Alyson E. Santoro, Yao Zhang, and Naomi M. Levine
Biogeosciences, 19, 5401–5418, https://doi.org/10.5194/bg-19-5401-2022, https://doi.org/10.5194/bg-19-5401-2022, 2022
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We use a microbial ecosystem model to quantitatively explain the mechanisms controlling observed relative abundances and nitrification rates of ammonia- and nitrite-oxidizing microorganisms in the ocean. We also estimate how much global carbon fixation can be associated with chemoautotrophic nitrification. Our results improve our understanding of the controls on nitrification, laying the groundwork for more accurate predictions in global climate models.
Zuozhu Wen, Thomas J. Browning, Rongbo Dai, Wenwei Wu, Weiying Li, Xiaohua Hu, Wenfang Lin, Lifang Wang, Xin Liu, Zhimian Cao, Haizheng Hong, and Dalin Shi
Biogeosciences, 19, 5237–5250, https://doi.org/10.5194/bg-19-5237-2022, https://doi.org/10.5194/bg-19-5237-2022, 2022
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Fe and P are key factors controlling the biogeography and activity of marine N2-fixing microorganisms. We found lower abundance and activity of N2 fixers in the northern South China Sea than around the western boundary of the North Pacific, and N2 fixation rates switched from Fe–P co-limitation to P limitation. We hypothesize the Fe supply rates and Fe utilization strategies of each N2 fixer are important in regulating spatial variability in community structure across the study area.
Claudia Eisenring, Sophy E. Oliver, Samar Khatiwala, and Gregory F. de Souza
Biogeosciences, 19, 5079–5106, https://doi.org/10.5194/bg-19-5079-2022, https://doi.org/10.5194/bg-19-5079-2022, 2022
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Given the sparsity of observational constraints on micronutrients such as zinc (Zn), we assess the sensitivities of a framework for objective parameter optimisation in an oceanic Zn cycling model. Our ensemble of optimisations towards synthetic data with varying kinds of uncertainty shows that deficiencies related to model complexity and the choice of the misfit function generally have a greater impact on the retrieval of model Zn uptake behaviour than does the limitation of data coverage.
Yoshikazu Sasai, Sherwood Lan Smith, Eko Siswanto, Hideharu Sasaki, and Masami Nonaka
Biogeosciences, 19, 4865–4882, https://doi.org/10.5194/bg-19-4865-2022, https://doi.org/10.5194/bg-19-4865-2022, 2022
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We have investigated the adaptive response of phytoplankton growth to changing light, nutrients, and temperature over the North Pacific using two physical-biological models. We compare modeled chlorophyll and primary production from an inflexible control model (InFlexPFT), which assumes fixed carbon (C):nitrogen (N):chlorophyll (Chl) ratios, to a recently developed flexible phytoplankton functional type model (FlexPFT), which incorporates photoacclimation and variable C:N:Chl ratios.
Jens Terhaar, Thomas L. Frölicher, and Fortunat Joos
Biogeosciences, 19, 4431–4457, https://doi.org/10.5194/bg-19-4431-2022, https://doi.org/10.5194/bg-19-4431-2022, 2022
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Estimates of the ocean sink of anthropogenic carbon vary across various approaches. We show that the global ocean carbon sink can be estimated by three parameters, two of which approximate the ocean ventilation in the Southern Ocean and the North Atlantic, and one of which approximates the chemical capacity of the ocean to take up carbon. With observations of these parameters, we estimate that the global ocean carbon sink is 10 % larger than previously assumed, and we cut uncertainties in half.
Natasha René van Horsten, Hélène Planquette, Géraldine Sarthou, Thomas James Ryan-Keogh, Nolwenn Lemaitre, Thato Nicholas Mtshali, Alakendra Roychoudhury, and Eva Bucciarelli
Biogeosciences, 19, 3209–3224, https://doi.org/10.5194/bg-19-3209-2022, https://doi.org/10.5194/bg-19-3209-2022, 2022
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The remineralisation proxy, barite, was measured along 30°E in the southern Indian Ocean during early austral winter. To our knowledge this is the first reported Southern Ocean winter study. Concentrations throughout the water column were comparable to observations during spring to autumn. By linking satellite primary production to this proxy a possible annual timescale is proposed. These findings also suggest possible carbon remineralisation from satellite data on a basin scale.
Zhibo Shao and Ya-Wei Luo
Biogeosciences, 19, 2939–2952, https://doi.org/10.5194/bg-19-2939-2022, https://doi.org/10.5194/bg-19-2939-2022, 2022
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Non-cyanobacterial diazotrophs (NCDs) may be an important player in fixing N2 in the ocean. By conducting meta-analyses, we found that a representative marine NCD phylotype, Gamma A, tends to inhabit ocean environments with high productivity, low iron concentration and high light intensity. It also appears to be more abundant inside cyclonic eddies. Our study suggests a niche differentiation of NCDs from cyanobacterial diazotrophs as the latter prefers low-productivity and high-iron oceans.
Coraline Leseurre, Claire Lo Monaco, Gilles Reverdin, Nicolas Metzl, Jonathan Fin, Claude Mignon, and Léa Benito
Biogeosciences, 19, 2599–2625, https://doi.org/10.5194/bg-19-2599-2022, https://doi.org/10.5194/bg-19-2599-2022, 2022
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Decadal trends of fugacity of CO2 (fCO2), total alkalinity (AT), total carbon (CT) and pH in surface waters are investigated in different domains of the southern Indian Ocean (45°S–57°S) from ongoing and station observations regularly conducted in summer over the period 1998–2019. The fCO2 increase and pH decrease are mainly driven by anthropogenic CO2 estimated just below the summer mixed layer, as well as by a warming south of the polar front or in the fertilized waters near Kerguelen Island.
Priscilla Le Mézo, Jérôme Guiet, Kim Scherrer, Daniele Bianchi, and Eric Galbraith
Biogeosciences, 19, 2537–2555, https://doi.org/10.5194/bg-19-2537-2022, https://doi.org/10.5194/bg-19-2537-2022, 2022
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This study quantifies the role of commercially targeted fish biomass in the cycling of three important nutrients (N, P, and Fe), relative to nutrients otherwise available in water and to nutrients required by primary producers, and the impact of fishing. We use a model of commercially targeted fish biomass constrained by fish catch and stock assessment data to assess the contributions of fish at the global scale, at the time of the global peak catch and prior to industrial fishing.
Cited articles
Bagniewski, W., Fennel, K., Perry, M. J., and D'Asaro, E. A.: Optimizing models of the North Atlantic spring bloom using physical, chemical and bio-optical observations from a Lagrangian float, Biogeosciences, 8, 1291–1307, https://doi.org/10.5194/bg-8-1291-2011, 2011. a, b, c
Behrenfeld, M. J., Boss, E., Siegel, D. A., and Shea, D. M.: Carbon-based
ocean productivity and phytoplankton physiology from space, Global Biogeochem. Cy., 19, 1–14, https://doi.org/10.1029/2004GB002299, 2005. a
Boss, E. B. and Haëntjens, N.: Primer regarding measurements of chlorophyll fluorescence and the backscattering coefficient with WETLabs FLBB on profiling floats, SOCCOM Tech. Rep. 2016-1, available at: http://soccom.princeton.edu/sites/default/files/files/SOCCOM_2016-1_Bio-optics-primer.pdf (last access: 29 July 2018), 2016. a
Briggs, N., Perry, M. J., Cetinic´, I., Lee, C., D'Asaro, E., Gray, A. M., and
Rehm, E.: High-resolution observations of aggregate flux during a sub-polar
North Atlantic spring bloom, Deep-Sea Res. Pt. I, 58, 1031–1039,
https://doi.org/10.1016/j.dsr.2011.07.007, 2011. a
Chassignet, E. P., Hurlburt, H. E., Metzger, E. J., Smedstad, O., Cummings, J., Halliwell, G., Bleck, R., Baraille, R.,Wallcraft, A. J., Lozano, C., Tolman, H. L., Srinivasan, A., Hankin, S., Cornillon, P., Weisberg, R., Barth, A., He, R., Werner, F., and Wilkin, J.: US GODAE: Global ocean prediction with the HYbrid Coordinate Ocean Model (HYCOM), Oceanography, 22, 64–75, https://doi.org/10.5670/oceanog.2009.39, 2009.
Cullen, J. J.: Subsurface Chlorophyll Maximum Layers: Enduring Enigma or
Mystery Solved ?, Annu. Rev. Mar. Sci., 7, 207–239,
https://doi.org/10.1146/annurev-marine-010213-135111, 2015. a, b, c
Doney, S. C., Lima, I., Moore, J. K., Lindsay, K., Behrenfeld, M. J.,
Westberry, T. K., Mahowald, N., Glover, D. M., and Takahashi, T.: Skill
metrics for confronting global upper ocean ecosystem-biogeochemistry models
against field and remote sensing data, J. Marine Syst., 76,
95–112, https://doi.org/10.1016/j.jmarsys.2008.05.015, 2009. a
Fennel, K., Wilkin, J., Levin, J., Moisan, J., Reilly, J. O., and Haidvogel,
D.: Nitrogen cycling in the Middle Atlantic Bight: Results from a
three-dimensional model and implications for the North Atlantic nitrogen
budget, Global Biogeochem. Cy., 20, 1–14, https://doi.org/10.1029/2005GB002456,
2006. a, b, c
Fennel, K., Hetland, R., Feng, Y., and DiMarco, S.: A coupled physical-biological model of the Northern Gulf of Mexico shelf: model description, validation and analysis of phytoplankton variability, Biogeosciences, 8, 1881–1899, https://doi.org/10.5194/bg-8-1881-2011, 2011. a, b, c
Friedrichs, M. A. M., Hood, R. R., and Wiggert, J. D.: Ecosystem model
complexity versus physical forcing: Quantification of their relative impact
with assimilated Arabian Sea data, Deep-Sea Res. Pt. II, 53, 576–600,
https://doi.org/10.1016/j.dsr2.2006.01.026, 2006. a, b, c
Friedrichs, M. A. M., Dusenberry, J. A., Anderson, L. A., Armstrong, R. A.,
Chai, F., Christian, J. R., Doney, S. C., Dunne, J., Fujii, M., Hood, R., Jr,
D. J. M., Moore, J. K., Schartau, M., Spitz, Y. H., and Wiggert, J. D.:
Assessment of skill and portability in regional marine biogeochemical
models: Role of multiple planktonic groups, J. Geophys. Res.,
112, 1–22, https://doi.org/10.1029/2006JC003852, 2007. a, b
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. a
Gomez, F. A., Lee, S.-K., Liu, Y., Hernandez Jr., F. J., Muller-Karger, F. E., and Lamkin, J. T.: Seasonal patterns in phytoplankton biomass across the northern and deep Gulf of Mexico: a numerical model study, Biogeosciences, 15, 3561–3576, https://doi.org/10.5194/bg-15-3561-2018, 2018. a
Green, R. E., Bower, A. S., and Lugo-Fernandez, A.: First Autonomous
Bio-Optical Profiling Float in the Gulf of Mexico Reveals Dynamic
Biogeochemistry in Deep Waters, PLOS ONE, 9, 1–9,
https://doi.org/10.1371/journal.pone.0101658, 2014. a, b, c
Group, B.-A. P.: The scientific rationale, design and implementation plan for a
Biogeochemical-Argo float array, Report,
https://doi.org/10.13155/46601, 2016. a
Haidvogel, D. B., Arango, H., Budgell, W. P., Cornuelle, B. D., Curchitser, E.,
Lorenzo, E. D., Fennel, K., Geyer, W., Hermann, A., Lanerolle, L., Levin, J.,
McWilliams, J. C., Miller, A. J., Moore, A. M., Powell, T. M., Shchepetkin,
A. F., Sherwood, C. R., Signell, R. P., Warner, J. C., and Wilkin, J.: Ocean
forecasting in terrain-following coordinates: Formulation and skill
assessment of the Regional Ocean Modeling System, J. Comput. Phys., 227, 3595–3624, https://doi.org/10.1016/j.jcp.2007.06.016, 2008. a
Hamilton, P. and Leidos: Ocean currents, temperatures, and others measured by drifters and profiling floats for the Lagrangian Approach to Study the
Gulf of Mexico Deep Circulation project 2011-07 to 2015-06 (NCEI Accession
0159562), Version 1.1, NOAA National Centers for Environmental Information,
Dataset, available at: https://accession.nodc.noaa.gov/0159562 (last access: 25 October 2017), Tech. rep., 2017. a
Henson, S. A., Sanders, R., and Madsen, E.: Global patterns in efficiency of
particulate organic carbon export and transfer to the deep ocean, Global Biogeochem. Cy., 26, 1–14, https://doi.org/10.1029/2011GB004099,
2012. a
Henson, S. A., Yool, A., and Sanders, R.: Variability in efficiency of
particulate organic carbon export: A model study, Global Biogeochem. Cy., 29, 33–45, https://doi.org/10.1002/2014GB004965,
2015. a
Hoshiba, Y., Hirata, T., Shigemitsu, M., Nakano, H., Hashioka, T., Masuda, Y.,
and Yamanaka, Y.: Biological data assimilation for parameter estimation of a
phytoplankton functional type model for the western North Pacific, Ocean Sci., 14, 371–386, https://doi.org/10.5194/os-14-371-2018, 2018. a, b, c, d
Hung, C.-C., Xu, C., Santschi, P. H., Zhang, S.-J., Schwehr, K. A., Quigg, A.,
Guo, L., Gong, G.-C., Pinckney, J. L., Long, R. A., and Wei, C.-L.:
Comparative evaluation of sediment trap and 234Th-derived POC fluxes from
the upper oligotrophic waters of the Gulf of Mexico and the subtropical
northwestern Pacific Ocean, Mar. Chem., 121, 132–144,
https://doi.org/10.1016/j.marchem.2010.03.011,
2010. a
Kane, A., Moulin, C., Thiria, S., Bopp, L., Berrada, M., Tagliabue, A.,
Crépon, M., Aumont, O., and Badran, F.: Improving the parameters of a
global ocean biogeochemical model via variational assimilation of in situ
data at five time series stations, J. Geophys. Res.-Oceans,
116, 1–14, https://doi.org/10.1029/2009JC006005, 2011. a, b, c, d, e
Kidston, M., Matear, R., and Baird, M. E.: Parameter optimisation of a marine
ecosystem model at two contrasting stations in the Sub-Antarctic Zone,
Deep-Sea Res. Pt. II, 58, 2301–2315, https://doi.org/10.1016/j.dsr2.2011.05.018, 2011. a
Kuhn, A. M. and Fennel, K.: Evaluating ecosystem model complexity for the
northwest North Atlantic through surrogate-based optimization, Ocean Model., 142, 101 437, https://doi.org/10.1016/j.ocemod.2019.101437,
2019. a, b, c
Kuhn, A. M., Fennel, K., and Mattern, J. P.: Progress in Oceanography Model
investigations of the North Atlantic spring bloom initiation, Prog. Oceanogr., 138, 176–193, https://doi.org/10.1016/j.pocean.2015.07.004, 2015. a, b, c, d
Kuhn, A. M., Fennel, K., and Berman-Frank, I.: Modelling the biogeochemical effects of heterotrophic and autotrophic N2 fixation in the Gulf of Aqaba (Israel), Red Sea, Biogeosciences, 15, 7379–7401, https://doi.org/10.5194/bg-15-7379-2018, 2018. a, b, c
Lagman, K. B., Fennel, K., Thompson, K. R., and Bianucci, L.: Assessing the
utility of frequency dependent nudging for reducing biases in biogeochemical
models, Ocean Model., 81, 25–35,
https://doi.org/10.1016/j.ocemod.2014.06.006,
2014. a
Laurent, A., Fennel, K., Cai, W. J., Huang, W. J., Barbero, L., and Wanninkhof,
R.: Eutrophication-induced acidification of coastal waters in the northern
Gulf of Mexico: Insights into origin and processes from a coupled
physical-biogeochemical model, Geophys. Res. Lett., 44, 946–956,
https://doi.org/10.1002/2016GL071881, 2017. a, b
Laws, E. A., Falkowski, P. G., Smith Jr., W. O., Ducklow, H., and McCarthy,
J. J.: Temperature effects on export production in the open ocean, Global Biogeochem. Cy., 14, 1231–1246, https://doi.org/10.1029/1999GB001229,
2000. a
Lehmann, M. K., Fennel, K., and He, R.: Statistical validation of a 3-D bio-physical model of the western North Atlantic, Biogeosciences, 6, 1961–1974, https://doi.org/10.5194/bg-6-1961-2009, 2009. a
Lima, I. D., Lam, P. J., and Doney, S. C.: Dynamics of particulate organic carbon flux in a global ocean model, Biogeosciences, 11, 1177–1198, https://doi.org/10.5194/bg-11-1177-2014, 2014. a
Martínez-López, B. and Zavala-Hidalgo, J.: Seasonal and
interannual variability of cross-shelf transports of chlorophyll in the Gulf
of Mexico, J. Marine Syst., 77, 1–20,
https://doi.org/10.1016/j.jmarsys.2008.10.002, 2009. a
Martinez-Vicente, V., Dall'Olmo, G., Tarran, G., Boss, E., and Sathyendranath,
S.: Optical backscattering is correlated with phytoplankton carbon across
the Atlantic Ocean, Geophys. Res. Lett., 40, 1154–1158,
https://doi.org/10.1002/grl.50252, 2013. a
Mattern, J. P. and Edwards, C. A.: Simple parameter estimation for complex
models – Testing evolutionary techniques on 3-dimensional biogeochemical
ocean models, J. Marine Syst., 165, 139–152,
https://doi.org/10.1016/j.jmarsys.2016.10.012, 2017. a
Mattern, J. P., Fennel, K., and Dowd, M.: Estimating time-dependent parameters
for a biological ocean model using an emulator approach, J. Marine Syst., 96-97, 32–47, https://doi.org/10.1016/j.jmarsys.2012.01.015,
2012. a, b
Mellor, G. L. and Yamada, T.: Development of a turbulence closure model for
geophysical fluid problems, Rev. Geophys. Space Ge., 20,
851–875, https://doi.org/10.1029/RG020i004p00851, 1982. a
Mignot, A., Claustre, H., Uitz, J., Poteau, A., D'Ortenzio, F., and Xing, X.:
Understanding the seasonal dynamics of phytoplankton biomass and the deep
chlorophyll maximum in oligotrophic environments: A Bio-Argo float
investigation, Global Biogeochem. Cy., 28, 1–21,
https://doi.org/10.1002/2013GB004781, 2014. a
Muller-Karger, F. E., Walsh, J. J., Evans, R. H., and Meyers, M. B.: On the
Seasonal Phytoplankton Concentration and Sea Surface Temperature Cycles of
the Gulf of Mexico as Determined by Satellites, J. Geophys. Res., 96, 12 645–12 665, 1991. a
Muller-Karger, F. E., Smith, J. P., Werner, S., Chen, R., Roffer, M., Liu, Y.,
Muhling, B., Lindo-atichati, D., Lamkin, J., Cerdeira-estrada, S., and
Enfield, D. B.: Natural variability of surface oceanographic conditions in
the offshore Gulf of Mexico, Prog. Oceanogr., 134, 54–76,
https://doi.org/10.1016/j.pocean.2014.12.007, 2015. a
Pasqueron de Fommervault, O., Perez-Brunius, P., Damien, P., Camacho-Ibar, V. F., and Sheinbaum, J.: Temporal variability of chlorophyll distribution in the Gulf of Mexico: bio-optical data from profiling floats, Biogeosciences, 14, 5647–5662, https://doi.org/10.5194/bg-14-5647-2017, 2017. a, b, c, d
Rasse, R., Dall'Olmo, G., Graff, J., Westberry, T. K., van Dongen-Vogels, V.,
and Behrenfeld, M. J.: Evaluating Optical Proxies of Particulate Organic
Carbon across the Surface Atlantic Ocean, Frontiers in Marine Science, 4,
1–18, https://doi.org/10.3389/fmars.2017.00367, 2017. a
Roemmich, D., Alford, M. H., Claustre, H., Johnson, K., King, B., Moum, J.,
Oke, P., Owens, W. B., Pouliquen, S., Purkey, S., Scanderbeg, M., Suga, T.,
Wijffels, S., Zilberman, N., Bakker, D., Baringer, M., Belbeoch, M., Bittig,
H. C., Boss, E., Calil, P., Carse, F., Carval, T., Chai, F., Conchubhair,
D. Ó., D'Ortenzio, F., Dall'Olmo, G., Desbruyeres, D., Fennel, K., Fer,
I., Ferrari, R., Forget, G., Freeland, H., Fujiki, T., Gehlen, M., Greenan,
B., Hallberg, R., Hibiya, T., Hosoda, S., Jayne, S., Jochum, M., Johnson,
G. C., Kang, K., Kolodziejczyk, N., Körtzinger, A., Traon, P.-Y. L.,
Lenn, Y.-D., Maze, G., Mork, K. A., Morris, T., Nagai, T., Nash, J.,
Garabato, A. N., Olsen, A., Pattabhi, R. R., Prakash, S., Riser, S.,
Schmechtig, C., Schmid, C., Shroyer, E., Sterl, A., Sutton, P., Talley, L.,
Tanhua, T., Thierry, V., Thomalla, S., Toole, J., Troisi, A., Trull, T. W.,
Turton, J., Velez-Belchi, P. J., Walczowski, W., Wang, H., Wanninkhof, R.,
Waterhouse, A. F., Waterman, S., Watson, A., Wilson, C., Wong, A. P. S., Xu,
J., and Yasuda, I.: On the Future of Argo: A Global, Full-Depth,
Multi-Disciplinary Array, Frontiers in Marine Science, 6, 439,
https://doi.org/10.3389/fmars.2019.00439,
2019. a, b
Siegel, D. A., Buesseler, K. O., Doney, S. C., Sailley, S. F., Behrenfeld,
M. J., and Boyd, P. W.: Global assessment of ocean carbon export by
combining satellite observations and food-web models, Global Biogeochem. Cy., 28, 181–196, https://doi.org/10.1002/2013GB004743,
2014. a
Smagorinsky, J.: General circulation experiments with the primitive equations:
I. the basic experiment, Mon. Weather Rev., 91, 99–164, 1963. a
Smolarkiewicz, P. K. and Margolin, L. G.: MPDATA: A Finite-Difference Solver
for Geophysical Flows, J. Comput. Phys., 140, 459–480,
1998. a
Tjiputra, J. F., Polzin, D., and Winguth, A. M. E.: Assimilation of seasonal
chlorophyll and nutrient data into an adjoint three-dimensional ocean carbon
cycle model: Sensitivity analysis and ecosystem parameter optimization,
Global Biogeochem. Cy., 21, 1–13, https://doi.org/10.1029/2006GB002745, 2007. a
Westberry, T., Behrenfeld, M. J., Siegel, D. A., and Boss, E.: Carbon-based
primary productivity modeling with vertically resolved photoacclimation,
Global Biogeochem. Cy., 22, 1–18, https://doi.org/10.1029/2007GB003078, 2008. a
Xiao, Y. and Friedrichs, M. A. M.: Using biogeochemical data assimilation to assess the relative skill of multiple ecosystem models in the Mid-Atlantic Bight: effects of increasing the complexity of the planktonic food web, Biogeosciences, 11, 3015–3030, https://doi.org/10.5194/bg-11-3015-2014, 2014b. a
Xue, Z., He, R., Fennel, K., Cai, W.-J., Lohrenz, S., and Hopkinson, C.: Modeling ocean circulation and biogeochemical variability in the Gulf of Mexico, Biogeosciences, 10, 7219–7234, https://doi.org/10.5194/bg-10-7219-2013, 2013. a, b
Yu, L., Fennel, K., and Laurent, A.: A modeling study of physical controls on
hypoxia generation in the northern Gulf of Mexico, J. Geophys. Res.-Oceans, 120, 5019–5039, https://doi.org/10.1002/2014JC010634, 2015. a, b
Yu, L., Fennel, K., Wang, B., Laurent, A., Thompson, K. R., and Shay, L. K.:
Evaluation of nonidentical versus identical twin approaches for observation
impact assessments: an ensemble-Kalman-filter-based ocean assimilation
application for the Gulf of Mexico, Ocean Sci., 15, 1801–1814,
https://doi.org/10.5194/os-15-1801-2019, 2019. a
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.
We assess trade-offs between different types of biological observations, specifically satellite...
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