Articles | Volume 23, issue 6
https://doi.org/10.5194/bg-23-2101-2026
© Author(s) 2026. 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-23-2101-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
26 Mar 2026
Research article | Highlight paper |
| 26 Mar 2026
| 26 Mar 2026
Wind-induced collapse of the biopolymeric surface microlayer induces sudden changes in sea surface roughness
GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany
Kiel University (CAU), Kiel, Germany
Gernot Friedrichs
Kiel University (CAU), Kiel, Germany
Institute of Physical Chemistry, Kiel, Germany
KMS Kiel Marine Science-Centre for Interdisciplinary Marine Science, Kiel University, Kiel, Germany
Kerstin E. Krall
Institute of Environmental Physics (IUP), Heidelberg University, Heidelberg, Germany
Bernd Jähne
Institute of Environmental Physics (IUP), Heidelberg University, Heidelberg, Germany
Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Heidelberg, Germany
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Evelyn Freney, Karine Sellegri, Therese Barthelmeß, Anja Engel, Darrel Baumgardner, and Dagen Hughes
EGUsphere, https://doi.org/10.5194/egusphere-2026-87, https://doi.org/10.5194/egusphere-2026-87, 2026
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
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The exchange of material between the ocean and atmosphere plays an important role in regulating Earth’s climate. Through wave action, the ocean releases tiny airborne particles that influence atmospheric processes. This study examines how biological and chemical processes in seawater affect the properties of particles emitted from the ocean, highlighting the complex links between ocean biology and marine aerosols.
Amavi Silva, Surandokht Nikzad, Theresa Barthelmeß, Anja Engel, Hartmut Herrmann, Manuela van Pinxteren, Kai Wirtz, Oliver Wurl, and Markus Schartau
Biogeosciences, 23, 1697–1718, https://doi.org/10.5194/bg-23-1697-2026, https://doi.org/10.5194/bg-23-1697-2026, 2026
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We conducted the first meta-analysis combining marine and freshwater studies to understand organic matter enrichment in the surface microlayer. Nitrogen-rich, particulate compounds are often enriched, with patterns varying by multiple factors. We recommend tracking both absolute concentrations and normalized enrichment patterns to better assess ecological conditions. Our study also introduces improved statistical methods for analyzing and comparing surface microlayer data.
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Biogeosciences, 23, 1261–1278, https://doi.org/10.5194/bg-23-1261-2026, https://doi.org/10.5194/bg-23-1261-2026, 2026
Short summary
Short summary
Carbon monoxide (CO), chromophoric dissolved organic matter (CDOM), and fluorescent dissolved organic matter (FDOM) were more frequently enriched in the higher temperature and salinity off-shore regions. Marine-humic like CDOM tends to inhibit the sea-to-air flux of CO in the sea-surface microlayer (SML). The enrichment and photochemical process of CO in the SML were more active during the daytime. The photochemical production and microbial consumption rates of CO in the SML were more active than in the subsurface layer (SSW).
Carsten Rauch, Lisa Deyle, Leonie Jaeger, Edgar Fernando Cortés-Espinoza, Mariana Ribas-Ribas, Josefine Karnatz, Anja Engel, and Oliver Wurl
Ocean Sci., 22, 403–426, https://doi.org/10.5194/os-22-403-2026, https://doi.org/10.5194/os-22-403-2026, 2026
Short summary
Short summary
Microsensors measuring oxygen and temperature were used to gain high-resolution profiles across the surface of a water basin, in which an algal bloom was induced. These novel data show that the oxygen at the sea surface is highly influenced by algal blooms, while the temperature is only indirectly affected by them. Since algal blooms occur globally, this has considerable implications for calculating global air-sea exchanges of gases or heat, especially under low-wind conditions.
Yuanxu Dong, Christa A. Marandino, Ryo Dobashi, David Ho, Gregor Rehder, Henry C. Bittig, Josefine Karnatz, Bita Sabbaghzadeh, Helen Czerski, and Anja Engel
EGUsphere, https://doi.org/10.5194/egusphere-2025-6095, https://doi.org/10.5194/egusphere-2025-6095, 2026
Short summary
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Air-sea gas exchange regulates the Earth's climate. However, the kinetic exchange process only uses wind speed to describe, neglecting other drivers. In this study, we investigate how fetch and natural surfactants modulate the air-sea carbon dioxide exchange. Measurements from the central Baltic Sea show that limited fetch and elevated surfactants significantly suppress this exchange. A new parameterization is provided, improving regional carbon budgets and evaluations of climate solutions.
Riaz Bibi, Mariana Ribas-Ribas, Leonie Jaeger, Carola Lehners, Lisa Gassen, Edgar Fernando Cortés-Espinoza, Jochen Wollschläger, Claudia Thölen, Hannelore Waska, Jasper Zöbelein, Thorsten Brinkhoff, Isha Athale, Rüdiger Röttgers, Michael Novak, Anja Engel, Theresa Barthelmeß, Josefine Karnatz, Thomas Reinthaler, Dmytro Spriahailo, Gernot Friedrichs, Falko Asmussen Schäfer, and Oliver Wurl
Biogeosciences, 22, 7563–7589, https://doi.org/10.5194/bg-22-7563-2025, https://doi.org/10.5194/bg-22-7563-2025, 2025
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A multidisciplinary mesocosm study was conducted to investigate biogeochemical processes and their relationships in the sea-surface microlayer and underlying water during an induced phytoplankton bloom. Phytoplankton-derived organic matter, fuelled microbial activity and biofilm formation, supporting high bacterial abundance. Distinct temporal patterns in biogeochemical parameters and greater variability in the sea-surface microlayer highlight its influence on air–sea interactions.
Josefine Karnatz, Theresa Barthelmeß, Bita Sabbaghzadeh, and Anja Engel
EGUsphere, https://doi.org/10.5194/egusphere-2025-5385, https://doi.org/10.5194/egusphere-2025-5385, 2025
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Cyanobacteria form massive summer blooms in the Baltic Sea that release organic compounds to the ocean’s surface. By analyzing the thin boundary layer between ocean and atmosphere, this study shows that cyanobacteria influence the molecular composition and surface properties of the sea surface, increasing surfactants that may reduce gas exchange. The findings provide new insight into how future cyanobacteria blooms could affect air-sea interactions and climate-related processes.
Anisbel Leon-Marcos, Moritz Zeising, Manuela van Pinxteren, Sebastian Zeppenfeld, Astrid Bracher, Elena Barbaro, Anja Engel, Matteo Feltracco, Ina Tegen, and Bernd Heinold
Geosci. Model Dev., 18, 4183–4213, https://doi.org/10.5194/gmd-18-4183-2025, https://doi.org/10.5194/gmd-18-4183-2025, 2025
Short summary
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This study represents the primary marine organic aerosol (PMOA) emissions, focusing on their sea–atmosphere transfer. Using the FESOM2.1–REcoM3 model, concentrations of key organic biomolecules were estimated and integrated into the ECHAM6.3–HAM2.3 aerosol–climate model. Results highlight the influence of marine biological activity and surface winds on PMOA emissions, with reasonably good agreement with observations improving aerosol representation in the southern oceans.
Karine Sellegri, Theresa Barthelmeß, Jonathan Trueblood, Antonia Cristi, Evelyn Freney, Clémence Rose, Neill Barr, Mike Harvey, Karl Safi, Stacy Deppeler, Karen Thompson, Wayne Dillon, Anja Engel, and Cliff Law
Atmos. Chem. Phys., 23, 12949–12964, https://doi.org/10.5194/acp-23-12949-2023, https://doi.org/10.5194/acp-23-12949-2023, 2023
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The amount of sea spray emitted to the atmosphere depends on the ocean temperature, but this dependency is not well understood, especially when ocean biology is involved. In this study, we show that sea spray emissions are increased by up to a factor of 4 at low seawater temperatures compared to moderate temperatures, and we quantify the temperature dependence as a function of the ocean biogeochemistry.
Manon Rocco, Erin Dunne, Alexia Saint-Macary, Maija Peltola, Theresa Barthelmeß, Neill Barr, Karl Safi, Andrew Marriner, Stacy Deppeler, James Harnwell, Anja Engel, Aurélie Colomb, Alfonso Saiz-Lopez, Mike Harvey, Cliff S. Law, and Karine Sellegri
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Preprint archived
Short summary
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During the Sea2cloud campaign in the Southern Pacific Ocean, we measured air-sea emissions from phytopankton of two key atmospheric compounds: DMS and MeSH. These compounds are well-known to play a great role in atmospheric chemistry and climate. We see in this paper that these compounds are most emited by the nanophytoplankton population. We provide here parameters for climate models to predict future trends of the emissions of these compounds and their roles and impacts on the global warming.
Lin Yang, Jing Zhang, Anja Engel, and Gui-Peng Yang
Biogeosciences, 19, 5251–5268, https://doi.org/10.5194/bg-19-5251-2022, https://doi.org/10.5194/bg-19-5251-2022, 2022
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Enrichment factors of dissolved organic matter (DOM) in the eastern marginal seas of China exhibited a significant spatio-temporal variation. Photochemical and enrichment processes co-regulated DOM enrichment in the sea-surface microlayer (SML). Autochthonous DOM was more frequently enriched in the SML than terrestrial DOM. DOM in the sub-surface water exhibited higher aromaticity than that in the SML.
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Biogeosciences, 19, 5199–5219, https://doi.org/10.5194/bg-19-5199-2022, https://doi.org/10.5194/bg-19-5199-2022, 2022
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Eddies are ubiquitous in the ocean and alter physical, chemical, and biological processes. However, how they affect organic carbon production and consumption is largely unknown. Here we show how an eddy triggers a cascade effect on biomass production and metabolic activities of phyto- and bacterioplankton. Our results may contribute to the improvement of biogeochemical models used to estimate carbon fluxes in the ocean.
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Greenhouse gases released by human activity cause a global rise in mean temperatures. While scientists can predict how much of these gases accumulate in the atmosphere based on not only human-derived sources but also oceanic sinks, it is rather difficult to predict the major influence of coastal ecosystems. We provide a detailed study on the occurrence, composition, and controls of substances that suppress gas exchange. We thus help to determine what controls coastal greenhouse gas fluxes.
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A class of marine particles (transparent exopolymer particles, TEPs) that is ubiquitously found in the world oceans was measured for the first time in ambient marine aerosol particles and marine cloud waters in the tropical Atlantic Ocean. TEPs are likely to have good properties for influencing clouds. We show that TEPs are transferred from the ocean to the marine atmosphere via sea-spray formation and our results suggest that they can also form directly in aerosol particles and in cloud water.
France Van Wambeke, Vincent Taillandier, Karine Desboeufs, Elvira Pulido-Villena, Julie Dinasquet, Anja Engel, Emilio Marañón, Céline Ridame, and Cécile Guieu
Biogeosciences, 18, 5699–5717, https://doi.org/10.5194/bg-18-5699-2021, https://doi.org/10.5194/bg-18-5699-2021, 2021
Short summary
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Simultaneous in situ measurements of (dry and wet) atmospheric deposition and biogeochemical stocks and fluxes in the sunlit waters of the open Mediterranean Sea revealed complex physical and biological processes occurring within the mixed layer. Nitrogen (N) budgets were computed to compare the sources and sinks of N in the mixed layer. The transitory effect observed after a wet dust deposition impacted the microbial food web down to the deep chlorophyll maximum.
Frédéric Gazeau, France Van Wambeke, Emilio Marañón, Maria Pérez-Lorenzo, Samir Alliouane, Christian Stolpe, Thierry Blasco, Nathalie Leblond, Birthe Zäncker, Anja Engel, Barbara Marie, Julie Dinasquet, and Cécile Guieu
Biogeosciences, 18, 5423–5446, https://doi.org/10.5194/bg-18-5423-2021, https://doi.org/10.5194/bg-18-5423-2021, 2021
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Our study shows that the impact of dust deposition on primary production depends on the initial composition and metabolic state of the tested community and is constrained by the amount of nutrients added, to sustain both the fast response of heterotrophic prokaryotes and the delayed one of phytoplankton. Under future environmental conditions, heterotrophic metabolism will be more impacted than primary production, therefore reducing the capacity of surface waters to sequester anthropogenic CO2.
Evelyn Freney, Karine Sellegri, Alessia Nicosia, Leah R. Williams, Matteo Rinaldi, Jonathan T. Trueblood, André S. H. Prévôt, Melilotus Thyssen, Gérald Grégori, Nils Haëntjens, Julie Dinasquet, Ingrid Obernosterer, France Van Wambeke, Anja Engel, Birthe Zäncker, Karine Desboeufs, Eija Asmi, Hilkka Timonen, and Cécile Guieu
Atmos. Chem. Phys., 21, 10625–10641, https://doi.org/10.5194/acp-21-10625-2021, https://doi.org/10.5194/acp-21-10625-2021, 2021
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In this work, we present observations of the organic aerosol content in primary sea spray aerosols (SSAs) continuously generated along a 5-week cruise in the Mediterranean. This information is combined with seawater biogeochemical properties also measured continuously along the ship track to develop a number of parametrizations that can be used in models to determine SSA organic content in oligotrophic waters that represent 60 % of the oceans from commonly measured seawater variables.
Gerd Krahmann, Damian L. Arévalo-Martínez, Andrew W. Dale, Marcus Dengler, Anja Engel, Nicolaas Glock, Patricia Grasse, Johannes Hahn, Helena Hauss, Mark Hopwood, Rainer Kiko, Alexandra Loginova, Carolin R. Löscher, Marie Maßmig, Alexandra-Sophie Roy, Renato Salvatteci, Stefan Sommer, Toste Tanhua, and Hela Mehrtens
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2020-308, https://doi.org/10.5194/essd-2020-308, 2021
Preprint withdrawn
Short summary
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The project "Climate-Biogeochemistry Interactions in the Tropical Ocean" (SFB 754) was a multidisciplinary research project active from 2008 to 2019 aimed at a better understanding of the coupling between the tropical climate and ocean circulation and the ocean's oxygen and nutrient balance. On 34 research cruises, mainly in the Southeast Tropical Pacific and the Northeast Tropical Atlantic, 1071 physical, chemical and biological data sets were collected.
France Van Wambeke, Elvira Pulido, Philippe Catala, Julie Dinasquet, Kahina Djaoudi, Anja Engel, Marc Garel, Sophie Guasco, Barbara Marie, Sandra Nunige, Vincent Taillandier, Birthe Zäncker, and Christian Tamburini
Biogeosciences, 18, 2301–2323, https://doi.org/10.5194/bg-18-2301-2021, https://doi.org/10.5194/bg-18-2301-2021, 2021
Short summary
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Michaelis–Menten kinetics were determined for alkaline phosphatase, aminopeptidase and β-glucosidase in the Mediterranean Sea. Although the ectoenzymatic-hydrolysis contribution to heterotrophic prokaryotic needs was high in terms of N, it was low in terms of C. This study points out the biases in interpretation of the relative differences in activities among the three tested enzymes in regard to the choice of added concentrations of fluorogenic substrates.
Evelyn Freney, Karine Sellegri, Therese Barthelmeß, Anja Engel, Darrel Baumgardner, and Dagen Hughes
EGUsphere, https://doi.org/10.5194/egusphere-2026-87, https://doi.org/10.5194/egusphere-2026-87, 2026
This preprint is open for discussion and under review for Biogeosciences (BG).
Short summary
Short summary
The exchange of material between the ocean and atmosphere plays an important role in regulating Earth’s climate. Through wave action, the ocean releases tiny airborne particles that influence atmospheric processes. This study examines how biological and chemical processes in seawater affect the properties of particles emitted from the ocean, highlighting the complex links between ocean biology and marine aerosols.
Amavi Silva, Surandokht Nikzad, Theresa Barthelmeß, Anja Engel, Hartmut Herrmann, Manuela van Pinxteren, Kai Wirtz, Oliver Wurl, and Markus Schartau
Biogeosciences, 23, 1697–1718, https://doi.org/10.5194/bg-23-1697-2026, https://doi.org/10.5194/bg-23-1697-2026, 2026
Short summary
Short summary
We conducted the first meta-analysis combining marine and freshwater studies to understand organic matter enrichment in the surface microlayer. Nitrogen-rich, particulate compounds are often enriched, with patterns varying by multiple factors. We recommend tracking both absolute concentrations and normalized enrichment patterns to better assess ecological conditions. Our study also introduces improved statistical methods for analyzing and comparing surface microlayer data.
Lin Yang, Bin Yang, Jing Zhang, Anja Engel, and Gui-Peng Yang
Biogeosciences, 23, 1261–1278, https://doi.org/10.5194/bg-23-1261-2026, https://doi.org/10.5194/bg-23-1261-2026, 2026
Short summary
Short summary
Carbon monoxide (CO), chromophoric dissolved organic matter (CDOM), and fluorescent dissolved organic matter (FDOM) were more frequently enriched in the higher temperature and salinity off-shore regions. Marine-humic like CDOM tends to inhibit the sea-to-air flux of CO in the sea-surface microlayer (SML). The enrichment and photochemical process of CO in the SML were more active during the daytime. The photochemical production and microbial consumption rates of CO in the SML were more active than in the subsurface layer (SSW).
Carsten Rauch, Lisa Deyle, Leonie Jaeger, Edgar Fernando Cortés-Espinoza, Mariana Ribas-Ribas, Josefine Karnatz, Anja Engel, and Oliver Wurl
Ocean Sci., 22, 403–426, https://doi.org/10.5194/os-22-403-2026, https://doi.org/10.5194/os-22-403-2026, 2026
Short summary
Short summary
Microsensors measuring oxygen and temperature were used to gain high-resolution profiles across the surface of a water basin, in which an algal bloom was induced. These novel data show that the oxygen at the sea surface is highly influenced by algal blooms, while the temperature is only indirectly affected by them. Since algal blooms occur globally, this has considerable implications for calculating global air-sea exchanges of gases or heat, especially under low-wind conditions.
Falko Asmussen-Schäfer, Mariana Ribas-Ribas, Oliver Wurl, and Gernot Friedrichs
EGUsphere, https://doi.org/10.5194/egusphere-2025-5276, https://doi.org/10.5194/egusphere-2025-5276, 2026
Short summary
Short summary
We developed a way to quantify how molecules accumulate at the ocean surface on a nanometer scale. Using laser spectroscopy and electrochemical methods, we measured how densely these molecular films cover the water surface. Such single-molecule-thick layers can greatly influence gas exchange between the ocean and the atmosphere. By comparing our results with existing data sets, we produced a first global estimate of potential film coverage.
Yuanxu Dong, Christa A. Marandino, Ryo Dobashi, David Ho, Gregor Rehder, Henry C. Bittig, Josefine Karnatz, Bita Sabbaghzadeh, Helen Czerski, and Anja Engel
EGUsphere, https://doi.org/10.5194/egusphere-2025-6095, https://doi.org/10.5194/egusphere-2025-6095, 2026
Short summary
Short summary
Air-sea gas exchange regulates the Earth's climate. However, the kinetic exchange process only uses wind speed to describe, neglecting other drivers. In this study, we investigate how fetch and natural surfactants modulate the air-sea carbon dioxide exchange. Measurements from the central Baltic Sea show that limited fetch and elevated surfactants significantly suppress this exchange. A new parameterization is provided, improving regional carbon budgets and evaluations of climate solutions.
Jasper Zöbelein, Shubham Sawle, Gernot Friedrichs, Mariana Ribas-Ribas, Carola Lehners, Katharina Paetz, Maximilian Pflaum, and Hannelore Waska
EGUsphere, https://doi.org/10.5194/egusphere-2025-6563, https://doi.org/10.5194/egusphere-2025-6563, 2026
Short summary
Short summary
The ocean is glazed with a one-millimetre biofilm that controls the flow of gases and energy from the atmosphere. To investigate how this film forms, we cultivated microscopic algae in a tank under controlled, windless conditions. Our results show that carbohydrates released by these algae rise to the surface, forming "carbo-slicks" that create this gel-like layer. This demonstrates that biological production is a key driver of the sea surface, which is crucial for understanding carbon exchange.
Riaz Bibi, Mariana Ribas-Ribas, Leonie Jaeger, Carola Lehners, Lisa Gassen, Edgar Fernando Cortés-Espinoza, Jochen Wollschläger, Claudia Thölen, Hannelore Waska, Jasper Zöbelein, Thorsten Brinkhoff, Isha Athale, Rüdiger Röttgers, Michael Novak, Anja Engel, Theresa Barthelmeß, Josefine Karnatz, Thomas Reinthaler, Dmytro Spriahailo, Gernot Friedrichs, Falko Asmussen Schäfer, and Oliver Wurl
Biogeosciences, 22, 7563–7589, https://doi.org/10.5194/bg-22-7563-2025, https://doi.org/10.5194/bg-22-7563-2025, 2025
Short summary
Short summary
A multidisciplinary mesocosm study was conducted to investigate biogeochemical processes and their relationships in the sea-surface microlayer and underlying water during an induced phytoplankton bloom. Phytoplankton-derived organic matter, fuelled microbial activity and biofilm formation, supporting high bacterial abundance. Distinct temporal patterns in biogeochemical parameters and greater variability in the sea-surface microlayer highlight its influence on air–sea interactions.
Josefine Karnatz, Theresa Barthelmeß, Bita Sabbaghzadeh, and Anja Engel
EGUsphere, https://doi.org/10.5194/egusphere-2025-5385, https://doi.org/10.5194/egusphere-2025-5385, 2025
Short summary
Short summary
Cyanobacteria form massive summer blooms in the Baltic Sea that release organic compounds to the ocean’s surface. By analyzing the thin boundary layer between ocean and atmosphere, this study shows that cyanobacteria influence the molecular composition and surface properties of the sea surface, increasing surfactants that may reduce gas exchange. The findings provide new insight into how future cyanobacteria blooms could affect air-sea interactions and climate-related processes.
Anisbel Leon-Marcos, Moritz Zeising, Manuela van Pinxteren, Sebastian Zeppenfeld, Astrid Bracher, Elena Barbaro, Anja Engel, Matteo Feltracco, Ina Tegen, and Bernd Heinold
Geosci. Model Dev., 18, 4183–4213, https://doi.org/10.5194/gmd-18-4183-2025, https://doi.org/10.5194/gmd-18-4183-2025, 2025
Short summary
Short summary
This study represents the primary marine organic aerosol (PMOA) emissions, focusing on their sea–atmosphere transfer. Using the FESOM2.1–REcoM3 model, concentrations of key organic biomolecules were estimated and integrated into the ECHAM6.3–HAM2.3 aerosol–climate model. Results highlight the influence of marine biological activity and surface winds on PMOA emissions, with reasonably good agreement with observations improving aerosol representation in the southern oceans.
Karine Sellegri, Theresa Barthelmeß, Jonathan Trueblood, Antonia Cristi, Evelyn Freney, Clémence Rose, Neill Barr, Mike Harvey, Karl Safi, Stacy Deppeler, Karen Thompson, Wayne Dillon, Anja Engel, and Cliff Law
Atmos. Chem. Phys., 23, 12949–12964, https://doi.org/10.5194/acp-23-12949-2023, https://doi.org/10.5194/acp-23-12949-2023, 2023
Short summary
Short summary
The amount of sea spray emitted to the atmosphere depends on the ocean temperature, but this dependency is not well understood, especially when ocean biology is involved. In this study, we show that sea spray emissions are increased by up to a factor of 4 at low seawater temperatures compared to moderate temperatures, and we quantify the temperature dependence as a function of the ocean biogeochemistry.
Manon Rocco, Erin Dunne, Alexia Saint-Macary, Maija Peltola, Theresa Barthelmeß, Neill Barr, Karl Safi, Andrew Marriner, Stacy Deppeler, James Harnwell, Anja Engel, Aurélie Colomb, Alfonso Saiz-Lopez, Mike Harvey, Cliff S. Law, and Karine Sellegri
EGUsphere, https://doi.org/10.5194/egusphere-2023-516, https://doi.org/10.5194/egusphere-2023-516, 2023
Preprint archived
Short summary
Short summary
During the Sea2cloud campaign in the Southern Pacific Ocean, we measured air-sea emissions from phytopankton of two key atmospheric compounds: DMS and MeSH. These compounds are well-known to play a great role in atmospheric chemistry and climate. We see in this paper that these compounds are most emited by the nanophytoplankton population. We provide here parameters for climate models to predict future trends of the emissions of these compounds and their roles and impacts on the global warming.
Lin Yang, Jing Zhang, Anja Engel, and Gui-Peng Yang
Biogeosciences, 19, 5251–5268, https://doi.org/10.5194/bg-19-5251-2022, https://doi.org/10.5194/bg-19-5251-2022, 2022
Short summary
Short summary
Enrichment factors of dissolved organic matter (DOM) in the eastern marginal seas of China exhibited a significant spatio-temporal variation. Photochemical and enrichment processes co-regulated DOM enrichment in the sea-surface microlayer (SML). Autochthonous DOM was more frequently enriched in the SML than terrestrial DOM. DOM in the sub-surface water exhibited higher aromaticity than that in the SML.
Quentin Devresse, Kevin W. Becker, Arne Bendinger, Johannes Hahn, and Anja Engel
Biogeosciences, 19, 5199–5219, https://doi.org/10.5194/bg-19-5199-2022, https://doi.org/10.5194/bg-19-5199-2022, 2022
Short summary
Short summary
Eddies are ubiquitous in the ocean and alter physical, chemical, and biological processes. However, how they affect organic carbon production and consumption is largely unknown. Here we show how an eddy triggers a cascade effect on biomass production and metabolic activities of phyto- and bacterioplankton. Our results may contribute to the improvement of biogeochemical models used to estimate carbon fluxes in the ocean.
Theresa Barthelmeß and Anja Engel
Biogeosciences, 19, 4965–4992, https://doi.org/10.5194/bg-19-4965-2022, https://doi.org/10.5194/bg-19-4965-2022, 2022
Short summary
Short summary
Greenhouse gases released by human activity cause a global rise in mean temperatures. While scientists can predict how much of these gases accumulate in the atmosphere based on not only human-derived sources but also oceanic sinks, it is rather difficult to predict the major influence of coastal ecosystems. We provide a detailed study on the occurrence, composition, and controls of substances that suppress gas exchange. We thus help to determine what controls coastal greenhouse gas fluxes.
Manuela van Pinxteren, Tiera-Brandy Robinson, Sebastian Zeppenfeld, Xianda Gong, Enno Bahlmann, Khanneh Wadinga Fomba, Nadja Triesch, Frank Stratmann, Oliver Wurl, Anja Engel, Heike Wex, and Hartmut Herrmann
Atmos. Chem. Phys., 22, 5725–5742, https://doi.org/10.5194/acp-22-5725-2022, https://doi.org/10.5194/acp-22-5725-2022, 2022
Short summary
Short summary
A class of marine particles (transparent exopolymer particles, TEPs) that is ubiquitously found in the world oceans was measured for the first time in ambient marine aerosol particles and marine cloud waters in the tropical Atlantic Ocean. TEPs are likely to have good properties for influencing clouds. We show that TEPs are transferred from the ocean to the marine atmosphere via sea-spray formation and our results suggest that they can also form directly in aerosol particles and in cloud water.
France Van Wambeke, Vincent Taillandier, Karine Desboeufs, Elvira Pulido-Villena, Julie Dinasquet, Anja Engel, Emilio Marañón, Céline Ridame, and Cécile Guieu
Biogeosciences, 18, 5699–5717, https://doi.org/10.5194/bg-18-5699-2021, https://doi.org/10.5194/bg-18-5699-2021, 2021
Short summary
Short summary
Simultaneous in situ measurements of (dry and wet) atmospheric deposition and biogeochemical stocks and fluxes in the sunlit waters of the open Mediterranean Sea revealed complex physical and biological processes occurring within the mixed layer. Nitrogen (N) budgets were computed to compare the sources and sinks of N in the mixed layer. The transitory effect observed after a wet dust deposition impacted the microbial food web down to the deep chlorophyll maximum.
Frédéric Gazeau, France Van Wambeke, Emilio Marañón, Maria Pérez-Lorenzo, Samir Alliouane, Christian Stolpe, Thierry Blasco, Nathalie Leblond, Birthe Zäncker, Anja Engel, Barbara Marie, Julie Dinasquet, and Cécile Guieu
Biogeosciences, 18, 5423–5446, https://doi.org/10.5194/bg-18-5423-2021, https://doi.org/10.5194/bg-18-5423-2021, 2021
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Our study shows that the impact of dust deposition on primary production depends on the initial composition and metabolic state of the tested community and is constrained by the amount of nutrients added, to sustain both the fast response of heterotrophic prokaryotes and the delayed one of phytoplankton. Under future environmental conditions, heterotrophic metabolism will be more impacted than primary production, therefore reducing the capacity of surface waters to sequester anthropogenic CO2.
Evelyn Freney, Karine Sellegri, Alessia Nicosia, Leah R. Williams, Matteo Rinaldi, Jonathan T. Trueblood, André S. H. Prévôt, Melilotus Thyssen, Gérald Grégori, Nils Haëntjens, Julie Dinasquet, Ingrid Obernosterer, France Van Wambeke, Anja Engel, Birthe Zäncker, Karine Desboeufs, Eija Asmi, Hilkka Timonen, and Cécile Guieu
Atmos. Chem. Phys., 21, 10625–10641, https://doi.org/10.5194/acp-21-10625-2021, https://doi.org/10.5194/acp-21-10625-2021, 2021
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In this work, we present observations of the organic aerosol content in primary sea spray aerosols (SSAs) continuously generated along a 5-week cruise in the Mediterranean. This information is combined with seawater biogeochemical properties also measured continuously along the ship track to develop a number of parametrizations that can be used in models to determine SSA organic content in oligotrophic waters that represent 60 % of the oceans from commonly measured seawater variables.
Gerd Krahmann, Damian L. Arévalo-Martínez, Andrew W. Dale, Marcus Dengler, Anja Engel, Nicolaas Glock, Patricia Grasse, Johannes Hahn, Helena Hauss, Mark Hopwood, Rainer Kiko, Alexandra Loginova, Carolin R. Löscher, Marie Maßmig, Alexandra-Sophie Roy, Renato Salvatteci, Stefan Sommer, Toste Tanhua, and Hela Mehrtens
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2020-308, https://doi.org/10.5194/essd-2020-308, 2021
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The project "Climate-Biogeochemistry Interactions in the Tropical Ocean" (SFB 754) was a multidisciplinary research project active from 2008 to 2019 aimed at a better understanding of the coupling between the tropical climate and ocean circulation and the ocean's oxygen and nutrient balance. On 34 research cruises, mainly in the Southeast Tropical Pacific and the Northeast Tropical Atlantic, 1071 physical, chemical and biological data sets were collected.
France Van Wambeke, Elvira Pulido, Philippe Catala, Julie Dinasquet, Kahina Djaoudi, Anja Engel, Marc Garel, Sophie Guasco, Barbara Marie, Sandra Nunige, Vincent Taillandier, Birthe Zäncker, and Christian Tamburini
Biogeosciences, 18, 2301–2323, https://doi.org/10.5194/bg-18-2301-2021, https://doi.org/10.5194/bg-18-2301-2021, 2021
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Michaelis–Menten kinetics were determined for alkaline phosphatase, aminopeptidase and β-glucosidase in the Mediterranean Sea. Although the ectoenzymatic-hydrolysis contribution to heterotrophic prokaryotic needs was high in terms of N, it was low in terms of C. This study points out the biases in interpretation of the relative differences in activities among the three tested enzymes in regard to the choice of added concentrations of fluorogenic substrates.
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Editorial statement
I am willing to support the recommendation by the associate editor to classify the manuscript as a highlight paper. Another reason for highlighting the mansucript is the fact that the study used natural seawater to mimic oceanic conditions. (The overwhelming majority of wind/wave tunnel studies uses freshwater.) Therefore, the results of the study by Engel et al. are unique because the study tried to come as close as possible to natural (i.e. oceanic) conditions.
I am willing to support the recommendation by the associate editor to classify the manuscript...
Short summary
We investigated how organic molecules in the ocean's surface layer accumulate and respond to wind. Using a large wind-wave tank filled with seawater, we found that natural molecules produced by marine microbes gather at the surface under light winds, slowing the exchange of gases such as carbon dioxide. When winds increase, this layer rapidly breaks down. These findings suggest that marine life can influence how the ocean and atmosphere interact, particularly in calm conditions.
We investigated how organic molecules in the ocean's surface layer accumulate and respond to...
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