Articles | Volume 14, issue 6
https://doi.org/10.5194/bg-14-1349-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/bg-14-1349-2017
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article
| 
20 Mar 2017
Research article |
| 20 Mar 2017
Linking diverse nutrient patterns to different water masses within anticyclonic eddies in the upwelling system off Peru
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Heiner Dietze
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Andreas Oschlies
GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany
Related authors
Tianfei Xue, Ivy Frenger, A. E. Friederike Prowe, Yonss Saranga José, and Andreas Oschlies
Biogeosciences, 19, 455–475, https://doi.org/10.5194/bg-19-455-2022, https://doi.org/10.5194/bg-19-455-2022, 2022
Short summary
Short summary
The Peruvian system supports 10 % of the world's fishing yield. In the Peruvian system, wind and earth’s rotation bring cold, nutrient-rich water to the surface and allow phytoplankton to grow. But observations show that it grows worse at high upwelling. Using a model, we find that high upwelling happens when air mixes the water the most. Then phytoplankton is diluted and grows slowly due to low light and cool upwelled water. This study helps to estimate how it might change in a warming climate.
Jaard Hauschildt, Soeren Thomsen, Vincent Echevin, Andreas Oschlies, Yonss Saranga José, Gerd Krahmann, Laura A. Bristow, and Gaute Lavik
Biogeosciences, 18, 3605–3629, https://doi.org/10.5194/bg-18-3605-2021, https://doi.org/10.5194/bg-18-3605-2021, 2021
Short summary
Short summary
In this paper we quantify the subduction of upwelled nitrate due to physical processes on the order of several kilometers in the coastal upwelling off Peru and its effect on primary production. We also compare the prepresentation of these processes in a high-resolution simulation (~2.5 km) with a more coarsely resolved simulation (~12 km). To do this, we combine high-resolution shipboard observations of physical and biogeochemical parameters with a complex biogeochemical model configuration.
Mariana Hill Cruz, Iris Kriest, Yonss Saranga José, Rainer Kiko, Helena Hauss, and Andreas Oschlies
Biogeosciences, 18, 2891–2916, https://doi.org/10.5194/bg-18-2891-2021, https://doi.org/10.5194/bg-18-2891-2021, 2021
Short summary
Short summary
In this study we use a regional biogeochemical model of the eastern tropical South Pacific Ocean to implicitly simulate the effect that fluctuations in populations of small pelagic fish, such as anchovy and sardine, may have on the biogeochemistry of the northern Humboldt Current System. To do so, we vary the zooplankton mortality in the model, under the assumption that these fishes eat zooplankton. We also evaluate the model for the first time against mesozooplankton observations.
Yonss Saranga José, Lothar Stramma, Sunke Schmidtko, and Andreas Oschlies
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-155, https://doi.org/10.5194/bg-2019-155, 2019
Revised manuscript accepted for BG
Short summary
Short summary
In situ observations along the Peruvian and Chilean coasts have exhibited variability in the water column oxygen concentration. This variability, which is attributed to the El Niño Southern Oscillation (ENSO), might have implication on the vertical extension of the Eastern Tropical South Pacific (ETSP) oxygen minimum zone. Here using a coupled physical-biogeochemical model, we provide new insights into how ENSO variability affects the vertical extension of the oxygen-poor waters of the ETSP.
Haichao Guo, Wolfgang Koeve, Andreas Oschlies, Yan-Chun He, Tronje Peer Kemena, Lennart Gerke, and Iris Kriest
Ocean Sci., 21, 1167–1182, https://doi.org/10.5194/os-21-1167-2025, https://doi.org/10.5194/os-21-1167-2025, 2025
Short summary
Short summary
We evaluated the effectiveness of the inverse Gaussian transit time distribution (IG-TTD) with respect to estimating the mean state and temporal changes of seawater age, defined as the duration since water last had contact with the atmosphere, within the tropical thermocline. Results suggest that the IG-TTD underestimates seawater age. Moreover, the IG-TTD constrained by a single tracer gives spurious trends in water age. Incorporating an additional tracer improves IG-TTD's accuracy for estimating temporal change of seawater age.
Heiner Dietze and Ulrike Löptien
Biogeosciences, 22, 1215–1236, https://doi.org/10.5194/bg-22-1215-2025, https://doi.org/10.5194/bg-22-1215-2025, 2025
Short summary
Short summary
We introduce argon saturation as a prognostic variable in a suite of coupled general ocean circulation biogeochemical models off Mauritania. Our results indicate that the effect of increasing the spatial horizontal model resolutions from 12 km to 1.5 km leads to changes comparable to other infamous spurious effects of state-of-the-art numerical advection numerics.
Miriam Tivig, David P. Keller, and Andreas Oschlies
Biogeosciences, 21, 4469–4493, https://doi.org/10.5194/bg-21-4469-2024, https://doi.org/10.5194/bg-21-4469-2024, 2024
Short summary
Short summary
Marine biological production is highly dependent on the availability of nitrogen and phosphorus. Rivers are the main source of phosphorus to the oceans but poorly represented in global model oceans. We include dissolved nitrogen and phosphorus from river export in a global model ocean and find that the addition of riverine phosphorus affects marine biology on millennial timescales more than riverine nitrogen alone. Globally, riverine phosphorus input increases primary production rates.
Na Li, Christopher J. Somes, Angela Landolfi, Chia-Te Chien, Markus Pahlow, and Andreas Oschlies
Biogeosciences, 21, 4361–4380, https://doi.org/10.5194/bg-21-4361-2024, https://doi.org/10.5194/bg-21-4361-2024, 2024
Short summary
Short summary
N is a crucial nutrient that limits phytoplankton growth in large ocean areas. The amount of oceanic N is governed by the balance of N2 fixation and denitrification. Here we incorporate benthic denitrification into an Earth system model with variable particulate stoichiometry. Our model compares better to the observed surface nutrient distributions, marine N2 fixation, and primary production. Benthic denitrification plays an important role in marine N and C cycling and hence the global climate.
Timothée Bourgeois, Olivier Torres, Friederike Fröb, Aurich Jeltsch-Thömmes, Giang T. Tran, Jörg Schwinger, Thomas L. Frölicher, Jean Negrel, David Keller, Andreas Oschlies, Laurent Bopp, and Fortunat Joos
EGUsphere, https://doi.org/10.5194/egusphere-2024-2768, https://doi.org/10.5194/egusphere-2024-2768, 2024
Short summary
Short summary
Anthropogenic greenhouse gas emissions significantly impact ocean ecosystems through climate change and acidification, leading to either progressive or abrupt changes. This study maps the crossing of physical and ecological limits for various ocean impact metrics under three emission scenarios. Using Earth system models, we identify when these limits are exceeded, highlighting the urgent need for ambitious climate action to safeguard the world's oceans and ecosystems.
Tianfei Xue, Jens Terhaar, A. E. Friederike Prowe, Thomas L. Frölicher, Andreas Oschlies, and Ivy Frenger
Biogeosciences, 21, 2473–2491, https://doi.org/10.5194/bg-21-2473-2024, https://doi.org/10.5194/bg-21-2473-2024, 2024
Short summary
Short summary
Phytoplankton play a crucial role in marine ecosystems. However, climate change's impact on phytoplankton biomass remains uncertain, particularly in the Southern Ocean. In this region, phytoplankton biomass within the water column is likely to remain stable in response to climate change, as supported by models. This stability arises from a shallower mixed layer, favoring phytoplankton growth but also increasing zooplankton grazing due to phytoplankton concentration near the surface.
Katja Fennel, Matthew C. Long, Christopher Algar, Brendan Carter, David Keller, Arnaud Laurent, Jann Paul Mattern, Ruth Musgrave, Andreas Oschlies, Josiane Ostiguy, Jaime B. Palter, and Daniel B. Whitt
State Planet, 2-oae2023, 9, https://doi.org/10.5194/sp-2-oae2023-9-2023, https://doi.org/10.5194/sp-2-oae2023-9-2023, 2023
Short summary
Short summary
This paper describes biogeochemical models and modelling techniques for applications related to ocean alkalinity enhancement (OAE) research. Many of the most pressing OAE-related research questions cannot be addressed by observation alone but will require a combination of skilful models and observations. We present illustrative examples with references to further information; describe limitations, caveats, and future research needs; and provide practical recommendations.
Andreas Oschlies, Lennart T. Bach, Rosalind E. M. Rickaby, Terre Satterfield, Romany Webb, and Jean-Pierre Gattuso
State Planet, 2-oae2023, 1, https://doi.org/10.5194/sp-2-oae2023-1-2023, https://doi.org/10.5194/sp-2-oae2023-1-2023, 2023
Short summary
Short summary
Reaching promised climate targets will require the deployment of carbon dioxide removal (CDR). Marine CDR options receive more and more interest. Based on idealized theoretical studies, ocean alkalinity enhancement (OAE) appears as a promising marine CDR method. We provide an overview on the current situation of developing OAE as a marine CDR method and describe the history that has led to the creation of the OAE research best practice guide.
Iris Kriest, Julia Getzlaff, Angela Landolfi, Volkmar Sauerland, Markus Schartau, and Andreas Oschlies
Biogeosciences, 20, 2645–2669, https://doi.org/10.5194/bg-20-2645-2023, https://doi.org/10.5194/bg-20-2645-2023, 2023
Short summary
Short summary
Global biogeochemical ocean models are often subjectively assessed and tuned against observations. We applied different strategies to calibrate a global model against observations. Although the calibrated models show similar tracer distributions at the surface, they differ in global biogeochemical fluxes, especially in global particle flux. Simulated global volume of oxygen minimum zones varies strongly with calibration strategy and over time, rendering its temporal extrapolation difficult.
Jiajun Wu, David P. Keller, and Andreas Oschlies
Earth Syst. Dynam., 14, 185–221, https://doi.org/10.5194/esd-14-185-2023, https://doi.org/10.5194/esd-14-185-2023, 2023
Short summary
Short summary
In this study we investigate an ocean-based carbon dioxide removal method: macroalgae open-ocean mariculture and sinking (MOS), which aims to cultivate seaweed in the open-ocean surface and to sink matured biomass quickly to the deep seafloor. Our results suggest that MOS has considerable potential as an ocean-based CDR method. However, MOS has inherent side effects on marine ecosystems and biogeochemistry, which will require careful evaluation beyond this first idealized modeling study.
Chia-Te Chien, Jonathan V. Durgadoo, Dana Ehlert, Ivy Frenger, David P. Keller, Wolfgang Koeve, Iris Kriest, Angela Landolfi, Lavinia Patara, Sebastian Wahl, and Andreas Oschlies
Geosci. Model Dev., 15, 5987–6024, https://doi.org/10.5194/gmd-15-5987-2022, https://doi.org/10.5194/gmd-15-5987-2022, 2022
Short summary
Short summary
We present the implementation and evaluation of a marine biogeochemical model, Model of Oceanic Pelagic Stoichiometry (MOPS) in the Flexible Ocean and Climate Infrastructure (FOCI) climate model. FOCI-MOPS enables the simulation of marine biological processes, the marine carbon, nitrogen and oxygen cycles, and air–sea gas exchange of CO2 and O2. As shown by our evaluation, FOCI-MOPS shows an overall adequate performance that makes it an appropriate tool for Earth climate system simulations.
Tianfei Xue, Ivy Frenger, A. E. Friederike Prowe, Yonss Saranga José, and Andreas Oschlies
Biogeosciences, 19, 455–475, https://doi.org/10.5194/bg-19-455-2022, https://doi.org/10.5194/bg-19-455-2022, 2022
Short summary
Short summary
The Peruvian system supports 10 % of the world's fishing yield. In the Peruvian system, wind and earth’s rotation bring cold, nutrient-rich water to the surface and allow phytoplankton to grow. But observations show that it grows worse at high upwelling. Using a model, we find that high upwelling happens when air mixes the water the most. Then phytoplankton is diluted and grows slowly due to low light and cool upwelled water. This study helps to estimate how it might change in a warming climate.
Karin Kvale, David P. Keller, Wolfgang Koeve, Katrin J. Meissner, Christopher J. Somes, Wanxuan Yao, and Andreas Oschlies
Geosci. Model Dev., 14, 7255–7285, https://doi.org/10.5194/gmd-14-7255-2021, https://doi.org/10.5194/gmd-14-7255-2021, 2021
Short summary
Short summary
We present a new model of biological marine silicate cycling for the University of Victoria Earth System Climate Model (UVic ESCM). This new model adds diatoms, which are a key aspect of the biological carbon pump, to an existing ecosystem model. Our modifications change how the model responds to warming, with net primary production declining more strongly than in previous versions. Diatoms in particular are simulated to decline with climate warming due to their high nutrient requirements.
Maria-Theresia Verwega, Christopher J. Somes, Markus Schartau, Robyn Elizabeth Tuerena, Anne Lorrain, Andreas Oschlies, and Thomas Slawig
Earth Syst. Sci. Data, 13, 4861–4880, https://doi.org/10.5194/essd-13-4861-2021, https://doi.org/10.5194/essd-13-4861-2021, 2021
Short summary
Short summary
This work describes a ready-to-use collection of particulate organic carbon stable isotope ratio data sets. It covers the 1960s–2010s and all main oceans, providing meta-information and gridded data. The best coverage exists in Atlantic, Indian and Southern Ocean surface waters during the 1990s. It indicates no major difference between methods and shows decreasing values towards high latitudes, with the lowest in the Southern Ocean, and a long-term decline in all regions but the Southern Ocean.
Miriam Tivig, David P. Keller, and Andreas Oschlies
Biogeosciences, 18, 5327–5350, https://doi.org/10.5194/bg-18-5327-2021, https://doi.org/10.5194/bg-18-5327-2021, 2021
Short summary
Short summary
Nitrogen is one of the most important elements for life in the ocean. A major source is the riverine discharge of dissolved nitrogen. While global models often omit rivers as a nutrient source, we included nitrogen from rivers in our Earth system model and found that additional nitrogen affected marine biology not only locally but also in regions far off the coast. Depending on regional conditions, primary production was enhanced or even decreased due to internal feedbacks in the nitrogen cycle.
Henrike Schmidt, Julia Getzlaff, Ulrike Löptien, and Andreas Oschlies
Ocean Sci., 17, 1303–1320, https://doi.org/10.5194/os-17-1303-2021, https://doi.org/10.5194/os-17-1303-2021, 2021
Short summary
Short summary
Oxygen-poor regions in the open ocean restrict marine habitats. Global climate simulations show large uncertainties regarding the prediction of these areas. We analyse the representation of the simulated oxygen minimum zones in the Arabian Sea using 10 climate models. We give an overview of the main deficiencies that cause the model–data misfit in oxygen concentrations. This detailed process analysis shall foster future model improvements regarding the oxygen minimum zone in the Arabian Sea.
Heiner Dietze and Ulrike Löptien
Biogeosciences, 18, 4243–4264, https://doi.org/10.5194/bg-18-4243-2021, https://doi.org/10.5194/bg-18-4243-2021, 2021
Short summary
Short summary
In recent years fish-kill events caused by oxygen deficit have been reported in Eckernförde Bight (Baltic Sea). This study sets out to understand the processes causing respective oxygen deficits by combining high-resolution coupled ocean circulation biogeochemical modeling, monitoring data, and artificial intelligence.
Jaard Hauschildt, Soeren Thomsen, Vincent Echevin, Andreas Oschlies, Yonss Saranga José, Gerd Krahmann, Laura A. Bristow, and Gaute Lavik
Biogeosciences, 18, 3605–3629, https://doi.org/10.5194/bg-18-3605-2021, https://doi.org/10.5194/bg-18-3605-2021, 2021
Short summary
Short summary
In this paper we quantify the subduction of upwelled nitrate due to physical processes on the order of several kilometers in the coastal upwelling off Peru and its effect on primary production. We also compare the prepresentation of these processes in a high-resolution simulation (~2.5 km) with a more coarsely resolved simulation (~12 km). To do this, we combine high-resolution shipboard observations of physical and biogeochemical parameters with a complex biogeochemical model configuration.
Mariana Hill Cruz, Iris Kriest, Yonss Saranga José, Rainer Kiko, Helena Hauss, and Andreas Oschlies
Biogeosciences, 18, 2891–2916, https://doi.org/10.5194/bg-18-2891-2021, https://doi.org/10.5194/bg-18-2891-2021, 2021
Short summary
Short summary
In this study we use a regional biogeochemical model of the eastern tropical South Pacific Ocean to implicitly simulate the effect that fluctuations in populations of small pelagic fish, such as anchovy and sardine, may have on the biogeochemistry of the northern Humboldt Current System. To do so, we vary the zooplankton mortality in the model, under the assumption that these fishes eat zooplankton. We also evaluate the model for the first time against mesozooplankton observations.
Markus Pahlow, Chia-Te Chien, Lionel A. Arteaga, and Andreas Oschlies
Geosci. Model Dev., 13, 4663–4690, https://doi.org/10.5194/gmd-13-4663-2020, https://doi.org/10.5194/gmd-13-4663-2020, 2020
Short summary
Short summary
The stoichiometry of marine biotic processes is important for the regulation of atmospheric CO2 and hence the global climate. We replace a simplistic, fixed-stoichiometry plankton module in an Earth system model with an optimal-regulation model with variable stoichiometry. Our model compares better to the observed carbon transfer from the surface to depth and surface nutrient distributions. This work could aid our ability to describe and project the role of marine ecosystems in the Earth system.
Chia-Te Chien, Markus Pahlow, Markus Schartau, and Andreas Oschlies
Geosci. Model Dev., 13, 4691–4712, https://doi.org/10.5194/gmd-13-4691-2020, https://doi.org/10.5194/gmd-13-4691-2020, 2020
Short summary
Short summary
We demonstrate sensitivities of tracers to parameters of a new optimality-based plankton–ecosystem model (OPEM) in the UVic-ESCM. We find that changes in phytoplankton subsistence nitrogen quota strongly impact the nitrogen inventory, nitrogen fixation, and elemental stoichiometry of ordinary phytoplankton and diazotrophs. We introduce a new likelihood-based metric for model calibration, and it shows the capability of constraining globally averaged oxygen, nitrate, and DIC concentrations.
Nadine Mengis, David P. Keller, Andrew H. MacDougall, Michael Eby, Nesha Wright, Katrin J. Meissner, Andreas Oschlies, Andreas Schmittner, Alexander J. MacIsaac, H. Damon Matthews, and Kirsten Zickfeld
Geosci. Model Dev., 13, 4183–4204, https://doi.org/10.5194/gmd-13-4183-2020, https://doi.org/10.5194/gmd-13-4183-2020, 2020
Short summary
Short summary
In this paper, we evaluate the newest version of the University of Victoria Earth System Climate Model (UVic ESCM 2.10). Combining recent model developments as a joint effort, this version is to be used in the next phase of model intercomparison and climate change studies. The UVic ESCM 2.10 is capable of reproducing changes in historical temperature and carbon fluxes well. Additionally, the model is able to reproduce the three-dimensional distribution of many ocean tracers.
Sabine Mathesius, Julia Getzlaff, Heiner Dietze, Andreas Oschlies, and Markus Schartau
Earth Syst. Sci. Data, 12, 1775–1787, https://doi.org/10.5194/essd-12-1775-2020, https://doi.org/10.5194/essd-12-1775-2020, 2020
Short summary
Short summary
Controlled manipulation of environmental conditions within large enclosures in the ocean, pelagic mesocosms, has become a standard method to explore responses of marine plankton communities to anthropogenic change. Among the challenges of interpreting mesocosm data is the often uncertain role of vertical mixing. This study introduces a mesocosm mixing model that is able to estimate vertical diffusivities and thus provides a tool for future mesocosm data analyses that account for mixing.
Iris Kriest, Paul Kähler, Wolfgang Koeve, Karin Kvale, Volkmar Sauerland, and Andreas Oschlies
Biogeosciences, 17, 3057–3082, https://doi.org/10.5194/bg-17-3057-2020, https://doi.org/10.5194/bg-17-3057-2020, 2020
Short summary
Short summary
Constants of global biogeochemical ocean models are often tuned
by handto match observations of nutrients or oxygen. We investigate the effect of this tuning by optimising six constants of a global biogeochemical model, simulated in five different offline circulations. Optimal values for three constants adjust to distinct features of the circulation applied and can afterwards be swapped among the circulations, without losing too much of the model's fit to observed quantities.
Fabian Reith, Wolfgang Koeve, David P. Keller, Julia Getzlaff, and Andreas Oschlies
Earth Syst. Dynam., 10, 711–727, https://doi.org/10.5194/esd-10-711-2019, https://doi.org/10.5194/esd-10-711-2019, 2019
Short summary
Short summary
This modeling study is the first one to look at the suitability and collateral effects of direct CO2 injection into the deep ocean as a means to bridge the gap between CO2 emissions and climate impacts of an intermediate CO2 emission scenario and a temperature target on a millennium timescale, such as the 1.5 °C climate target of the Paris Agreement.
Tronje P. Kemena, Angela Landolfi, Andreas Oschlies, Klaus Wallmann, and Andrew W. Dale
Earth Syst. Dynam., 10, 539–553, https://doi.org/10.5194/esd-10-539-2019, https://doi.org/10.5194/esd-10-539-2019, 2019
Short summary
Short summary
Oceanic deoxygenation is driven by climate change in several areas of the global ocean. Measurements indicate that ocean volumes with very low oxygen levels expand, with consequences for marine organisms and fishery. We found climate-change-driven phosphorus (P) input in the ocean is hereby an important driver for deoxygenation on longer timescales with effects in the next millennia.
Daniela Niemeyer, Iris Kriest, and Andreas Oschlies
Biogeosciences, 16, 3095–3111, https://doi.org/10.5194/bg-16-3095-2019, https://doi.org/10.5194/bg-16-3095-2019, 2019
Short summary
Short summary
Recent studies suggest spatial variations of the marine particle flux length scale. Using a global biogeochemical ocean model, we investigate whether changes in particle size and size-dependent sinking can explain this variation. We address uncertainties by varying aggregate properties and circulation. Both aspects have an impact on the representation of nutrients, oxygen and oxygen minimum zones. The formation and sinking of large aggregates in productive areas lead to deeper flux penetration.
Ulrike Löptien and Heiner Dietze
Biogeosciences, 16, 1865–1881, https://doi.org/10.5194/bg-16-1865-2019, https://doi.org/10.5194/bg-16-1865-2019, 2019
Short summary
Short summary
Anthropogenic greenhouse gas emissions trigger complex climate feedbacks. Output form Earth system models provides a basis for related political decision-making. One challenge is to arrive at reliable model parameter estimates for the ocean biogeochemistry module. We illustrate pitfalls through which flaws in the ocean module are masked by wrongly tuning the biogeochemistry and discuss ensuing uncertainties in climate projections.
Yonss Saranga José, Lothar Stramma, Sunke Schmidtko, and Andreas Oschlies
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-155, https://doi.org/10.5194/bg-2019-155, 2019
Revised manuscript accepted for BG
Short summary
Short summary
In situ observations along the Peruvian and Chilean coasts have exhibited variability in the water column oxygen concentration. This variability, which is attributed to the El Niño Southern Oscillation (ENSO), might have implication on the vertical extension of the Eastern Tropical South Pacific (ETSP) oxygen minimum zone. Here using a coupled physical-biogeochemical model, we provide new insights into how ENSO variability affects the vertical extension of the oxygen-poor waters of the ETSP.
Olaf Duteil, Andreas Oschlies, and Claus W. Böning
Biogeosciences, 15, 7111–7126, https://doi.org/10.5194/bg-15-7111-2018, https://doi.org/10.5194/bg-15-7111-2018, 2018
Short summary
Short summary
Oxygen-depleted regions of the Pacific Ocean are currently expanding, which is threatening marine habitats. Based on numerical simulations, we show that the decrease in the intensity of the trade winds and the subsequent slowdown of the oceanic currents lead to a reduction in oxygen supply. Our study suggests that the prevailing positive conditions of the Pacific Decadal Oscillation since 1975, a major source of natural variability, may explain a significant part of the current deoxygenation.
Marine Bretagnon, Aurélien Paulmier, Véronique Garçon, Boris Dewitte, Séréna Illig, Nathalie Leblond, Laurent Coppola, Fernando Campos, Federico Velazco, Christos Panagiotopoulos, Andreas Oschlies, J. Martin Hernandez-Ayon, Helmut Maske, Oscar Vergara, Ivonne Montes, Philippe Martinez, Edgardo Carrasco, Jacques Grelet, Olivier Desprez-De-Gesincourt, Christophe Maes, and Lionel Scouarnec
Biogeosciences, 15, 5093–5111, https://doi.org/10.5194/bg-15-5093-2018, https://doi.org/10.5194/bg-15-5093-2018, 2018
Short summary
Short summary
In oxygen minimum zone, the fate of the organic matter is a key question as the low oxygen condition would preserve the OM and thus enhance the biological carbon pump while the high microbial activity would foster the remineralisation and the greenhouse gases emission. To investigate this paradigm, sediment traps were deployed off Peru. We pointed out the influence of the oxygenation as well as the organic matter quantity and quality on the carbon transfer efficiency in the oxygen minimum zone.
Volkmar Sauerland, Ulrike Löptien, Claudine Leonhard, Andreas Oschlies, and Anand Srivastav
Geosci. Model Dev., 11, 1181–1198, https://doi.org/10.5194/gmd-11-1181-2018, https://doi.org/10.5194/gmd-11-1181-2018, 2018
Short summary
Short summary
We present a concept to prove that a parametric model is well calibrated, i.e., that changes of its free parameters cannot lead to a much better model–data misfit anymore. The intention is motivated by the fact that calibrating global biogeochemical ocean models is important for assessment and inter-model comparison but computationally expensive.
Nadine Mengis, David P. Keller, and Andreas Oschlies
Earth Syst. Dynam., 9, 15–31, https://doi.org/10.5194/esd-9-15-2018, https://doi.org/10.5194/esd-9-15-2018, 2018
Short summary
Short summary
The Systematic Correlation Matrix Evaluation (SCoMaE) method applies statistical information to systematically select, transparent, nonredundant indicators for a comprehensive assessment of the Earth system state. We show that due to changing climate forcing, such as anthropogenic climate change, the ad hoc assessment indicators might need to be reevaluated. Within an iterative process, this method would allow us to select scientifically consistent and societally relevant assessment indicators.
Karin F. Kvale, Samar Khatiwala, Heiner Dietze, Iris Kriest, and Andreas Oschlies
Geosci. Model Dev., 10, 2425–2445, https://doi.org/10.5194/gmd-10-2425-2017, https://doi.org/10.5194/gmd-10-2425-2017, 2017
Short summary
Short summary
Computer models of ocean biology and chemistry are becoming increasingly complex, and thus more expensive, to run. One solution is to approximate the behaviour of the ocean physics and store that information outside of the model. That
offlineinformation can then be used to calculate a steady-state solution from the model's biology and chemistry, without waiting for a traditional
onlineintegration to complete. We show this offline method reproduces online results and is 100 times faster.
James C. Orr, Raymond G. Najjar, Olivier Aumont, Laurent Bopp, John L. Bullister, Gokhan Danabasoglu, Scott C. Doney, John P. Dunne, Jean-Claude Dutay, Heather Graven, Stephen M. Griffies, Jasmin G. John, Fortunat Joos, Ingeborg Levin, Keith Lindsay, Richard J. Matear, Galen A. McKinley, Anne Mouchet, Andreas Oschlies, Anastasia Romanou, Reiner Schlitzer, Alessandro Tagliabue, Toste Tanhua, and Andrew Yool
Geosci. Model Dev., 10, 2169–2199, https://doi.org/10.5194/gmd-10-2169-2017, https://doi.org/10.5194/gmd-10-2169-2017, 2017
Short summary
Short summary
The Ocean Model Intercomparison Project (OMIP) is a model comparison effort under Phase 6 of the Coupled Model Intercomparison Project (CMIP6). Its physical component is described elsewhere in this special issue. Here we describe its ocean biogeochemical component (OMIP-BGC), detailing simulation protocols and analysis diagnostics. Simulations focus on ocean carbon, other biogeochemical tracers, air-sea exchange of CO2 and related gases, and chemical tracers used to evaluate modeled circulation.
Daniela Niemeyer, Tronje P. Kemena, Katrin J. Meissner, and Andreas Oschlies
Earth Syst. Dynam., 8, 357–367, https://doi.org/10.5194/esd-8-357-2017, https://doi.org/10.5194/esd-8-357-2017, 2017
Markus Schartau, Philip Wallhead, John Hemmings, Ulrike Löptien, Iris Kriest, Shubham Krishna, Ben A. Ward, Thomas Slawig, and Andreas Oschlies
Biogeosciences, 14, 1647–1701, https://doi.org/10.5194/bg-14-1647-2017, https://doi.org/10.5194/bg-14-1647-2017, 2017
Short summary
Short summary
Plankton models have become an integral part in marine ecosystem and biogeochemical research. These models differ in complexity and in their number of parameters. How values are assigned to parameters is essential. An overview of major methodologies of parameter estimation is provided. Aspects of parameter identification in the literature are diverse. Individual findings could be better synthesized if notation and expertise of the different scientific communities would be reasonably merged.
Heiner Dietze, Julia Getzlaff, and Ulrike Löptien
Biogeosciences, 14, 1561–1576, https://doi.org/10.5194/bg-14-1561-2017, https://doi.org/10.5194/bg-14-1561-2017, 2017
Short summary
Short summary
The Southern Ocean is a sink for anthropogenic carbon. Projections of how this sink will evolve in an ever-warming climate are based on coupled ocean-circulation–biogeochemical models. This study compares uncertainties of simulated oceanic carbon uptake associated to physical (eddy) parameterizations with those associated wtih (unconstrained) supply of bioavailable iron supply to the surface ocean.
Iris Kriest, Volkmar Sauerland, Samar Khatiwala, Anand Srivastav, and Andreas Oschlies
Geosci. Model Dev., 10, 127–154, https://doi.org/10.5194/gmd-10-127-2017, https://doi.org/10.5194/gmd-10-127-2017, 2017
Short summary
Short summary
Global biogeochemical ocean models are subject to a high level of parametric uncertainty. This may be of consequence for their skill with respect to accurately describing features of the present ocean and their sensitivity to possible environmental changes. We present the first results from a framework that combines an offline biogeochemical tracer transport model with an estimation of distribution algorithm, calibrating six biogeochemical model parameters against observed oxygen and nutrients.
Fabian Reith, David P. Keller, and Andreas Oschlies
Earth Syst. Dynam., 7, 797–812, https://doi.org/10.5194/esd-7-797-2016, https://doi.org/10.5194/esd-7-797-2016, 2016
Bei Su, Markus Pahlow, and Andreas Oschlies
Biogeosciences, 13, 4985–5001, https://doi.org/10.5194/bg-13-4985-2016, https://doi.org/10.5194/bg-13-4985-2016, 2016
Short summary
Short summary
Previously identified positive feedbacks within the nitrogen cycle in the eastern tropical South Pacific (ETSP) have challenged our understanding of the observed dynamics and stability of the nitrogen inventory. We present a box model analysis of the biological and biogeochemical relations in the ETSP among nitrogen deposition, benthic denitrification and phosphate regeneration. Our results suggest dominant stabilizing feedbacks tending to keep a balanced nitrogen inventory in the ETSP.
Heiner Dietze and Ulrike Löptien
Ocean Sci., 12, 977–986, https://doi.org/10.5194/os-12-977-2016, https://doi.org/10.5194/os-12-977-2016, 2016
Short summary
Short summary
Winds blowing over the ocean drive ocean currents. The oceanic response to winds is, in turn, influenced by ocean currents. Theoretical considerations suggest that the latter effect is especially pronounced in the Baltic Sea. The study presented here puts theses theoretical considerations in a high-resolution ocean circulation model of the Baltic Sea to the test.
I. Kriest and A. Oschlies
Geosci. Model Dev., 8, 2929–2957, https://doi.org/10.5194/gmd-8-2929-2015, https://doi.org/10.5194/gmd-8-2929-2015, 2015
Short summary
Short summary
We use a global model of oceanic P, N, and O2 cycles to investigate consequences of uncertainties in description of organic matter sinking, remineralization, denitrification, and N2-Fixation. After all biogeochemical and physical processes have been spun-up into a dynamically consistent steady-state, particle sinking and oxidant affinities of aerobic and anaerobic remineralization determine the extent of oxygen minimum zones, global nitrogen fluxes, and the oceanic nitrogen inventory.
U. Löptien and H. Dietze
Ocean Sci., 11, 573–590, https://doi.org/10.5194/os-11-573-2015, https://doi.org/10.5194/os-11-573-2015, 2015
Short summary
Short summary
Marine biogeochemical ocean models are embedded into earth system models - which are, to an increasing degree, applied to project the fate of our warming world. These biogeochemical models generally depend on poorly constrained model parameters. In this study we investigate the the demands on observations for an objective estimation of such parameters. A major result is that even modest noise (10%) inherent to observations can hinder the assignment of reasonable parameters.
W. Koeve, H. Wagner, P. Kähler, and A. Oschlies
Geosci. Model Dev., 8, 2079–2094, https://doi.org/10.5194/gmd-8-2079-2015, https://doi.org/10.5194/gmd-8-2079-2015, 2015
Short summary
Short summary
The natural abundance of 14C in CO2 dissolved in seawater is often used to evaluate circulation and age in the ocean and in ocean models. We study limitations of using natural 14C to determine the time elapsed since water had contact with the atmosphere. We find that, globally, bulk 14C age is dominated by two equally important components, (1) the time component of circulation and (2) the “preformed 14C-age”. Considering preformed 14C-age is critical for an assessment of circulation in models.
L. Nickelsen, D. P. Keller, and A. Oschlies
Geosci. Model Dev., 8, 1357–1381, https://doi.org/10.5194/gmd-8-1357-2015, https://doi.org/10.5194/gmd-8-1357-2015, 2015
Short summary
Short summary
In this paper we find that including the marine cycle of the phytoplankton nutrient iron in a global climate model improves the agreement between observed and simulated nutrient concentrations in the ocean and that a better description of the source of iron from the sediment to the ocean is more important than that of iron-containing dust deposition. Finally, we find that the response of the iron cycle to climate warming affects the phytoplankton growth and nutrient cycles.
B. Su, M. Pahlow, H. Wagner, and A. Oschlies
Biogeosciences, 12, 1113–1130, https://doi.org/10.5194/bg-12-1113-2015, https://doi.org/10.5194/bg-12-1113-2015, 2015
Short summary
Short summary
A box model of the eastern tropical South Pacific oxygen minimum zone suggests that anaerobic water-column remineralization rates have to be slower than aerobic remineralization in order to explain the relatively high values of observed nitrate concentrations. Lateral oxygen supply sufficient to oxidize about one-fifth of the export production is required to prevent an anoxic deep ocean. Under these circumstances, the region can be a net source of fixed nitrogen to the surrounding ocean.
U. Löptien and H. Dietze
Earth Syst. Sci. Data, 6, 367–374, https://doi.org/10.5194/essd-6-367-2014, https://doi.org/10.5194/essd-6-367-2014, 2014
W. Koeve, O. Duteil, A. Oschlies, P. Kähler, and J. Segschneider
Geosci. Model Dev., 7, 2393–2408, https://doi.org/10.5194/gmd-7-2393-2014, https://doi.org/10.5194/gmd-7-2393-2014, 2014
H. Dietze, U. Löptien, and K. Getzlaff
Geosci. Model Dev., 7, 1713–1731, https://doi.org/10.5194/gmd-7-1713-2014, https://doi.org/10.5194/gmd-7-1713-2014, 2014
A. E. F. Prowe, M. Pahlow, S. Dutkiewicz, and A. Oschlies
Biogeosciences, 11, 3397–3407, https://doi.org/10.5194/bg-11-3397-2014, https://doi.org/10.5194/bg-11-3397-2014, 2014
I. Kriest and A. Oschlies
Biogeosciences, 10, 8401–8422, https://doi.org/10.5194/bg-10-8401-2013, https://doi.org/10.5194/bg-10-8401-2013, 2013
O. Duteil, W. Koeve, A. Oschlies, D. Bianchi, E. Galbraith, I. Kriest, and R. Matear
Biogeosciences, 10, 7723–7738, https://doi.org/10.5194/bg-10-7723-2013, https://doi.org/10.5194/bg-10-7723-2013, 2013
C. J. Somes, A. Oschlies, and A. Schmittner
Biogeosciences, 10, 5889–5910, https://doi.org/10.5194/bg-10-5889-2013, https://doi.org/10.5194/bg-10-5889-2013, 2013
V. Cocco, F. Joos, M. Steinacher, T. L. Frölicher, L. Bopp, J. Dunne, M. Gehlen, C. Heinze, J. Orr, A. Oschlies, B. Schneider, J. Segschneider, and J. Tjiputra
Biogeosciences, 10, 1849–1868, https://doi.org/10.5194/bg-10-1849-2013, https://doi.org/10.5194/bg-10-1849-2013, 2013
A. Landolfi, H. Dietze, W. Koeve, and A. Oschlies
Biogeosciences, 10, 1351–1363, https://doi.org/10.5194/bg-10-1351-2013, https://doi.org/10.5194/bg-10-1351-2013, 2013
M. El Jarbi, J. Rückelt, T. Slawig, and A. Oschlies
Biogeosciences, 10, 1169–1182, https://doi.org/10.5194/bg-10-1169-2013, https://doi.org/10.5194/bg-10-1169-2013, 2013
L. M. Zamora, A. Oschlies, H. W. Bange, K. B. Huebert, J. D. Craig, A. Kock, and C. R. Löscher
Biogeosciences, 9, 5007–5022, https://doi.org/10.5194/bg-9-5007-2012, https://doi.org/10.5194/bg-9-5007-2012, 2012
Related subject area
Biogeophysics: Physical - Biological Coupling
Phytoplankton blooming mechanisms over the East China Sea during post-El Niño summers
Impact of stratiform liquid water clouds on vegetation albedo quantified by coupling an atmosphere and a vegetation radiative transfer model
Technical note: Investigating saline water uptake by roots using spectral induced polarization
Can atmospheric chemistry deposition schemes reliably simulate stomatal ozone flux across global land covers and climates?
Source-to-sink pathways of dissolved organic carbon in the river–estuary–ocean continuum: a modeling investigation
Estimating the variability of deep ocean particle flux collected by sediment traps using satellite data and machine learning
Impact of livestock activity on near-surface ground temperatures in central Mongolian grasslands
Evolution of biogeochemical Properties Inside Poleward Undercurrent Eddies in the Southeast Pacific Ocean
Impact of canopy environmental variables on the diurnal dynamics of water and carbon dioxide exchange at leaf and canopy level
Unique ocean circulation pathways reshape the Indian Ocean oxygen minimum zone with warming
Contribution of the open ocean to the nutrient and phytoplankton inventory in a semi-enclosed coastal sea
The contrasted phytoplankton dynamics across a frontal system in the southwestern Mediterranean Sea
Sub-frontal niches of plankton communities driven by transport and trophic interactions at ocean fronts
Differential feeding habits of the shallow-water hydrothermal vent crab Xenograpsus testudinatus correlate with their resident vent types at a scale of meters
Satellite data reveal earlier and stronger phytoplankton blooms over fronts in the Gulf Stream region
Assimilation of multiple datasets results in large differences in regional- to global-scale NEE and GPP budgets simulated by a terrestrial biosphere model
Spatiotemporal lagging of predictors improves machine learning estimates of atmosphere–forest CO2 exchange
Phytoplankton reaction to an intense storm in the north-western Mediterranean Sea
Lagrangian and Eulerian time and length scales of mesoscale ocean chlorophyll from Bio-Argo floats and satellites
Reply to Lars Olof Björn's comment on “Fundamental molecules of life are pigments which arose and co-evolved as a response to the thermodynamic imperative of dissipating the prevailing solar spectrum” by Michaelian and Simeonov (2015)
Modelling submerged biofouled microplastics and their vertical trajectories
A Bayesian sequential updating approach to predict phenology of silage maize
Using an oceanographic model to investigate the mystery of the missing puerulus
Climate pathways behind phytoplankton-induced atmospheric warming
Impact of moderately energetic fine-scale dynamics on the phytoplankton community structure in the western Mediterranean Sea
Seasonal ecosystem vulnerability to climatic anomalies in the Mediterranean
Grazing behavior and winter phytoplankton accumulation
Episodic subduction patches in the western North Pacific identified from BGC-Argo float data
Do Loop Current eddies stimulate productivity in the Gulf of Mexico?
Quasi-tropical cyclone caused anomalous autumn coccolithophore bloom in the Black Sea
Divergent climate feedbacks on winter wheat growing and dormancy periods as affected by sowing date in the North China Plain
Microclimatic comparison of lichen heaths and shrubs: shrubification generates atmospheric heating but subsurface cooling during the growing season
Fire and vegetation dynamics in northwest Siberia during the last 60 years based on high-resolution remote sensing
Evidence of eddy-related deep-ocean current variability in the northeast tropical Pacific Ocean induced by remote gap winds
Root uptake under mismatched distributions of water and nutrients in the root zone
Interactive impacts of meteorological and hydrological conditions on the physical and biogeochemical structure of a coastal system
Protists and collembolans alter microbial community composition, C dynamics and soil aggregation in simplified consumer–prey systems
Abundance and viability of particle-attached and free-floating bacteria in dusty and nondusty air
Linking tundra vegetation, snow, soil temperature, and permafrost
Drivers of the spatial phytoplankton gradient in estuarine–coastal systems: generic implications of a case study in a Dutch tidal bay
Biological and biogeochemical methods for estimating bioirrigation: a case study in the Oosterschelde estuary
Dissolved inorganic nitrogen and particulate organic nitrogen budget in the Yucatán shelf: driving mechanisms through a physical–biogeochemical coupled model
Basal thermal regime affects the biogeochemistry of subglacial systems
Influence of oceanic conditions in the energy transfer efficiency estimation of a micronekton model
Modulation of the North Atlantic deoxygenation by the slowdown of the nutrient stream
Stand age and species composition effects on surface albedo in a mixedwood boreal forest
Assessing the peatland hummock–hollow classification framework using high-resolution elevation models: implications for appropriate complexity ecosystem modeling
Tidal and seasonal forcing of dissolved nutrient fluxes in reef communities
Ideas and perspectives: Development of nascent autotrophic carbon fixation systems in various redox conditions of the fluid degassing on early Earth
Vertical distribution of chlorophyll in dynamically distinct regions of the southern Bay of Bengal
Dong-Geon Lee, Ji-Hoon Oh, Jonghun Kam, and Jong-Seong Kug
Biogeosciences, 22, 3165–3180, https://doi.org/10.5194/bg-22-3165-2025, https://doi.org/10.5194/bg-22-3165-2025, 2025
Short summary
Short summary
This study investigates the mechanisms driving anomalous phytoplankton blooms in the East China Sea (ECS) during El Niño decaying summers. The findings highlight three key mechanisms: increased river runoff, nutrient transport through the Taiwan Strait, and wind-driven upwelling, all linked to the western North Pacific anticyclone (WNPAC).
Kevin Wolf, Evelyn Jäkel, André Ehrlich, Michael Schäfer, Hannes Feilhauer, Andreas Huth, Alexandra Weigelt, and Manfred Wendisch
Biogeosciences, 22, 2909–2933, https://doi.org/10.5194/bg-22-2909-2025, https://doi.org/10.5194/bg-22-2909-2025, 2025
Short summary
Short summary
This paper reports an investigation of the influence of clouds on vegetation albedo using a coupled atmosphere–vegetation radiative transfer model. Both models are iteratively linked to simulate cloud–vegetation–radiation interactions over canopies more realistically. Solar, spectral, and broadband irradiances have been simulated under varying cloud conditions. The simulated irradiances were used to investigate the spectral and broadband effect of clouds on vegetation albedo.
Solomon Ehosioke, Sarah Garré, Johan Alexander Huisman, Egon Zimmermann, Mathieu Javaux, and Frédéric Nguyen
Biogeosciences, 22, 2853–2869, https://doi.org/10.5194/bg-22-2853-2025, https://doi.org/10.5194/bg-22-2853-2025, 2025
Short summary
Short summary
Understanding the electromagnetic properties of plant roots is useful to quantify plant properties and monitor plant physiological responses to changing environmental factors. We investigated the electrical properties of the primary roots of Brachypodium and maize plants during the uptake of fresh and saline water using spectral induced polarization. Our results indicate that salinity tolerance varies with the species and that Maize is more tolerant to salinity than Brachypodium.
Tamara Emmerichs, Abdulla Al Mamun, Lisa Emberson, Huiting Mao, Leiming Zhang, Limei Ran, Clara Betancourt, Anthony Wong, Gerbrand Koren, Giacomo Gerosa, Min Huang, and Pierluigi Guaita
EGUsphere, https://doi.org/10.5194/egusphere-2025-429, https://doi.org/10.5194/egusphere-2025-429, 2025
Short summary
Short summary
The risk of ozone pollution to plants is estimated based on the flux through the plant pores which still has uncertainties. In this study, we estimate this quantity with 9 models at different land types worldwide. The input data stems from a database. The models estimated mostly reasonable summertime ozone deposition. The different results of the models varied by land cover which were mostly related to the moisture deficit. This is an important step for assessing the ozone impact on vegetation.
Jialing Yao, Zhi Chen, Jianzhong Ge, and Wenyan Zhang
Biogeosciences, 21, 5435–5455, https://doi.org/10.5194/bg-21-5435-2024, https://doi.org/10.5194/bg-21-5435-2024, 2024
Short summary
Short summary
The transformation of dissolved organic carbon (DOC) in estuaries is vital for coastal carbon cycling. We studied source-to-sink pathways of DOC in the Changjiang Estuary using a physics–biogeochemistry model. Results showed a transition of DOC from a sink to a source in the plume area during summer, with a transition from terrestrial-dominant to marine-dominant DOC. Terrigenous and marine DOC exports account for about 31 % and 69 %, respectively.
Théo Picard, Chelsey A. Baker, Jonathan Gula, Ronan Fablet, Laurent Mémery, and Richard Lampitt
EGUsphere, https://doi.org/10.5194/egusphere-2024-3292, https://doi.org/10.5194/egusphere-2024-3292, 2024
Short summary
Short summary
Ocean sediment traps measure the sequestrated sinking organic carbon. While sinking, the particles are affected by local currents, which presents a challenge in linking the deep flux with the surface. We present a machine learning tool that predicts the source location of the sinking particles based on satellite data. The predictions demonstrate a stronger correlation between surface and deep carbon fluxes, allowing a more comprehensive understanding of the deep carbon sequestration drivers.
Robin Benjamin Zweigel, Avirmed Dashtseren, Khurelbaatar Temuujin, Anarmaa Sharkhuu, Clare Webster, Hanna Lee, and Sebastian Westermann
Biogeosciences, 21, 5059–5077, https://doi.org/10.5194/bg-21-5059-2024, https://doi.org/10.5194/bg-21-5059-2024, 2024
Short summary
Short summary
Intense grazing at grassland sites removes vegetation, reduces the snow cover, and inhibits litter layers from forming. Grazed sites generally have a larger annual ground surface temperature amplitude than ungrazed sites, but the net effect depends on effects in the transitional seasons. Our results also suggest that seasonal use of pastures can reduce ground temperatures, which can be a strategy to protect currently degrading grassland permafrost.
Lenna Oriana Ortiz-Castillo, Oscar Pizarro, Marcela Cornejo-D'Ottone, and Boris Dewitte
EGUsphere, https://doi.org/10.5194/egusphere-2024-1290, https://doi.org/10.5194/egusphere-2024-1290, 2024
Short summary
Short summary
Poleward undercurrent eddies (Puddies) transport a source water mass with low oxygen hundreds of kilometers away from the coast. A simulation based on a physical-biogeochemical model was used to characterize the biogeochemical average conditions inside the Puddies during their lifetime while modifying the conditions in the open sea. Our findings show that the biological activity extends the low oxygen core conditions counteracted by advection processes that tend to ventilate the core.
Raquel González-Armas, Jordi Vilà-Guerau de Arellano, Mary Rose Mangan, Oscar Hartogensis, and Hugo de Boer
Biogeosciences, 21, 2425–2445, https://doi.org/10.5194/bg-21-2425-2024, https://doi.org/10.5194/bg-21-2425-2024, 2024
Short summary
Short summary
This paper investigates the water and CO2 exchange for an alfalfa field with observations and a model with spatial scales ranging from the stomata to the atmospheric boundary layer. To relate the environmental factors to the leaf gas exchange, we developed three equations that quantify how many of the temporal changes of the leaf gas exchange occur due to changes in the environmental variables. The novelty of the research resides in the capacity to dissect the dynamics of the leaf gas exchange.
Sam Ditkovsky, Laure Resplandy, and Julius Busecke
Biogeosciences, 20, 4711–4736, https://doi.org/10.5194/bg-20-4711-2023, https://doi.org/10.5194/bg-20-4711-2023, 2023
Short summary
Short summary
The global ocean is losing oxygen due to warming. The Indian Ocean, however, is gaining oxygen in large parts of the basin, and its naturally occurring oxygen minimum zone is not expanding. This rather unexpected response is explained by the unique ocean circulation of the Indian Ocean, which is bounded by a continent to the north but connected to the Pacific Ocean by the Indonesian Throughflow.
Qian Leng, Xinyu Guo, Junying Zhu, and Akihiko Morimoto
Biogeosciences, 20, 4323–4338, https://doi.org/10.5194/bg-20-4323-2023, https://doi.org/10.5194/bg-20-4323-2023, 2023
Short summary
Short summary
Using a numerical model, we revealed that a large proportion of nutrients in a semi-enclosed sea (Seto Inland Sea, Japan) comes from the Pacific Ocean and supports about half of the phytoplankton growth in the sea. Such results imply that the human-made management of nutrient load from land needs to consider the presence of oceanic nutrients, which act as a background concentration and are not controlled by human activities.
Roxane Tzortzis, Andrea M. Doglioli, Monique Messié, Stéphanie Barrillon, Anne A. Petrenko, Lloyd Izard, Yuan Zhao, Francesco d'Ovidio, Franck Dumas, and Gérald Gregori
Biogeosciences, 20, 3491–3508, https://doi.org/10.5194/bg-20-3491-2023, https://doi.org/10.5194/bg-20-3491-2023, 2023
Short summary
Short summary
We studied a finescale frontal structure in order to highlight its influence on the dynamics and distribution of phytoplankton communities. We computed the growth rates of several phytoplankton groups identified by flow cytometry in two water masses separated by the front. We found contrasted phytoplankton dynamics on the two sides of the front, consistent with the distribution of their abundances. Our study gives new insights into the physical and biological coupling on a finescale front.
Inès Mangolte, Marina Lévy, Clément Haëck, and Mark D. Ohman
Biogeosciences, 20, 3273–3299, https://doi.org/10.5194/bg-20-3273-2023, https://doi.org/10.5194/bg-20-3273-2023, 2023
Short summary
Short summary
Ocean fronts are ecological hotspots, associated with higher diversity and biomass for many marine organisms, from bacteria to whales. Using in situ data from the California Current Ecosystem, we show that far from being limited to the production of diatom blooms, fronts are the scene of complex biophysical couplings between biotic interactions (growth, competition, and predation) and transport by currents that generate planktonic communities with an original taxonomic and spatial structure.
Jing-Ying Wu, Siou-Yan Lin, Jung-Fu Huang, Chen-Tung Arthur Chen, Jia-Jang Hung, Shao-Hung Peng, and Li-Lian Liu
Biogeosciences, 20, 2693–2706, https://doi.org/10.5194/bg-20-2693-2023, https://doi.org/10.5194/bg-20-2693-2023, 2023
Short summary
Short summary
The shallow-water hydrothermal vents off the Kueishan Island, Taiwan, have the most extreme records of pH values (1.52), temperatures (116 °C), and H2S concentrations (172.4 mmol mol−1) in the world. White and yellow vents differ in the color and physical and chemical characteristics of emitted plumes. We found that the feeding habits of the endemic vent crabs (Xenograpsus testudinatus) are adapted to their resident vent types at a distance of 100 m, and the trans-vent movement is uncommon.
Clément Haëck, Marina Lévy, Inès Mangolte, and Laurent Bopp
Biogeosciences, 20, 1741–1758, https://doi.org/10.5194/bg-20-1741-2023, https://doi.org/10.5194/bg-20-1741-2023, 2023
Short summary
Short summary
Phytoplankton vary in abundance in the ocean over large regions and with the seasons but also because of small-scale heterogeneities in surface temperature, called fronts. Here, using satellite imagery, we found that fronts enhance phytoplankton much more where it is already growing well, but despite large local increases the enhancement for the region is modest (5 %). We also found that blooms start 1 to 2 weeks earlier over fronts. These effects may have implications for ecosystems.
Cédric Bacour, Natasha MacBean, Frédéric Chevallier, Sébastien Léonard, Ernest N. Koffi, and Philippe Peylin
Biogeosciences, 20, 1089–1111, https://doi.org/10.5194/bg-20-1089-2023, https://doi.org/10.5194/bg-20-1089-2023, 2023
Short summary
Short summary
The impact of assimilating different dataset combinations on regional to global-scale C budgets is explored with the ORCHIDEE model. Assimilating simultaneously multiple datasets is preferable to optimize the values of the model parameters and avoid model overfitting. The challenges in constraining soil C disequilibrium using atmospheric CO2 data are highlighted for an accurate prediction of the land sink distribution.
Matti Kämäräinen, Juha-Pekka Tuovinen, Markku Kulmala, Ivan Mammarella, Juha Aalto, Henriikka Vekuri, Annalea Lohila, and Anna Lintunen
Biogeosciences, 20, 897–909, https://doi.org/10.5194/bg-20-897-2023, https://doi.org/10.5194/bg-20-897-2023, 2023
Short summary
Short summary
In this study, we introduce a new method for modeling the exchange of carbon between the atmosphere and a study site located in a boreal forest in southern Finland. Our method yields more accurate results than previous approaches in this context. Accurately estimating carbon exchange is crucial for gaining a better understanding of the role of forests in regulating atmospheric carbon and addressing climate change.
Stéphanie Barrillon, Robin Fuchs, Anne A. Petrenko, Caroline Comby, Anthony Bosse, Christophe Yohia, Jean-Luc Fuda, Nagib Bhairy, Frédéric Cyr, Andrea M. Doglioli, Gérald Grégori, Roxane Tzortzis, Francesco d'Ovidio, and Melilotus Thyssen
Biogeosciences, 20, 141–161, https://doi.org/10.5194/bg-20-141-2023, https://doi.org/10.5194/bg-20-141-2023, 2023
Short summary
Short summary
Extreme weather events can have a major impact on ocean physics and biogeochemistry, but their study is challenging. In May 2019, an intense storm occurred in the north-western Mediterranean Sea, during which in situ multi-platform measurements were performed. The results show a strong impact on the surface phytoplankton, highlighting the need for high-resolution measurements coupling physics and biology during these violent events that may become more common in the context of global change.
Darren C. McKee, Scott C. Doney, Alice Della Penna, Emmanuel S. Boss, Peter Gaube, Michael J. Behrenfeld, and David M. Glover
Biogeosciences, 19, 5927–5952, https://doi.org/10.5194/bg-19-5927-2022, https://doi.org/10.5194/bg-19-5927-2022, 2022
Short summary
Short summary
As phytoplankton (small, drifting photosynthetic organisms) drift with ocean currents, biomass accumulation rates should be evaluated in a Lagrangian (observer moves with a fluid parcel) as opposed to an Eulerian (observer is stationary) framework. Here, we use profiling floats and surface drifters combined with satellite data to analyse time and length scales of chlorophyll concentrations (a proxy for biomass) and of velocity to quantify how phytoplankton variability is related to water motion.
Karo Michaelian and Aleksandar Simeonov
Biogeosciences, 19, 4029–4034, https://doi.org/10.5194/bg-19-4029-2022, https://doi.org/10.5194/bg-19-4029-2022, 2022
Short summary
Short summary
We reply to Lars Björn's critique of our article concerning the importance of photon dissipation to the origin and evolution of the biosphere. Björn doubts our assertion that organic pigments, ecosystems, and the biosphere arose out of a non-equilibrium thermodynamic imperative to increase global photon dissipation. He shows that the albedo of some non-living material is less than that of living material. We point out, however, that photon dissipation involves other factors besides albedo.
Reint Fischer, Delphine Lobelle, Merel Kooi, Albert Koelmans, Victor Onink, Charlotte Laufkötter, Linda Amaral-Zettler, Andrew Yool, and Erik van Sebille
Biogeosciences, 19, 2211–2234, https://doi.org/10.5194/bg-19-2211-2022, https://doi.org/10.5194/bg-19-2211-2022, 2022
Short summary
Short summary
Since current estimates show that only about 1 % of the all plastic that enters the ocean is floating at the surface, we look at subsurface processes that can cause vertical movement of (micro)plastic. We investigate how modelled algal attachment and the ocean's vertical movement can cause particles to sink and oscillate in the open ocean. Particles can sink to depths of > 5000 m in regions with high wind intensity and mainly remain close to the surface with low winds and biological activity.
Michelle Viswanathan, Tobias K. D. Weber, Sebastian Gayler, Juliane Mai, and Thilo Streck
Biogeosciences, 19, 2187–2209, https://doi.org/10.5194/bg-19-2187-2022, https://doi.org/10.5194/bg-19-2187-2022, 2022
Short summary
Short summary
We analysed the evolution of model parameter uncertainty and prediction error as we updated parameters of a maize phenology model based on yearly observations, by sequentially applying Bayesian calibration. Although parameter uncertainty was reduced, prediction quality deteriorated when calibration and prediction data were from different maize ripening groups or temperature conditions. The study highlights that Bayesian methods should account for model limitations and inherent data structures.
Jessica Kolbusz, Tim Langlois, Charitha Pattiaratchi, and Simon de Lestang
Biogeosciences, 19, 517–539, https://doi.org/10.5194/bg-19-517-2022, https://doi.org/10.5194/bg-19-517-2022, 2022
Short summary
Short summary
Western rock lobster larvae spend up to 11 months in offshore waters before ocean currents and their ability to swim transport them back to the coast. In 2008, there was a reduction in the number of puerulus (larvae) settling into the fishery. We use an oceanographic model to see how the environment may have contributed to the reduction. Our results show that a combination of effects from local currents and a widespread quiet period in the ocean off WA likely led to less puerulus settlement.
Rémy Asselot, Frank Lunkeit, Philip B. Holden, and Inga Hense
Biogeosciences, 19, 223–239, https://doi.org/10.5194/bg-19-223-2022, https://doi.org/10.5194/bg-19-223-2022, 2022
Short summary
Short summary
Previous studies show that phytoplankton light absorption can warm the atmosphere, but how this warming occurs is still unknown. We compare the importance of air–sea heat versus CO2 flux in the phytoplankton-induced atmospheric warming and determine the main driver. To shed light on this research question, we conduct simulations with a climate model of intermediate complexity. We show that phytoplankton mainly warms the atmosphere by increasing the air–sea CO2 flux.
Roxane Tzortzis, Andrea M. Doglioli, Stéphanie Barrillon, Anne A. Petrenko, Francesco d'Ovidio, Lloyd Izard, Melilotus Thyssen, Ananda Pascual, Bàrbara Barceló-Llull, Frédéric Cyr, Marc Tedetti, Nagib Bhairy, Pierre Garreau, Franck Dumas, and Gérald Gregori
Biogeosciences, 18, 6455–6477, https://doi.org/10.5194/bg-18-6455-2021, https://doi.org/10.5194/bg-18-6455-2021, 2021
Short summary
Short summary
This work analyzes an original high-resolution data set collected in the Mediterranean Sea. The major result is the impact of a fine-scale frontal structure on the distribution of phytoplankton groups, in an area of moderate energy with oligotrophic conditions. Our results provide an in situ confirmation of the findings obtained by previous modeling studies and remote sensing about the structuring effect of the fine-scale ocean dynamics on the structure of the phytoplankton community.
Johannes Vogel, Eva Paton, and Valentin Aich
Biogeosciences, 18, 5903–5927, https://doi.org/10.5194/bg-18-5903-2021, https://doi.org/10.5194/bg-18-5903-2021, 2021
Short summary
Short summary
This study investigates extreme ecosystem impacts evoked by temperature and soil moisture in the Mediterranean Basin for the time span 1999–2019 with a specific focus on seasonal variations. The analysis showed that ecosystem vulnerability is caused by several varying combinations of both drivers during the yearly cycle. The approach presented here helps to provide insights on the specific phenological stage of the year in which ecosystem vulnerability to a certain climatic condition occurs.
Mara Freilich, Alexandre Mignot, Glenn Flierl, and Raffaele Ferrari
Biogeosciences, 18, 5595–5607, https://doi.org/10.5194/bg-18-5595-2021, https://doi.org/10.5194/bg-18-5595-2021, 2021
Short summary
Short summary
Observations reveal that in some regions phytoplankton biomass increases during the wintertime when growth conditions are sub-optimal, which has been attributed to a release from grazing during mixed layer deepening. Measurements of grazer populations to support this theory are lacking. We demonstrate that a release from grazing when the winter mixed layer is deepening holds only for certain grazing models, extending the use of phytoplankton observations to make inferences about grazer dynamics.
Shuangling Chen, Mark L. Wells, Rui Xin Huang, Huijie Xue, Jingyuan Xi, and Fei Chai
Biogeosciences, 18, 5539–5554, https://doi.org/10.5194/bg-18-5539-2021, https://doi.org/10.5194/bg-18-5539-2021, 2021
Short summary
Short summary
Subduction transports surface waters to the oceanic interior, which can supply significant amounts of carbon and oxygen to the twilight zone. Using a novel BGC-Argo dataset covering the western North Pacific, we successfully identified the imprints of episodic shallow subduction patches. These subduction patches were observed mainly in spring and summer (70.6 %), and roughly half of them extended below ~ 450 m, injecting carbon- and oxygen-enriched waters into the ocean interior.
Pierre Damien, Julio Sheinbaum, Orens Pasqueron de Fommervault, Julien Jouanno, Lorena Linacre, and Olaf Duteil
Biogeosciences, 18, 4281–4303, https://doi.org/10.5194/bg-18-4281-2021, https://doi.org/10.5194/bg-18-4281-2021, 2021
Short summary
Short summary
The Gulf of Mexico deep waters are relatively poor in phytoplankton biomass due to low levels of nutrients in the upper layers. Using modeling techniques, we find that the long-living anticyclonic Loop Current eddies that are shed episodically from the Yucatan Channel strongly shape the distribution of phytoplankton and, more importantly, stimulate their growth. This results from the contribution of multiple mechanisms of physical–biogeochemical interactions discussed in this study.
Sergey V. Stanichny, Elena A. Kubryakova, and Arseny A. Kubryakov
Biogeosciences, 18, 3173–3188, https://doi.org/10.5194/bg-18-3173-2021, https://doi.org/10.5194/bg-18-3173-2021, 2021
Short summary
Short summary
In this paper, we show that the short-term impact of tropical cyclones can trigger the intense, long-term bloom of coccolithophores, which are major marine calcifiers playing an important role in the balance and fluxes of inorganic carbon in the ocean. In our paper, we describe the evolution of and physical reasons for such an unusual bloom observed in autumn 2005 in the Black Sea on the basis of satellite data.
Fengshan Liu, Ying Chen, Nini Bai, Dengpan Xiao, Huizi Bai, Fulu Tao, and Quansheng Ge
Biogeosciences, 18, 2275–2287, https://doi.org/10.5194/bg-18-2275-2021, https://doi.org/10.5194/bg-18-2275-2021, 2021
Short summary
Short summary
The sowing date is key to the surface biophysical processes in the winter dormancy period. The climate effect of the sowing date shift is therefore very interesting and may contribute to the mitigation of climate change. An earlier sowing date always had a higher LAI but a higher temperature in the dormancy period and a lower temperature in the growth period. The main reason was the relative contributions of the surface albedo and energy partitioning processes.
Peter Aartsma, Johan Asplund, Arvid Odland, Stefanie Reinhardt, and Hans Renssen
Biogeosciences, 18, 1577–1599, https://doi.org/10.5194/bg-18-1577-2021, https://doi.org/10.5194/bg-18-1577-2021, 2021
Short summary
Short summary
In the literature, it is generally assumed that alpine lichen heaths keep their direct environment cool due to their relatively high albedo. However, we reveal that the soil temperature and soil heat flux are higher below lichens than below shrubs during the growing season, despite a lower net radiation for lichens. We also show that the differences in microclimatic conditions between these two vegetation types are more pronounced during warm and sunny days than during cold and cloudy days.
Oleg Sizov, Ekaterina Ezhova, Petr Tsymbarovich, Andrey Soromotin, Nikolay Prihod'ko, Tuukka Petäjä, Sergej Zilitinkevich, Markku Kulmala, Jaana Bäck, and Kajar Köster
Biogeosciences, 18, 207–228, https://doi.org/10.5194/bg-18-207-2021, https://doi.org/10.5194/bg-18-207-2021, 2021
Short summary
Short summary
In changing climate, tundra is expected to turn into shrubs and trees, diminishing reindeer pasture and increasing risks of tick-borne diseases. However, this transition may require a disturbance. Fires in Siberia are increasingly widespread. We studied wildfire dynamics and tundra–forest transition over 60 years in northwest Siberia near the Arctic Circle. Based on satellite data analysis, we found that transition occurs in 40 %–85 % of burned tundra compared to 5 %–15 % in non-disturbed areas.
Kaveh Purkiani, André Paul, Annemiek Vink, Maren Walter, Michael Schulz, and Matthias Haeckel
Biogeosciences, 17, 6527–6544, https://doi.org/10.5194/bg-17-6527-2020, https://doi.org/10.5194/bg-17-6527-2020, 2020
Short summary
Short summary
There has been a steady increase in interest in mining of deep-sea minerals in the eastern Pacific Ocean recently. The ocean state in this region is known to be highly influenced by rotating bodies of water (eddies), some of which can travel long distances in the ocean and impact the deeper layers of the ocean. Better insight into the variability of eddy activity in this region is of great help to mitigate the impact of the benthic ecosystem from future potential deep-sea mining activity.
Jing Yan, Nathaniel A. Bogie, and Teamrat A. Ghezzehei
Biogeosciences, 17, 6377–6392, https://doi.org/10.5194/bg-17-6377-2020, https://doi.org/10.5194/bg-17-6377-2020, 2020
Short summary
Short summary
An uneven supply of water and nutrients in soils often drives how plants behave. We observed that plants extract all their required nutrients from dry soil patches in sufficient quantity, provided adequate water is available elsewhere in the root zone. Roots in nutrient-rich dry patches facilitate the nutrient acquisition by extensive growth, water release, and modifying water retention in their immediate environment. The findings are valuable in managing nutrient losses in agricultural systems.
Onur Kerimoglu, Yoana G. Voynova, Fatemeh Chegini, Holger Brix, Ulrich Callies, Richard Hofmeister, Knut Klingbeil, Corinna Schrum, and Justus E. E. van Beusekom
Biogeosciences, 17, 5097–5127, https://doi.org/10.5194/bg-17-5097-2020, https://doi.org/10.5194/bg-17-5097-2020, 2020
Short summary
Short summary
In this study, using extensive field observations and a numerical model, we analyzed the physical and biogeochemical structure of a coastal system following an extreme flood event. Our results suggest that a number of anomalous observations were driven by a co-occurrence of peculiar meteorological conditions and increased riverine discharges. Our results call for attention to the combined effects of hydrological and meteorological extremes that are anticipated to increase in frequency.
Amandine Erktan, Matthias C. Rillig, Andrea Carminati, Alexandre Jousset, and Stefan Scheu
Biogeosciences, 17, 4961–4980, https://doi.org/10.5194/bg-17-4961-2020, https://doi.org/10.5194/bg-17-4961-2020, 2020
Short summary
Short summary
Soil aggregation is crucial for soil functioning. While the role of bacteria and fungi in soil aggregation is well established, how predators feeding on microbes modify soil aggregation has hardly been investigated. We showed for the first time that protists modify soil aggregation, presumably through changes in the production of bacterial mucilage, and that collembolans reduce soil aggregation, presumably by reducing the abundance of saprotrophic fungi.
Wei Hu, Kotaro Murata, Chunlan Fan, Shu Huang, Hiromi Matsusaki, Pingqing Fu, and Daizhou Zhang
Biogeosciences, 17, 4477–4487, https://doi.org/10.5194/bg-17-4477-2020, https://doi.org/10.5194/bg-17-4477-2020, 2020
Short summary
Short summary
This paper reports the first estimate of the status of bacteria in long-distance-transported Asian dust, demonstrating that airborne dust, which can carry viable and nonviable bacteria on particle surfaces, is an efficient medium for constantly spreading bacteria at regional and even global scales. Such data are essential to better model and understand the roles and activities of bioaerosols in environmental evolution and climate change and the potential risks of bioaerosols to human health.
Inge Grünberg, Evan J. Wilcox, Simon Zwieback, Philip Marsh, and Julia Boike
Biogeosciences, 17, 4261–4279, https://doi.org/10.5194/bg-17-4261-2020, https://doi.org/10.5194/bg-17-4261-2020, 2020
Short summary
Short summary
Based on topsoil temperature data for different vegetation types at a low Arctic tundra site, we found large small-scale variability. Winter temperatures were strongly influenced by vegetation through its effects on snow. Summer temperatures were similar below most vegetation types and not consistently related to late summer permafrost thaw depth. Given that vegetation type defines the relationship between winter and summer soil temperature and thaw depth, it controls permafrost vulnerability.
Long Jiang, Theo Gerkema, Jacco C. Kromkamp, Daphne van der Wal, Pedro Manuel Carrasco De La Cruz, and Karline Soetaert
Biogeosciences, 17, 4135–4152, https://doi.org/10.5194/bg-17-4135-2020, https://doi.org/10.5194/bg-17-4135-2020, 2020
Short summary
Short summary
A seaward increasing chlorophyll-a gradient is observed during the spring bloom in a Dutch tidal bay. Biophysical model runs indicate the roles of bivalve grazing and tidal import in shaping the gradient. Five common spatial phytoplankton patterns are summarized in global estuarine–coastal ecosystems: seaward increasing, seaward decreasing, concave with a chlorophyll maximum, weak spatial gradients, and irregular patterns.
Emil De Borger, Justin Tiano, Ulrike Braeckman, Tom Ysebaert, and Karline Soetaert
Biogeosciences, 17, 1701–1715, https://doi.org/10.5194/bg-17-1701-2020, https://doi.org/10.5194/bg-17-1701-2020, 2020
Short summary
Short summary
By applying a novel technique to quantify organism-induced sediment–water column fluid exchange (bioirrigation), we show that organisms in subtidal (permanently submerged) areas have similar bioirrigation rates as those that inhabit intertidal areas (not permanently submerged), but organisms in the latter irrigate deeper burrows in this study. Our results expand on traditional methods to quantify bioirrigation rates and broaden the pool of field measurements of bioirrigation rates.
Sheila N. Estrada-Allis, Julio Sheinbaum Pardo, Joao M. Azevedo Correia de Souza, Cecilia Elizabeth Enríquez Ortiz, Ismael Mariño Tapia, and Jorge A. Herrera-Silveira
Biogeosciences, 17, 1087–1111, https://doi.org/10.5194/bg-17-1087-2020, https://doi.org/10.5194/bg-17-1087-2020, 2020
Short summary
Short summary
Continental shelves are the most productive areas in the ocean and can have an important impact on the nutrient cycle as well as the climate system. The one in Yucatán is the largest shelf in the Gulf of Mexico. However, its nutrient budget remains unidentifiable. Here we propose not only a general nutrient budget for the Yucatán Shelf but also the physical processes responsible for its pathway modulation through a physical–biogeochemical coupled model of the whole Gulf of Mexico.
Ashley Dubnick, Martin Sharp, Brad Danielson, Alireza Saidi-Mehrabad, and Joel Barker
Biogeosciences, 17, 963–977, https://doi.org/10.5194/bg-17-963-2020, https://doi.org/10.5194/bg-17-963-2020, 2020
Short summary
Short summary
We found that glaciers with basal temperatures near the melting point mobilize more solutes, nutrients, and microbes from the underlying substrate and are more likely to promote in situ biogeochemical activity than glaciers with basal temperatures well below the melting point. The temperature at the base of glaciers is therefore an important control on the biogeochemistry of ice near glacier beds, and, ultimately, the potential solutes, nutrients, and microbes exported from glaciated watersheds.
Audrey Delpech, Anna Conchon, Olivier Titaud, and Patrick Lehodey
Biogeosciences, 17, 833–850, https://doi.org/10.5194/bg-17-833-2020, https://doi.org/10.5194/bg-17-833-2020, 2020
Short summary
Short summary
Micronekton is an important, yet poorly known, component of the trophic chain, which partly contributes to the storage of CO2 in the deep ocean thanks to biomass vertical migrations. In this study, we characterize the ideal sampling regions to estimate the amount of biomass that undergoes theses migrations. We find that observations made in warm, nondynamic and productive waters reduce the error of the estimation by 20 %. This result should likely serve for future in situ network deployment.
Filippos Tagklis, Takamitsu Ito, and Annalisa Bracco
Biogeosciences, 17, 231–244, https://doi.org/10.5194/bg-17-231-2020, https://doi.org/10.5194/bg-17-231-2020, 2020
Short summary
Short summary
Deoxygenation of the oceans is potentially one of the most severe ecosystem stressors resulting from global warming given the high sensitivity of dissolved oxygen to ocean temperatures. Climate models suggest that despite the thermodynamic tendency of the oceans to lose oxygen, certain regions experience significant changes in the biologically driven O2 consumption, resulting in a resistance against deoxygenation. Overturning circulation changes are responsible for such a behavior.
Mohammad Abdul Halim, Han Y. H. Chen, and Sean C. Thomas
Biogeosciences, 16, 4357–4375, https://doi.org/10.5194/bg-16-4357-2019, https://doi.org/10.5194/bg-16-4357-2019, 2019
Short summary
Short summary
Using field data collected over 4 years across a range of stand ages, we investigated how seasonal surface albedo in boreal forest varies with stand age, stand structure, and composition. Our results indicate that successional change in species composition is a key driver of age–related patterns in albedo, with hardwood species associated with higher albedo. The patterns described have important implications for both climate modeling and
climate–smartboreal forest management.
Paul A. Moore, Maxwell C. Lukenbach, Dan K. Thompson, Nick Kettridge, Gustaf Granath, and James M. Waddington
Biogeosciences, 16, 3491–3506, https://doi.org/10.5194/bg-16-3491-2019, https://doi.org/10.5194/bg-16-3491-2019, 2019
Short summary
Short summary
Using very-high-resolution digital elevation models (DEMs), we assessed the basic structure and microtopographic variability of hummock–hollow plots at boreal and hemi-boreal sites primarily in North America. Using a simple model of peatland biogeochemical function, our results suggest that both surface heating and moss productivity may not be adequately resolved in models which only consider idealized hummock–hollow units.
Renee K. Gruber, Ryan J. Lowe, and James L. Falter
Biogeosciences, 16, 1921–1935, https://doi.org/10.5194/bg-16-1921-2019, https://doi.org/10.5194/bg-16-1921-2019, 2019
Short summary
Short summary
Researchers from the University of Western Australia's Oceans Institute are studying large tides (up to 12 m range) that occur in the Kimberley region of Australia. These tides flush coral reefs with water rich in nutrients, which supports the growth of reef organisms. In this paper, we show how tidal cycles and seasons control nutrient availability on reefs. This study is among the first published accounts of reefs and water quality data in the remote and pristine Kimberley region.
Sergey A. Marakushev and Ol'ga V. Belonogova
Biogeosciences, 16, 1817–1828, https://doi.org/10.5194/bg-16-1817-2019, https://doi.org/10.5194/bg-16-1817-2019, 2019
Short summary
Short summary
Among the existing theories of the autotrophic origin of life, CO2 is usually considered to be the carbon source for nascent autotrophic metabolism. However, ancestral carbon used in metabolism may have been derived from CH4 if the outflow of magma fluid to the surface of the Earth consisted mainly of methane. The hydrothermal system model is considered in the form of a phase diagram, which demonstrates the area of redox and P and T conditions favorable to development of primary methanotroph.
Venugopal Thushara, Puthenveettil Narayana Menon Vinayachandran, Adrian J. Matthews, Benjamin G. M. Webber, and Bastien Y. Queste
Biogeosciences, 16, 1447–1468, https://doi.org/10.5194/bg-16-1447-2019, https://doi.org/10.5194/bg-16-1447-2019, 2019
Short summary
Short summary
Chlorophyll distribution in the ocean remains to be explored in detail, despite its climatic significance. Here, we document the vertical structure of chlorophyll in the Bay of Bengal using observations and a model. The shape of chlorophyll profiles, characterized by prominent deep chlorophyll maxima, varies in dynamically different regions, controlled by the monsoonal forcings. The present study provides new insights into the vertical distribution of chlorophyll, rarely observed by satellites.
Cited articles
Altabet, M. A., Ryabenko, E., Stramma, L., Wallace, D. W. R., Frank, M., Grasse, P., and Lavik, G.: An eddy-stimulated hotspot for fixed nitrogen-loss from the Peru oxygen minimum zone, Biogeosciences, 9, 4897–4908, https://doi.org/10.5194/bg-9-4897-2012, 2012.
Carton J. A. and Giese, B. S.: A Reanalysis of Ocean Climate Using Simple Ocean Data Assimilation (SODA), Am. Meteorol. Soc., 136, 2999–3017, https://doi.org/10.1175/2007MWR1978.1, 2008.
Chaigneau, A., Gizolme, A., and Grados, C.: Mesoscale eddies off Peru in altimeter records: Identification algorithms and eddy spatio-temporal patterns, Prog. Oceanogr., 79, 106–119, https://doi.org/10.1016/j.pocean.2008.10.013, 2008.
Chaigneau, A., Texier, M., Eldin, G., Grados, C., and Pizarro, O.: Vertical structure of mesoscale eddies in the eastern South Pacific Ocean: A composite analysis from altimetry and Argo profiling floats, J. Geophys. Res., 116, 1–16, https://doi.org/10.1029/2011JC007134, 2011.
Chaigneau, A., Dominguez, N., Eldin, G., Vasquez, L., Flores, R., Grados, C., and Echevin, V.: Near-coastal circulation in the Northern Humboldt Current System from shipboard ADCP data, J. Geophys. Res., 118, 1–16, https://doi.org/10.1002/jgrc.20328, 2013.
Chavez, F. P., Bertrand, A., Guevara-Carrasco, R., Soler, P., and Csirke, J.: The northern Humboldt Current System: Brief history, present status and a view towards the future, Prog. Oceanogr., 79, 95–105, https://doi.org/10.1016/j.pocean.2008.10.012, 2008.
Chelton, D. B., Schlax, M. G., Samelson, R. M., and de Szoeke, R. A.: Global observations of large oceanic eddies, Geophys. Res. Lett., 34, 1–5, https://doi.org/10.1029/2007GL030812, 2007.
Chelton, D. B., Gaube, P., Schlax, M. G., Early, J. J., and Samelson, R. M.: The Influence of Nonlinear Mesoscale Eddies on Near-Surface Oceanic Chlorophyll, Science, 334, 328–332, https://doi.org/10.1126/science.1208897, 2011a.
Cipollini, P., Cromwell, D., Challenor, P. G., and Raffaglio, S.: Rossby waves detected in global ocean colour data, Geophys. Res. Lett., 28, 323–326, 2001.
Codispoti, L. A. and Christensen, J. P.: Nitrification, denitrification and nitrous oxide cycling in the eastern tropical South Pacific Ocean, Mar. Chem., 16, 277–300, 1985.
Colas, F., McWilliams, J. C., Capet, X., and Kurian, J.: Heat balance and eddies in the Peru-Chile current system, Clim. Dynam., 39, 509–529, 2012.
Czeschel, R., Stramma, L., Schwarzkopf, F. U., Giese, B. S., Funk, A., and Karstensen, J.: Middepth circulation of the eastern tropical South Pacific and its link to the oxygen minimum zone, J. Geophys. Res., 116, 1–13, https://doi.org/10.1029/2010JC006565, 2011.
Czeschel, R., Stramma, L., Weller, R. A., and Fischer, T.: Circulation, eddies, oxygen, and nutrient changes in the eastern tropical South Pacific Ocean, Ocean Sci., 11, 455–470, https://doi.org/10.5194/os-11-455-2015, 2015.
Debreu, L., Marchesiello, P., Penven, P., and Cambon, G.: Two-way nesting in split-explicit ocean models: algorithms, implementation and validation, Ocean Model., 49–50, 1–21, 2012.
Dietze, H., Matear, R., and Moore, T.: Nutrient supply to anticyclonic meso-scale eddies off western Austrailia estimated with artificial tracers released in a circulation model, Deep-Sea Res. Pt. I, 56, 1440–1448, https://doi.org/10.1016/j.dsr.2009.04.012, 2009.
Falkowski, P., Ziemann, D., Kolber, Z., and Bienfang, P.: Role of eddy pumping in enhancing primary production in the ocean, Nature, 352, 55–58, 1991.
Farías, L., Castro-González, M., Cornejo, M., Charpentier, J., Faúndez, J., Boontanon, N., and Yoshida, N.: Denitrification and nitrous oxide cycling within the upper oxycline of the eastern tropical South Pacific oxygen minimum zone, Limnol. Oceanogr., 54, 132–144, 2009.
Gutknecht, E., Dadou, I., Le Vu, B., Cambon, G., Sudre, J., Garçon, V., Machu, E., Rixen, T., Kock, A., Flohr, A., Paulmier, A., and Lavik, G.: Coupled physical/biogeochemical modeling including O2-dependent processes in the Eastern Boundary Upwelling Systems: application in the Benguela, Biogeosciences, 10, 3559–3591, https://doi.org/10.5194/bg-10-3559-2013, 2013.
Halo, I., Backeberg, B., Penven, P., Reason, C., Ansorge, I., and Ulgren, J.: Eddy properties in the Mozambique Channel: A comparison between satellite altimetry and Ocean Circulation models, Deep-Sea Res. Pt. II, 100, 119–135, https://doi.org/10.1016/j.dsr2.2013.10.015, 2014.
Hamersley, M. R., Lavik, G., Woebken, D., Rattray, J. E., Lam, P., Hopmans, E. C., Damste, J. S. S., Krüger, S., Graco, M., Gutiérrez, D., and Kuypers, M.: Anaerobic ammonium oxidation in the Peruvian oxygen minimum zone, Limnol. Oceanogr., 52, 923–933, 2007.
Holte, J., Straneo, F., Moffat, C., Weller, R., and Farrar, J. T.: Structure and surface properties of eddies in the southeast Pacific Ocean, J. Geophys. Res.-Oceans, 118, 119–135, https://doi.org/10.1002/jgrc.20175, 2013.
Hutchins, D. A., Hare, C. E., Weaver, R. S., Zhang, Y., Firme, G. F., DiTullio, G. R., Alm, M. B., Riseman, S. F., Maucher, J. M., Geesey, M. E., Trick, C. G., Smith, G. J., Rue, E. L., Conn, J., and Bruland, K. W.: Phytoplankton iron limitation in the Humboldt Current and Peru Upwelling, Limnol. Oceanogr., 47, 997–1011, 2002.
IOC, IHO and BODC: Centenary Edition of the GEBCO Digital Atlas, published on CD-ROM on behalf of the Intergovernmental Oceanographic Commission and the International Hydrographic Organization as part of the General Bathymetric Chart of the Oceans, British Oceanographic Data Centre, Liverpool, 2003.
Jenkins, W.: Nitrate flux into the euphotic zone near Bermuda, Nature, 331, 521–523, 1988.
José, Y. S., Aumont, O., Machu, E., Penven, P., Moloney, C. L., and Maury, O.: Influence of mesoscale eddies on biological production in the Mozambique Channel: Several contrasted examples from a coupled ocean-biogeochemistry Model, Deep-Sea Res. Pt. II, 100, 79–93, https://doi.org/10.1016/j.dsr2.2013.10.018, 2014.
Kalvelage, K., Lavik, G., Lam, P., Contreras, S., Arteaga, L., Löscher, C. R., Oschlies, A., Paulmier, A., Stramma, L., and Kuypers, M. M. M.: Nitrogen cycling driven by organic matter export in the South Pacific oxygen minimum zone, Nat. Geosci., 6, 228–234, https://doi.org/10.1038/NGEO1739, 2013.
Karstensen, J., Fiedler, B., Schütte, F., Brandt, P., Körtzinger, A., Fischer, G., Zantopp, R., Hahn, J., Visbeck, M., and Wallace, D.: Open ocean dead zones in the tropical North Atlantic Ocean, Biogeosciences, 12, 2597–2605, https://doi.org/10.5194/bg-12-2597-2015, 2015.
Lam, P., Lavik, G., Jensen, M. M., van de Vossenberg, J., Schmid, M., Woebken, D., Gutiérrez, D., Amann, R., Jetten, M. S. M., and Kuypers, M. M.: Revising the nitrogen cycle in the Peruvian oxygen minimum zone, P. Natl. Acad. Sci., 106, 4752–4757, https://doi.org/10.1073/pnas.0812444106, 2009.
Lévy, M., Klein, P., and Treguier, A. M.: Impact of sub-mesoscale physics on production and subduction of phytoplankton in an oligotrophic regime, J. Mar. Res., 59, 535–565, 2001.
Liu, W. T., Tang, W., and Polito, P. S.: NASA scatterometer provides global ocean-surface wind fields with more structures than numerical weather prediction, Geophys. Res. Lett., 25, 761–764, 1998.
Mahadevan, A. and Archer, D.: Modelling the impact of fronts and mesoscale circulation on the nutrient supphy and biogeochemistry of the upper ocean, J. Geophys. Res., 105, 1209–1225, 2000.
Martin, A. and Richards, K.: Mechanism for vertical nutrient transport within a North Atlantic mesoscale eddy, Deep-Sea Res. Pt. II, 48, 757–773, 2001.
Morel, A. and Berthon, J. F.: Surface pigments, algal biomass profiles, and potential production of the euphotic layer: Relationships reinvestigated in view of remote-sensing applications, Limnol. Oceanogr., 34, 1545–1562, 1989.
O'Reilly, J. E., Maritorena, S., Mitchell, B. G., Siegel, D. A., Carder, K. L., Garver, S. A., Kahru, M., and McClain, C.: Ocean color chlorophyll algorithms for SeaWiFS, J. Geophys. Res., 103, 24937–24953, 1998.
Ridgway, K. R., Dunn, J. R., and Wilkin, J. L.: Ocean interpolation by four-dimensional weighted least Squares-Application to the waters around Australasia, J. Atmos. Ocean. Tech., 19, 1357–1375, 2002.
Saraceno, M., Strub, P. T., and Kosro, P. M.: Estimates of sea surface height and near-surface alongshore coastal currents from combinations of altimeters and tide gauges, J. Geophys. Res., 113, 1–20, https://doi.org/10.1029/2008JC004756, 2008.
Shchepetkin, A. F. and McWilliams, J. C.: The regional oceanic modeling system (ROMS): a split-explicit, free-surface, topography-following-coordinate oceanic model, Ocean Model., 19, 347–404, 2005.
Smith, R. L.: Peru Coastal Currents During El Niño: 1976 and 1982, Science, 221, 1397–1399, https://doi.org/10.1126/science.221.4618.1397, 1983.
Stramma, L., Bange, H. W., Czeschel, R., Lorenzo, A., and Frank, M.: On the role of mesoscale eddies for the biological productivity and biogeochemistry in the eastern tropical Pacific Ocean off Peru, Biogeosciences, 10, 7293–7306, https://doi.org/10.5194/bg-10-7293-2013, 2013.
Stramma, L., Weller, R. A., Czeschel, R., and Bigorre, S.: Eddies and an extreme water mass anomaly observed in the eastern south Pacific at the Stratus mooring, J. Geophys. Res.-Oceans, 119, 1068–1083, https://doi.org/10.1002/2013JC009470, 2014.
Strub, T.: High-Resolution Ocean Topography Science Requirements for Coastal Studies, in: The Report of the High-resolution Ocean Topography Science Working Group meeting, edited by: Chelton, D. B., Ref. 2001-4, College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis, OR, 224 pp., 2001.
Thomsen, S., Kanzow, T., Krahmann, G., Greatbatch, R. J., Dengler, M., and Lavik, G.: The formation of a subsurface anticyclonic eddy in the Peru-Chile Undercurrent and its impact on the near-coastal salinity, oxygen, and nutrient distributions, J. Geophys. Res.-Oceans, 120, 476–501, https://doi.org/10.1002/2015JC010878, 2016.
Ward, B. B., Devol, A. H., Rich, J. J., Chang, B. X., Bulow, S. E., Naik, H., Pratihary, A., and Jayakumar, A.: Denitrification as the dominant nitrogen loss process in the Arabian Sea, Nat. Lett., 461, 78–82, https://doi.org/10.1038/nature08276, 2009.
Worley, S. J., Woodruff, S. D., Reynolds, R. W., Lubker, S. J., and Lott, N.: ICOADS release 2.1 data and products, Int. J. Climatol., 25, 823–842, 2005.
Zibordi, G., Meĺin, F., and Berthon, J. F.: Comparison of SeaWiFS, MODIS and MERIS radiometric products at a coastal site, Geophys. Res. Lett., 33, 1–4, https://doi.org/10.1029/2006GL025778, 2006.
Short summary
This study aims to investigate the diverse subsurface nutrient patterns observed within anticyclonic eddies in the upwelling system off Peru. Two simulated anticyclonic eddies with opposing subsurface nitrate concentrations were analysed. The results show that diverse nutrient patterns within anticyclonic eddies are related to the presence of water mass from different origins at different depths, responding to variations in depth of the circulation strength at the edge of the eddy.
This study aims to investigate the diverse subsurface nutrient patterns observed within...
Altmetrics
Final-revised paper
Preprint