Articles | Volume 15, issue 19
https://doi.org/10.5194/bg-15-5891-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-15-5891-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
05 Oct 2018
Research article |
| 05 Oct 2018
An intercomparison of oceanic methane and nitrous oxide measurements
University of Hawai'i at Manoa, Daniel K. Inouye Center for Microbial
Oceanography: Research and Education (C-MORE), Honolulu, Hawai'i, USA
Hermann W. Bange
GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker
Weg 20, 24105 Kiel, Germany
Damian L. Arévalo-Martínez
GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker
Weg 20, 24105 Kiel, Germany
Jonathan Barnes
Newcastle University, School of Natural and Environmental Sciences,
Newcastle upon Tyne, UK
Alberto V. Borges
Université de Liège, Unité d'Océanographie Chimique,
Liège, Belgium
Ian Brown
Plymouth Marine Laboratory, Plymouth, UK
John L. Bullister
National Oceanic and Atmospheric Administration, Pacific Marine
Environmental Laboratory, Seattle, Washington, USA
Macarena Burgos
University of Hawai'i at Manoa, Daniel K. Inouye Center for Microbial
Oceanography: Research and Education (C-MORE), Honolulu, Hawai'i, USA
Universidad de Cádiz, Instituto de Investigaciones Marinas, Departmento Química-Física, Cádiz, Spain
David W. Capelle
University of British Columbia, Department of Earth, Ocean and Atmospheric Sciences, British Columbia, Vancouver, Canada
Michael Casso
U.S. Geological Survey, Woods Hole Coastal and Marine Science Center,
Woods Hole, USA
Mercedes de la Paz
Instituto de Investigaciones Marinas, Vigo, Spain
current address: Instituto Español de Oceanografía,
Centro Oceanográfico de A Coruña, A Coruña, Spain
Laura Farías
University of Concepción, Department of Oceanography and Center
for climate research and resilience (CR2), Concepción, Chile
Lindsay Fenwick
University of British Columbia, Department of Earth, Ocean and Atmospheric Sciences, British Columbia, Vancouver, Canada
Sara Ferrón
University of Hawai'i at Manoa, Daniel K. Inouye Center for Microbial
Oceanography: Research and Education (C-MORE), Honolulu, Hawai'i, USA
Gerardo Garcia
University of Concepción, Department of Oceanography and Center
for climate research and resilience (CR2), Concepción, Chile
Michael Glockzin
Leibniz Institute for Baltic Sea Research Warnemünde, Rostock,
Germany
David M. Karl
University of Hawai'i at Manoa, Daniel K. Inouye Center for Microbial
Oceanography: Research and Education (C-MORE), Honolulu, Hawai'i, USA
Annette Kock
GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker
Weg 20, 24105 Kiel, Germany
Sarah Laperriere
University of California Santa Barbara, Department of Ecology,
Evolution, and Marine Biology, Santa Barbara, USA
Cliff S. Law
National Institute of Water and Atmospheric Research (NIWA),
Wellington, New Zealand
Department of Chemistry, University of Otago, Dunedin, New
Zealand
Cara C. Manning
University of British Columbia, Department of Earth, Ocean and Atmospheric Sciences, British Columbia, Vancouver, Canada
Andrew Marriner
National Institute of Water and Atmospheric Research (NIWA),
Wellington, New Zealand
Jukka-Pekka Myllykangas
University of Helsinki, Department of Environmental Sciences,
Helsinki, Finland
John W. Pohlman
U.S. Geological Survey, Woods Hole Coastal and Marine Science Center,
Woods Hole, USA
Andrew P. Rees
Plymouth Marine Laboratory, Plymouth, UK
Alyson E. Santoro
University of California Santa Barbara, Department of Ecology,
Evolution, and Marine Biology, Santa Barbara, USA
Philippe D. Tortell
University of British Columbia, Department of Earth, Ocean and Atmospheric Sciences, British Columbia, Vancouver, Canada
Robert C. Upstill-Goddard
Newcastle University, School of Natural and Environmental Sciences,
Newcastle upon Tyne, UK
David P. Wisegarver
National Oceanic and Atmospheric Administration, Pacific Marine
Environmental Laboratory, Seattle, Washington, USA
Gui-Ling Zhang
University of China, Key Laboratory of Marine Chemistry Theory and Technology (MOE), Qingdao, China
Gregor Rehder
Leibniz Institute for Baltic Sea Research Warnemünde, Rostock,
Germany
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To understand how dimethyl sulfide (DMS) enrichment is maintained in the sea surface microlayer (SML) while DMS is lost to the atmosphere, deck-board incubation was carried out to determine DMS sources and sinks. Our results showed that the phytoplankton composition played an essential role in DMS processes in the SML. However, all accumulated DMS processes were lower than the calculated air–sea DMS flux.
Pierre Friedlingstein, Matthew W. Jones, Michael O'Sullivan, Robbie M. Andrew, Dorothee C. E. Bakker, Judith Hauck, Corinne Le Quéré, Glen P. Peters, Wouter Peters, Julia Pongratz, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Rob B. Jackson, Simone R. Alin, Peter Anthoni, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Laurent Bopp, Thi Tuyet Trang Chau, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Kim I. Currie, Bertrand Decharme, Laique M. Djeutchouang, Xinyu Dou, Wiley Evans, Richard A. Feely, Liang Feng, Thomas Gasser, Dennis Gilfillan, Thanos Gkritzalis, Giacomo Grassi, Luke Gregor, Nicolas Gruber, Özgür Gürses, Ian Harris, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Ingrid T. Luijkx, Atul Jain, Steve D. Jones, Etsushi Kato, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Arne Körtzinger, Peter Landschützer, Siv K. Lauvset, Nathalie Lefèvre, Sebastian Lienert, Junjie Liu, Gregg Marland, Patrick C. McGuire, Joe R. Melton, David R. Munro, Julia E. M. S. Nabel, Shin-Ichiro Nakaoka, Yosuke Niwa, Tsuneo Ono, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Thais M. Rosan, Jörg Schwinger, Clemens Schwingshackl, Roland Séférian, Adrienne J. Sutton, Colm Sweeney, Toste Tanhua, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Francesco Tubiello, Guido R. van der Werf, Nicolas Vuichard, Chisato Wada, Rik Wanninkhof, Andrew J. Watson, David Willis, Andrew J. Wiltshire, Wenping Yuan, Chao Yue, Xu Yue, Sönke Zaehle, and Jiye Zeng
Earth Syst. Sci. Data, 14, 1917–2005, https://doi.org/10.5194/essd-14-1917-2022, https://doi.org/10.5194/essd-14-1917-2022, 2022
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The Global Carbon Budget 2021 describes the data sets and methodology used to quantify the emissions of carbon dioxide and their partitioning among the atmosphere, land, and ocean. These living data are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Karol Kuliński, Gregor Rehder, Eero Asmala, Alena Bartosova, Jacob Carstensen, Bo Gustafsson, Per O. J. Hall, Christoph Humborg, Tom Jilbert, Klaus Jürgens, H. E. Markus Meier, Bärbel Müller-Karulis, Michael Naumann, Jørgen E. Olesen, Oleg Savchuk, Andreas Schramm, Caroline P. Slomp, Mikhail Sofiev, Anna Sobek, Beata Szymczycha, and Emma Undeman
Earth Syst. Dynam., 13, 633–685, https://doi.org/10.5194/esd-13-633-2022, https://doi.org/10.5194/esd-13-633-2022, 2022
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The paper covers the aspects related to changes in carbon, nitrogen, and phosphorus (C, N, P) external loads; their transformations in the coastal zone; changes in organic matter production (eutrophication) and remineralization (oxygen availability); and the role of sediments in burial and turnover of C, N, and P. Furthermore, this paper also focuses on changes in the marine CO2 system, the structure of the microbial community, and the role of contaminants for biogeochemical processes.
Brandon J. McNabb and Philippe D. Tortell
Biogeosciences, 19, 1705–1721, https://doi.org/10.5194/bg-19-1705-2022, https://doi.org/10.5194/bg-19-1705-2022, 2022
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The trace gas dimethyl sulfide (DMS) plays an important role in the ocean sulfur cycle and can also influence Earth’s climate. Our study used two statistical methods to predict surface ocean concentrations and rates of sea–air exchange of DMS in the northeast subarctic Pacific. Our results show improved predictive power over previous approaches and suggest that nutrient availability, light-dependent processes, and physical mixing may be important controls on DMS in this region.
Richard P. Sims, Michael Bedington, Ute Schuster, Andrew J. Watson, Vassilis Kitidis, Ricardo Torres, Helen S. Findlay, James R. Fishwick, Ian Brown, and Thomas G. Bell
Biogeosciences, 19, 1657–1674, https://doi.org/10.5194/bg-19-1657-2022, https://doi.org/10.5194/bg-19-1657-2022, 2022
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The amount of carbon dioxide (CO2) being absorbed by the ocean is relevant to the earth's climate. CO2 values in the coastal ocean and estuaries are not well known because of the instrumentation used. We used a new approach to measure CO2 across the coastal and estuarine zone. We found that CO2 and salinity were linked to the state of the tide. We used our CO2 measurements and model salinity to predict CO2. Previous studies overestimate how much CO2 the coastal ocean draws down at our site.
Darren R. Clark, Andrew P. Rees, Charissa M. Ferrera, Lisa Al-Moosawi, Paul J. Somerfield, Carolyn Harris, Graham D. Quartly, Stephen Goult, Glen Tarran, and Gennadi Lessin
Biogeosciences, 19, 1355–1376, https://doi.org/10.5194/bg-19-1355-2022, https://doi.org/10.5194/bg-19-1355-2022, 2022
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Measurements of microbial processes were made in the sunlit open ocean during a research cruise (AMT19) between the UK and Chile. These help us to understand how microbial communities maintain the function of remote ecosystems. We find that the nitrogen cycling microbes which produce nitrite respond to changes in the environment. Our insights will aid the development of models that aim to replicate and ultimately project how marine environments may respond to ongoing climate change.
Yanan Zhao, Dennis Booge, Christa A. Marandino, Cathleen Schlundt, Astrid Bracher, Elliot L. Atlas, Jonathan Williams, and Hermann W. Bange
Biogeosciences, 19, 701–714, https://doi.org/10.5194/bg-19-701-2022, https://doi.org/10.5194/bg-19-701-2022, 2022
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We present here, for the first time, simultaneously measured dimethylsulfide (DMS) seawater concentrations and DMS atmospheric mole fractions from the Peruvian upwelling region during two cruises in December 2012 and October 2015. Our results indicate low oceanic DMS concentrations and atmospheric DMS molar fractions in surface waters and the atmosphere, respectively. In addition, the Peruvian upwelling region was identified as an insignificant source of DMS emissions during both periods.
Jesse M. Vance, Kim Currie, John Zeldis, Peter W. Dillingham, and Cliff S. Law
Biogeosciences, 19, 241–269, https://doi.org/10.5194/bg-19-241-2022, https://doi.org/10.5194/bg-19-241-2022, 2022
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Long-term monitoring is needed to detect changes in our environment. Time series of ocean carbon have aided our understanding of seasonal cycles and provided evidence for ocean acidification. Data gaps are inevitable, yet no standard method for filling gaps exists. We present a regression approach here and compare it to seven other common methods to understand the impact of different approaches when assessing seasonal to climatic variability in ocean carbon.
Wangwang Ye, Hermann W. Bange, Damian L. Arévalo-Martínez, Hailun He, Yuhong Li, Jianwen Wen, Jiexia Zhang, Jian Liu, Man Wu, and Liyang Zhan
Biogeosciences Discuss., https://doi.org/10.5194/bg-2021-334, https://doi.org/10.5194/bg-2021-334, 2022
Manuscript not accepted for further review
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CH4 is the second important greenhouse gas after CO2. We show that CH4 consumption and sea-ice melting influence the CH4 distribution in the Ross Sea (Southern Ocean), causing undersaturation and net uptake of CH4 during summertime. This study confirms the capability of surface water in the high-latitude Southern Ocean regions to take up atmospheric CH4 which, in turn, will help to improve predictions of how CH4 release/uptake from the ocean will develop when sea-ice retreats in the future.
Martti Honkanen, Jens Daniel Müller, Jukka Seppälä, Gregor Rehder, Sami Kielosto, Pasi Ylöstalo, Timo Mäkelä, Juha Hatakka, and Lauri Laakso
Ocean Sci., 17, 1657–1675, https://doi.org/10.5194/os-17-1657-2021, https://doi.org/10.5194/os-17-1657-2021, 2021
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The exchange of carbon dioxide (CO2) between the sea and the atmosphere is regulated by the gradient of CO2 partial pressure (pCO2) between the sea and the air. The daily variation of the seawater pCO2 recorded at the fixed station Utö in the Baltic Sea was found to be mainly biologically driven. Calculation of the annual net exchange of CO2 between the sea and atmosphere based on daily measurements of pCO2 carried out using the same sampling time every day could introduce a bias of up to 12 %.
Kun Jia, Cara C. M. Manning, Ashlee Jollymore, and Roger D. Beckie
Hydrol. Earth Syst. Sci., 25, 4983–4993, https://doi.org/10.5194/hess-25-4983-2021, https://doi.org/10.5194/hess-25-4983-2021, 2021
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The effect of soluble reduced iron, Fe(II), on fluorescence data (excitation–emission matrix spectra parsed using parallel factor analysis) is difficult to quantitatively assign. We added varying quantities of Fe(II) into groundwater from an anaerobic aquifer. We showed that the overall fluorescence intensity decreased nonlinearly as Fe(II) increased from 1 to 306 mg L-1 but that the parallel factor analysis component distribution was relatively insensitive to Fe(II) concentration.
Jens Daniel Müller, Bernd Schneider, Ulf Gräwe, Peer Fietzek, Marcus Bo Wallin, Anna Rutgersson, Norbert Wasmund, Siegfried Krüger, and Gregor Rehder
Biogeosciences, 18, 4889–4917, https://doi.org/10.5194/bg-18-4889-2021, https://doi.org/10.5194/bg-18-4889-2021, 2021
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Based on profiling pCO2 measurements from a field campaign, we quantify the biomass production of a cyanobacteria bloom in the Baltic Sea, the export of which would foster deep water deoxygenation. We further demonstrate how this biomass production can be accurately reconstructed from long-term surface measurements made on cargo vessels in combination with modelled temperature profiles. This approach enables a better understanding of a severe concern for the Baltic’s good environmental status.
Stefanie Kremser, Mike Harvey, Peter Kuma, Sean Hartery, Alexia Saint-Macary, John McGregor, Alex Schuddeboom, Marc von Hobe, Sinikka T. Lennartz, Alex Geddes, Richard Querel, Adrian McDonald, Maija Peltola, Karine Sellegri, Israel Silber, Cliff S. Law, Connor J. Flynn, Andrew Marriner, Thomas C. J. Hill, Paul J. DeMott, Carson C. Hume, Graeme Plank, Geoffrey Graham, and Simon Parsons
Earth Syst. Sci. Data, 13, 3115–3153, https://doi.org/10.5194/essd-13-3115-2021, https://doi.org/10.5194/essd-13-3115-2021, 2021
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Aerosol–cloud interactions over the Southern Ocean are poorly understood and remain a major source of uncertainty in climate models. This study presents ship-borne measurements, collected during a 6-week voyage into the Southern Ocean in 2018, that are an important supplement to satellite-based measurements. For example, these measurements include data on low-level clouds and aerosol composition in the marine boundary layer, which can be used in climate model evaluation efforts.
Erik Jacobs, Henry C. Bittig, Ulf Gräwe, Carolyn A. Graves, Michael Glockzin, Jens D. Müller, Bernd Schneider, and Gregor Rehder
Biogeosciences, 18, 2679–2709, https://doi.org/10.5194/bg-18-2679-2021, https://doi.org/10.5194/bg-18-2679-2021, 2021
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We use a unique data set of 8 years of continuous carbon dioxide (CO2) and methane (CH4) surface water measurements from a commercial ferry to study upwelling in the Baltic Sea. Its seasonality and regional and interannual variability are examined. Strong upwelling events drastically increase local surface CO2 and CH4 levels and are mostly detected in late summer after long periods of impaired mixing. We introduce an extrapolation method to estimate regional upwelling-induced trace gas fluxes.
Trystan Sanders, Jörn Thomsen, Jens Daniel Müller, Gregor Rehder, and Frank Melzner
Biogeosciences, 18, 2573–2590, https://doi.org/10.5194/bg-18-2573-2021, https://doi.org/10.5194/bg-18-2573-2021, 2021
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The Baltic Sea is expected to experience a rapid drop in salinity and increases in acidity and warming in the next century. Calcifying mussels dominate Baltic Sea seafloor ecosystems yet are sensitive to changes in seawater chemistry. We combine laboratory experiments and a field study and show that a lack of calcium causes extremely slow growth rates in mussels at low salinities. Subsequently, climate change in the Baltic may have drastic ramifications for Baltic seafloor ecosystems.
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
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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.
Yanan Zhao, Cathleen Schlundt, Dennis Booge, and Hermann W. Bange
Biogeosciences, 18, 2161–2179, https://doi.org/10.5194/bg-18-2161-2021, https://doi.org/10.5194/bg-18-2161-2021, 2021
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We present a unique and comprehensive time-series study of biogenic sulfur compounds in the southwestern Baltic Sea, from 2009 to 2018. Dimethyl sulfide is one of the key players regulating global climate change, as well as dimethylsulfoniopropionate and dimethyl sulfoxide. Their decadal trends did not follow increasing temperature but followed some algae group abundances at the Boknis Eck Time Series Station.
Anna Rose Canning, Peer Fietzek, Gregor Rehder, and Arne Körtzinger
Biogeosciences, 18, 1351–1373, https://doi.org/10.5194/bg-18-1351-2021, https://doi.org/10.5194/bg-18-1351-2021, 2021
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The paper describes a novel, fully autonomous, multi-gas flow-through set-up for multiple gases that combines established, high-quality oceanographic sensors in a small and robust system designed for use across all salinities and all types of platforms. We describe the system and its performance in all relevant detail, including the corrections which improve the accuracy of these sensors, and illustrate how simultaneous multi-gas set-ups can provide an extremely high spatiotemporal resolution.
Meike Becker, Are Olsen, Peter Landschützer, Abdirhaman Omar, Gregor Rehder, Christian Rödenbeck, and Ingunn Skjelvan
Biogeosciences, 18, 1127–1147, https://doi.org/10.5194/bg-18-1127-2021, https://doi.org/10.5194/bg-18-1127-2021, 2021
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We developed a simple method to refine existing open-ocean maps towards different coastal seas. Using a multi-linear regression, we produced monthly maps of surface ocean fCO2 in the northern European coastal seas (the North Sea, the Baltic Sea, the Norwegian Coast and the Barents Sea) covering a time period from 1998 to 2016. Based on this fCO2 map, we calculate trends in surface ocean fCO2, pH and the air–sea gas exchange.
Chuan Qin, Guiling Zhang, Wenjing Zheng, Yu Han, and Sumei Liu
Ocean Sci., 17, 249–264, https://doi.org/10.5194/os-17-249-2021, https://doi.org/10.5194/os-17-249-2021, 2021
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We conducted an underway measurement of dissolved O2 / Ar using membrane inlet mass spectrometry and estimated net community production (NCP) in the South China Sea (SCS) in both summer and autumn. We found that nutrient content, especially nitrogen, is the dominant factor affecting primary production in the SCS. In the summer, we observed a rapid response of the ecosystem to episodic nutrient supply induced by eddies. This is the first report on NCP estimation based on O2 / Ar data in the SCS.
Samuel T. Wilson, Alia N. Al-Haj, Annie Bourbonnais, Claudia Frey, Robinson W. Fulweiler, John D. Kessler, Hannah K. Marchant, Jana Milucka, Nicholas E. Ray, Parvadha Suntharalingam, Brett F. Thornton, Robert C. Upstill-Goddard, Thomas S. Weber, Damian L. Arévalo-Martínez, Hermann W. Bange, Heather M. Benway, Daniele Bianchi, Alberto V. Borges, Bonnie X. Chang, Patrick M. Crill, Daniela A. del Valle, Laura Farías, Samantha B. Joye, Annette Kock, Jabrane Labidi, Cara C. Manning, John W. Pohlman, Gregor Rehder, Katy J. Sparrow, Philippe D. Tortell, Tina Treude, David L. Valentine, Bess B. Ward, Simon Yang, and Leonid N. Yurganov
Biogeosciences, 17, 5809–5828, https://doi.org/10.5194/bg-17-5809-2020, https://doi.org/10.5194/bg-17-5809-2020, 2020
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The oceans are a net source of the major greenhouse gases; however there has been little coordination of oceanic methane and nitrous oxide measurements. The scientific community has recently embarked on a series of capacity-building exercises to improve the interoperability of dissolved methane and nitrous oxide measurements. This paper derives from a workshop which discussed the challenges and opportunities for oceanic methane and nitrous oxide research in the near future.
Cédric Morana, Steven Bouillon, Vimac Nolla-Ardèvol, Fleur A. E. Roland, William Okello, Jean-Pierre Descy, Angela Nankabirwa, Erina Nabafu, Dirk Springael, and Alberto V. Borges
Biogeosciences, 17, 5209–5221, https://doi.org/10.5194/bg-17-5209-2020, https://doi.org/10.5194/bg-17-5209-2020, 2020
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A growing body of studies challenges the paradigm that methane (CH4) production occurs only under anaerobic conditions. Our field experiments revealed that oxic CH4 production is closely related to phytoplankton metabolism and is indeed a common feature in five contrasting African lakes. Nevertheless, we found that methanotrophic activity in surface waters and CH4 emissions to the atmosphere were predominantly fuelled by CH4 generated in sediments and physically transported to the surface.
Luke T. Cravigan, Marc D. Mallet, Petri Vaattovaara, Mike J. Harvey, Cliff S. Law, Robin L. Modini, Lynn M. Russell, Ed Stelcer, David D. Cohen, Greg Olsen, Karl Safi, Timothy J. Burrell, and Zoran Ristovski
Atmos. Chem. Phys., 20, 7955–7977, https://doi.org/10.5194/acp-20-7955-2020, https://doi.org/10.5194/acp-20-7955-2020, 2020
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Aerosol–cloud interactions in remote marine environments are poorly represented in atmospheric modelling, particularly over the Southern Hemisphere. This work reports in situ chamber observations of sea spray aerosol composition and water uptake during the Surface Ocean Aerosol Production (SOAP) voyage. Observations were compared with currently applied models for sea spray organic enrichment. The sea spray hygroscopicity was persistently high, even at high organic fractions.
Xiao Ma, Mingshuang Sun, Sinikka T. Lennartz, and Hermann W. Bange
Biogeosciences, 17, 3427–3438, https://doi.org/10.5194/bg-17-3427-2020, https://doi.org/10.5194/bg-17-3427-2020, 2020
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Monthly measurements of dissolved methane (CH4), a potent greenhouse gas, were conducted at Boknis Eck (BE), a time-series station in the southwestern Baltic Sea, from June 2006. In general CH4 concentrations increased with depth. High concentrations in the upper layer were linked to saline water inflow. Eckernförde Bay emitted CH4 to the atmosphere throughout the monitoring period. No significant trend was detected in CH4 concentrations or emissions during 2006–2017.
Sarah Z. Rosengard, Robert W. Izett, William J. Burt, Nina Schuback, and Philippe D. Tortell
Biogeosciences, 17, 3277–3298, https://doi.org/10.5194/bg-17-3277-2020, https://doi.org/10.5194/bg-17-3277-2020, 2020
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Net community production sets the maximum quantity of phytoplankton carbon available for the marine food web and longer-term storage in the deep ocean. We compared two approaches to estimate this critical variable from autonomous measurements of mixed-layer dissolved oxygen and particulate organic carbon, observing a significant discrepancy between estimates in an upwelling zone near the Oregon coast. We use this discrepancy to assess the fate of organic carbon produced in the mixed layer.
Claudia Frey, Hermann W. Bange, Eric P. Achterberg, Amal Jayakumar, Carolin R. Löscher, Damian L. Arévalo-Martínez, Elizabeth León-Palmero, Mingshuang Sun, Xin Sun, Ruifang C. Xie, Sergey Oleynik, and Bess B. Ward
Biogeosciences, 17, 2263–2287, https://doi.org/10.5194/bg-17-2263-2020, https://doi.org/10.5194/bg-17-2263-2020, 2020
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The production of N2O via nitrification and denitrification associated with low-O2 waters is a major source of oceanic N2O. We investigated the regulation and dynamics of these processes with respect to O2 and organic matter inputs. The transcription of the key nitrification gene amoA rapidly responded to changes in O2 and strongly correlated with N2O production rates. N2O production by denitrification was clearly stimulated by organic carbon, implying that its supply controls N2O production.
Sinikka T. Lennartz, Christa A. Marandino, Marc von Hobe, Meinrat O. Andreae, Kazushi Aranami, Elliot Atlas, Max Berkelhammer, Heinz Bingemer, Dennis Booge, Gregory Cutter, Pau Cortes, Stefanie Kremser, Cliff S. Law, Andrew Marriner, Rafel Simó, Birgit Quack, Günther Uher, Huixiang Xie, and Xiaobin Xu
Earth Syst. Sci. Data, 12, 591–609, https://doi.org/10.5194/essd-12-591-2020, https://doi.org/10.5194/essd-12-591-2020, 2020
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Sulfur-containing trace gases in the atmosphere influence atmospheric chemistry and the energy budget of the Earth by forming aerosols. The ocean is an important source of the most abundant sulfur gas in the atmosphere, carbonyl sulfide (OCS) and its most important precursor carbon disulfide (CS2). In order to assess global variability of the sea surface concentrations of both gases to calculate their oceanic emissions, we have compiled a database of existing shipborne measurements.
Sarah J. Lawson, Cliff S. Law, Mike J. Harvey, Thomas G. Bell, Carolyn F. Walker, Warren J. de Bruyn, and Eric S. Saltzman
Atmos. Chem. Phys., 20, 3061–3078, https://doi.org/10.5194/acp-20-3061-2020, https://doi.org/10.5194/acp-20-3061-2020, 2020
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Methanethiol (MeSH) is a reduced sulfur gas originating from phytoplankton, with a global ocean source of ~ 17 % of dimethyl sulfide (DMS). It has been little studied and is rarely observed over the ocean. In this work, MeSH was measured at much higher levels than previously observed (3–36 % of parallel DMS mixing ratios). MeSH could be a significant source of atmospheric sulfur over productive regions of the ocean, but its distribution, and its atmospheric impact, requires more investigation.
Carolin R. Löscher, Wiebke Mohr, Hermann W. Bange, and Donald E. Canfield
Biogeosciences, 17, 851–864, https://doi.org/10.5194/bg-17-851-2020, https://doi.org/10.5194/bg-17-851-2020, 2020
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Oxygen minimum zones (OMZs) are ocean areas severely depleted in oxygen as a result of physical, chemical, and biological processes. Biologically, organic material is produced in the sea surface and exported to deeper waters, where it respires. In the Bay of Bengal (BoB), an OMZ is present, but there are traces of oxygen left. Our study now suggests that this is because one key process, nitrogen fixation, is absent in the BoB, thus preventing primary production and consecutive respiration.
Ye Tian, Gui-Peng Yang, Chun-Ying Liu, Pei-Feng Li, Hong-Tao Chen, and Hermann W. Bange
Ocean Sci., 16, 135–148, https://doi.org/10.5194/os-16-135-2020, https://doi.org/10.5194/os-16-135-2020, 2020
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Nitric oxide (NO) could be produced by nitrite photolysis; the rates from dissolved nitrite in artificial seawater showed increasing trends with decreasing pH, increasing temperatures, and increasing salinity. However, NO photoproduction from the natural seawater samples did not show correlations with pH, water temperature, salinity, or dissolved nitrite concentrations in the western tropical North Pacific Ocean (WNTP). And there were other NO loss processes in the surface layer of WNTP.
Thomas Holding, Ian G. Ashton, Jamie D. Shutler, Peter E. Land, Philip D. Nightingale, Andrew P. Rees, Ian Brown, Jean-Francois Piolle, Annette Kock, Hermann W. Bange, David K. Woolf, Lonneke Goddijn-Murphy, Ryan Pereira, Frederic Paul, Fanny Girard-Ardhuin, Bertrand Chapron, Gregor Rehder, Fabrice Ardhuin, and Craig J. Donlon
Ocean Sci., 15, 1707–1728, https://doi.org/10.5194/os-15-1707-2019, https://doi.org/10.5194/os-15-1707-2019, 2019
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FluxEngine is an open-source software toolbox designed to allow for the easy and accurate calculation of air–sea gas fluxes. This article describes new functionality and capabilities, which include the ability to calculate fluxes for nitrous oxide and methane, optimisation for running FluxEngine on a stand-alone desktop computer, and extensive new features to support the in situ measurement community. Four research case studies are used to demonstrate these new features.
Pierre Friedlingstein, Matthew W. Jones, Michael O'Sullivan, Robbie M. Andrew, Judith Hauck, Glen P. Peters, Wouter Peters, Julia Pongratz, Stephen Sitch, Corinne Le Quéré, Dorothee C. E. Bakker, Josep G. Canadell, Philippe Ciais, Robert B. Jackson, Peter Anthoni, Leticia Barbero, Ana Bastos, Vladislav Bastrikov, Meike Becker, Laurent Bopp, Erik Buitenhuis, Naveen Chandra, Frédéric Chevallier, Louise P. Chini, Kim I. Currie, Richard A. Feely, Marion Gehlen, Dennis Gilfillan, Thanos Gkritzalis, Daniel S. Goll, Nicolas Gruber, Sören Gutekunst, Ian Harris, Vanessa Haverd, Richard A. Houghton, George Hurtt, Tatiana Ilyina, Atul K. Jain, Emilie Joetzjer, Jed O. Kaplan, Etsushi Kato, Kees Klein Goldewijk, Jan Ivar Korsbakken, Peter Landschützer, Siv K. Lauvset, Nathalie Lefèvre, Andrew Lenton, Sebastian Lienert, Danica Lombardozzi, Gregg Marland, Patrick C. McGuire, Joe R. Melton, Nicolas Metzl, David R. Munro, Julia E. M. S. Nabel, Shin-Ichiro Nakaoka, Craig Neill, Abdirahman M. Omar, Tsuneo Ono, Anna Peregon, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Roland Séférian, Jörg Schwinger, Naomi Smith, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Francesco N. Tubiello, Guido R. van der Werf, Andrew J. Wiltshire, and Sönke Zaehle
Earth Syst. Sci. Data, 11, 1783–1838, https://doi.org/10.5194/essd-11-1783-2019, https://doi.org/10.5194/essd-11-1783-2019, 2019
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The Global Carbon Budget 2019 describes the data sets and methodology used to quantify the emissions of carbon dioxide and their partitioning among the atmosphere, land, and ocean. These living data are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Ye Tian, Chao Xue, Chun-Ying Liu, Gui-Peng Yang, Pei-Feng Li, Wei-Hua Feng, and Hermann W. Bange
Biogeosciences, 16, 4485–4496, https://doi.org/10.5194/bg-16-4485-2019, https://doi.org/10.5194/bg-16-4485-2019, 2019
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Nitric oxide (NO) seems to be widespread, with different functions in the marine ecosystem, but we know little about it. Concentrations of NO were in a range from below the limit of detection to 616 pmol L−1 at the surface and 482 pmol L−1 at the bottom of the Bohai and Yellow seas. The study region was a source of atmospheric NO. Net NO sea-to-air fluxes were much lower than NO photoproduction rates, implying that the NO produced in the mixed layer was rapidly consumed before entering the air.
Hermann W. Bange, Chun Hock Sim, Daniel Bastian, Jennifer Kallert, Annette Kock, Aazani Mujahid, and Moritz Müller
Biogeosciences, 16, 4321–4335, https://doi.org/10.5194/bg-16-4321-2019, https://doi.org/10.5194/bg-16-4321-2019, 2019
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Nitrous oxide (N2O) and methane (CH4) are atmospheric trace gases which play important roles in the climate and atmospheric chemistry of the Earth. However, little is known about their emissions from rivers and estuaries. To this end, concentrations of N2O and CH4 were measured during a seasonal study in six rivers and estuaries in northwestern Borneo. The concentrations of both gases were mainly driven by rainfall. The rivers and estuaries were an overall net source of atmospheric N2O and CH4.
Xiao Ma, Sinikka T. Lennartz, and Hermann W. Bange
Biogeosciences, 16, 4097–4111, https://doi.org/10.5194/bg-16-4097-2019, https://doi.org/10.5194/bg-16-4097-2019, 2019
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Monthly measurements of nitrous oxide (N2O), a potent greenhouse gas and ozone depletion agent, were conducted at Boknis Eck (BE), a time series station in the southwestern Baltic Sea, since July 2005. Low N2O concentrations were observed in autumn and high in winter and early spring. Dissolved nutrients and oxygen played important roles in N2O distribution. Although we did not observe a significant N2O trend during 2005–2017, a decrease in N2O concentration and emission seems likely in future.
Eric J. Morgan, Jost V. Lavric, Damian L. Arévalo-Martínez, Hermann W. Bange, Tobias Steinhoff, Thomas Seifert, and Martin Heimann
Biogeosciences, 16, 4065–4084, https://doi.org/10.5194/bg-16-4065-2019, https://doi.org/10.5194/bg-16-4065-2019, 2019
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Taking a 2-year atmospheric record of atmospheric oxygen and the greenhouse gases N2O, CO2, and CH4, made at a coastal site in the Namib Desert, we estimated the fluxes of these gases from upwelling events in the northern Benguela Current region. We compared these results with flux measurements made on a research vessel in the study area at the same time and found that the two approaches agreed well. The study region was a source of N2O, CO2, and CH4 to the atmosphere during upwelling events.
Alberto V. Borges, François Darchambeau, Thibault Lambert, Cédric Morana, George H. Allen, Ernest Tambwe, Alfred Toengaho Sembaito, Taylor Mambo, José Nlandu Wabakhangazi, Jean-Pierre Descy, Cristian R. Teodoru, and Steven Bouillon
Biogeosciences, 16, 3801–3834, https://doi.org/10.5194/bg-16-3801-2019, https://doi.org/10.5194/bg-16-3801-2019, 2019
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Tropical rivers might be strong sources of CO2 and CH4 to the atmosphere, although there is an enormous data gap. The origin of CO2 in lowland tropical rivers is not well characterized and can be from terra firme or from wetlands (flooded forests and aquatic macrophytes). We obtained a large field dataset of CO2, CH4 and N2O in the Congo, the second-largest river in the world, which allows us to quantity the emission of these greenhouse gases to the atmosphere and investigate their origin.
Cara C. Manning, Rachel H. R. Stanley, David P. Nicholson, Brice Loose, Ann Lovely, Peter Schlosser, and Bruce G. Hatcher
Biogeosciences, 16, 3351–3376, https://doi.org/10.5194/bg-16-3351-2019, https://doi.org/10.5194/bg-16-3351-2019, 2019
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We measured rates of biological activity and gas exchange in a Canadian estuary during ice melt. We quantified gas exchange using inert, deliberately released tracers and found that the gas transfer rate at > 90 % ice cover was 6 % of the rate for nearly ice-free conditions. We measured oxygen concentration and isotopic composition and used the data to detect changes in the rates of photosynthesis and respiration (autotrophy and heterotrophy) as the ice melted.
Tim Fischer, Annette Kock, Damian L. Arévalo-Martínez, Marcus Dengler, Peter Brandt, and Hermann W. Bange
Biogeosciences, 16, 2307–2328, https://doi.org/10.5194/bg-16-2307-2019, https://doi.org/10.5194/bg-16-2307-2019, 2019
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We investigated air–sea gas exchange in oceanic upwelling regions for the case of nitrous oxide off Peru. In this region, routine concentration measurements from ships at 5 m or 10 m depth prove to overestimate surface (bulk) concentration. Thus, standard estimates of gas exchange will show systematic error. This is due to very shallow stratified layers that inhibit exchange between surface water and waters below and can exist for several days. Maximum bias occurs in moderate wind conditions.
Qixing Ji, Mark A. Altabet, Hermann W. Bange, Michelle I. Graco, Xiao Ma, Damian L. Arévalo-Martínez, and Damian S. Grundle
Biogeosciences, 16, 2079–2093, https://doi.org/10.5194/bg-16-2079-2019, https://doi.org/10.5194/bg-16-2079-2019, 2019
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A strong El Niño event occurred in the Peruvian coastal region in 2015–2016, during which higher sea surface temperatures co-occurred with significantly lower sea-to-air fluxes of nitrous oxide, an important greenhouse gas and ozone depletion agent. Stratified water column during El Niño retained a larger amount of nitrous oxide that was produced via multiple microbial pathways; and intense nitrous oxide effluxes could occur when normal upwelling is resumed after El Niño.
Alysia E. Herr, Ronald P. Kiene, John W. H. Dacey, and Philippe D. Tortell
Biogeosciences, 16, 1729–1754, https://doi.org/10.5194/bg-16-1729-2019, https://doi.org/10.5194/bg-16-1729-2019, 2019
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Dimethylsulfide (DMS) is an essential component of the global sulfur cycle and a major source of climate-influencing aerosols. We examine the drivers of DMS concentration gradients along the British Columbia shelf by comparing DMS measurements to environmental variables and biological rates. We further combine new and existing data sets to provide a new summertime DMS climatology for the northeast subarctic Pacific. Our results highlight the importance of phytoplankton taxonomy to DMS cycling.
Nina Schuback and Philippe D. Tortell
Biogeosciences, 16, 1381–1399, https://doi.org/10.5194/bg-16-1381-2019, https://doi.org/10.5194/bg-16-1381-2019, 2019
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Understanding the dynamics of primary productivity requires mechanistic insight into the coupling of light absorption, electron transport and carbon fixation in response to environmental variability. Measuring such rates over diurnal timescales in contrasting regions allowed us to gain information on the regulation of photosynthetic efficiencies, with implications for the interpretation of bio-optical data, and the parameterization of models needed to monitor productivity over large scales.
Mingxi Yang, Thomas G. Bell, Ian J. Brown, James R. Fishwick, Vassilis Kitidis, Philip D. Nightingale, Andrew P. Rees, and Timothy J. Smyth
Biogeosciences, 16, 961–978, https://doi.org/10.5194/bg-16-961-2019, https://doi.org/10.5194/bg-16-961-2019, 2019
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We quantify the emissions and uptake of the greenhouse gases carbon dioxide and methane from the coastal seas of the UK over 1 year using the state-of-the-art eddy covariance technique. Our measurements show how these air–sea fluxes vary twice a day (tidal), diurnally (circadian) and seasonally. We also estimate the air–sea gas transfer velocity, which is essential for modelling and predicting coastal air-sea exchange.
Gwenaël Abril and Alberto V. Borges
Biogeosciences, 16, 769–784, https://doi.org/10.5194/bg-16-769-2019, https://doi.org/10.5194/bg-16-769-2019, 2019
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Based on classical concepts in ecology, and a literature survey, we highlight the importance of flooded land as a preferential source of atmospheric carbon to aquatic systems at the global scale. Studies in terrestrial and aquatic ecosystems could be reconciled by considering the occurrence of an efficient wetland CO2 pump to river systems. New methodological approaches coupling hydrology and ecology are also necessary to improve scientific knowledge on carbon fluxes at the land–water interface.
Hagen Radtke, Marko Lipka, Dennis Bunke, Claudia Morys, Jana Woelfel, Bronwyn Cahill, Michael E. Böttcher, Stefan Forster, Thomas Leipe, Gregor Rehder, and Thomas Neumann
Geosci. Model Dev., 12, 275–320, https://doi.org/10.5194/gmd-12-275-2019, https://doi.org/10.5194/gmd-12-275-2019, 2019
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This paper describes a coupled benthic–pelagic biogeochemical model, ERGOM-SED. We demonstrate its use in a one-dimensional physical model, which is horizontally integrated and vertically resolved. We describe the application of the model to seven stations in the south-western Baltic Sea. The model was calibrated using pore water profiles from these stations. We compare the model results to these and to measured sediment compositions, benthopelagic fluxes and bioturbation intensities.
Beate Stawiarski, Stefan Otto, Volker Thiel, Ulf Gräwe, Natalie Loick-Wilde, Anna K. Wittenborn, Stefan Schloemer, Janine Wäge, Gregor Rehder, Matthias Labrenz, Norbert Wasmund, and Oliver Schmale
Biogeosciences, 16, 1–16, https://doi.org/10.5194/bg-16-1-2019, https://doi.org/10.5194/bg-16-1-2019, 2019
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The understanding of surface water methane production in the world oceans is still poor. By combining field studies and incubation experiments, our investigations suggest that zooplankton contributes to subthermocline methane enrichments in the central Baltic Sea by methane production within the digestive tract of copepods and/or by methane production through release of methane precursor substances into the surrounding water, followed by microbial degradation to methane.
Corinne Le Quéré, Robbie M. Andrew, Pierre Friedlingstein, Stephen Sitch, Judith Hauck, Julia Pongratz, Penelope A. Pickers, Jan Ivar Korsbakken, Glen P. Peters, Josep G. Canadell, Almut Arneth, Vivek K. Arora, Leticia Barbero, Ana Bastos, Laurent Bopp, Frédéric Chevallier, Louise P. Chini, Philippe Ciais, Scott C. Doney, Thanos Gkritzalis, Daniel S. Goll, Ian Harris, Vanessa Haverd, Forrest M. Hoffman, Mario Hoppema, Richard A. Houghton, George Hurtt, Tatiana Ilyina, Atul K. Jain, Truls Johannessen, Chris D. Jones, Etsushi Kato, Ralph F. Keeling, Kees Klein Goldewijk, Peter Landschützer, Nathalie Lefèvre, Sebastian Lienert, Zhu Liu, Danica Lombardozzi, Nicolas Metzl, David R. Munro, Julia E. M. S. Nabel, Shin-ichiro Nakaoka, Craig Neill, Are Olsen, Tsueno Ono, Prabir Patra, Anna Peregon, Wouter Peters, Philippe Peylin, Benjamin Pfeil, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Laure Resplandy, Eddy Robertson, Matthias Rocher, Christian Rödenbeck, Ute Schuster, Jörg Schwinger, Roland Séférian, Ingunn Skjelvan, Tobias Steinhoff, Adrienne Sutton, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Francesco N. Tubiello, Ingrid T. van der Laan-Luijkx, Guido R. van der Werf, Nicolas Viovy, Anthony P. Walker, Andrew J. Wiltshire, Rebecca Wright, Sönke Zaehle, and Bo Zheng
Earth Syst. Sci. Data, 10, 2141–2194, https://doi.org/10.5194/essd-10-2141-2018, https://doi.org/10.5194/essd-10-2141-2018, 2018
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The Global Carbon Budget 2018 describes the data sets and methodology used to quantify the emissions of carbon dioxide and their partitioning among the atmosphere, land, and ocean. These living data are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
Xi Wen, Viktoria Unger, Gerald Jurasinski, Franziska Koebsch, Fabian Horn, Gregor Rehder, Torsten Sachs, Dominik Zak, Gunnar Lischeid, Klaus-Holger Knorr, Michael E. Böttcher, Matthias Winkel, Paul L. E. Bodelier, and Susanne Liebner
Biogeosciences, 15, 6519–6536, https://doi.org/10.5194/bg-15-6519-2018, https://doi.org/10.5194/bg-15-6519-2018, 2018
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Rewetting drained peatlands may lead to prolonged emission of the greenhouse gas methane, but the underlying factors are not well described. In this study, we found two rewetted fens with known high methane fluxes had a high ratio of microbial methane producers to methane consumers and a low abundance of methane consumers compared to pristine wetlands. We therefore suggest abundances of methane-cycling microbes as potential indicators for prolonged high methane emissions in rewetted peatlands.
Chris J. Daniels, Alex J. Poulton, William M. Balch, Emilio Marañón, Tim Adey, Bruce C. Bowler, Pedro Cermeño, Anastasia Charalampopoulou, David W. Crawford, Dave Drapeau, Yuanyuan Feng, Ana Fernández, Emilio Fernández, Glaucia M. Fragoso, Natalia González, Lisa M. Graziano, Rachel Heslop, Patrick M. Holligan, Jason Hopkins, María Huete-Ortega, David A. Hutchins, Phoebe J. Lam, Michael S. Lipsen, Daffne C. López-Sandoval, Socratis Loucaides, Adrian Marchetti, Kyle M. J. Mayers, Andrew P. Rees, Cristina Sobrino, Eithne Tynan, and Toby Tyrrell
Earth Syst. Sci. Data, 10, 1859–1876, https://doi.org/10.5194/essd-10-1859-2018, https://doi.org/10.5194/essd-10-1859-2018, 2018
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Calcifying marine algae (coccolithophores) are key to oceanic biogeochemical processes, such as calcium carbonate production and export. We compile a global database of calcium carbonate production from field samples (n = 2756), alongside primary production rates and coccolithophore abundance. Basic statistical analysis highlights global distribution, average surface and integrated rates, patterns with depth and the importance of considering cell-normalised rates as a simple physiological index.
Murray J. Smith, Carolyn F. Walker, Thomas G. Bell, Mike J. Harvey, Eric S. Saltzman, and Cliff S. Law
Atmos. Chem. Phys., 18, 5861–5877, https://doi.org/10.5194/acp-18-5861-2018, https://doi.org/10.5194/acp-18-5861-2018, 2018
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The transfer of gases across the air–sea interface has a significant influence on climate. During a research voyage in the South Pacific we measured the transfer rate of the biogenic gas dimethyl sulfide (DMS) from the ocean using two independent methods. The agreement between the techniques provides confidence in their use in compilations of global gas transfer. We also identified physical conditions under which the observations are not well predicted by a standard gas transfer model.
Tereza Jarníková, John Dacey, Martine Lizotte, Maurice Levasseur, and Philippe Tortell
Biogeosciences, 15, 2449–2465, https://doi.org/10.5194/bg-15-2449-2018, https://doi.org/10.5194/bg-15-2449-2018, 2018
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This paper presents some of the first high-resolution measurements of a biologically-produced climate-active sulfur gas (dimethylsulfide – DMS) ever made in the Canadian Arctic, taken using two novel high-resolution sampling techniques aboard an icebreaker in the summer of 2015. We show increased concentrations of DMS and its precursors in frontal zones and areas of high sea ice accumulation. Our results provide a snapshot of climate-active gas dynamics in a rapidly changing Arctic.
Trent R. Marwick, Fredrick Tamooh, Bernard Ogwoka, Alberto V. Borges, François Darchambeau, and Steven Bouillon
Biogeosciences, 15, 1683–1700, https://doi.org/10.5194/bg-15-1683-2018, https://doi.org/10.5194/bg-15-1683-2018, 2018
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A 2-year biogeochemical record provides annual sediment and element flux estimates for the non-dammed Sabaki River, Kenya, establishing a baseline for future research in light of impending construction of the first major upstream reservoir. Over 80 % of material fluxes occur across the wet season, with annual yields comparable to the adjacent, and dammed, Tana River. Observations at low-flow periods suggest large mammalian herbivores may be vectors of terrestrial subsidies to the water column.
Corinne Le Quéré, Robbie M. Andrew, Pierre Friedlingstein, Stephen Sitch, Julia Pongratz, Andrew C. Manning, Jan Ivar Korsbakken, Glen P. Peters, Josep G. Canadell, Robert B. Jackson, Thomas A. Boden, Pieter P. Tans, Oliver D. Andrews, Vivek K. Arora, Dorothee C. E. Bakker, Leticia Barbero, Meike Becker, Richard A. Betts, Laurent Bopp, Frédéric Chevallier, Louise P. Chini, Philippe Ciais, Catherine E. Cosca, Jessica Cross, Kim Currie, Thomas Gasser, Ian Harris, Judith Hauck, Vanessa Haverd, Richard A. Houghton, Christopher W. Hunt, George Hurtt, Tatiana Ilyina, Atul K. Jain, Etsushi Kato, Markus Kautz, Ralph F. Keeling, Kees Klein Goldewijk, Arne Körtzinger, Peter Landschützer, Nathalie Lefèvre, Andrew Lenton, Sebastian Lienert, Ivan Lima, Danica Lombardozzi, Nicolas Metzl, Frank Millero, Pedro M. S. Monteiro, David R. Munro, Julia E. M. S. Nabel, Shin-ichiro Nakaoka, Yukihiro Nojiri, X. Antonio Padin, Anna Peregon, Benjamin Pfeil, Denis Pierrot, Benjamin Poulter, Gregor Rehder, Janet Reimer, Christian Rödenbeck, Jörg Schwinger, Roland Séférian, Ingunn Skjelvan, Benjamin D. Stocker, Hanqin Tian, Bronte Tilbrook, Francesco N. Tubiello, Ingrid T. van der Laan-Luijkx, Guido R. van der Werf, Steven van Heuven, Nicolas Viovy, Nicolas Vuichard, Anthony P. Walker, Andrew J. Watson, Andrew J. Wiltshire, Sönke Zaehle, and Dan Zhu
Earth Syst. Sci. Data, 10, 405–448, https://doi.org/10.5194/essd-10-405-2018, https://doi.org/10.5194/essd-10-405-2018, 2018
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The Global Carbon Budget 2017 describes data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. It is the 12th annual update and the 6th published in this journal.
Tom Jilbert, Eero Asmala, Christian Schröder, Rosa Tiihonen, Jukka-Pekka Myllykangas, Joonas J. Virtasalo, Aarno Kotilainen, Pasi Peltola, Päivi Ekholm, and Susanna Hietanen
Biogeosciences, 15, 1243–1271, https://doi.org/10.5194/bg-15-1243-2018, https://doi.org/10.5194/bg-15-1243-2018, 2018
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Iron is a common dissolved element in river water, recognizable by its orange-brown colour. Here we show that when rivers reach the ocean much of this iron settles to the sediments by a process known as flocculation. The iron is then used by microbes in coastal sediments, which are important hotspots in the global carbon cycle.
Alberto V. Borges, Gwenaël Abril, and Steven Bouillon
Biogeosciences, 15, 1093–1114, https://doi.org/10.5194/bg-15-1093-2018, https://doi.org/10.5194/bg-15-1093-2018, 2018
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The Mekong River is among the largest on Earth and is vital for the economy of Vietnam and South East Asia and the livelihood of the local population (70 million across six countries). Numerous dams for hydropower are planned, which will affect the delivery of water and sediments to the Mekong delta, with numerous possible consequences. We report the dynamics of two greenhouse gases (CO2 and CH4) in the Mekong delta that can be used as a reference state to evaluate future changes.
Yuanyuan Feng, Michael Y. Roleda, Evelyn Armstrong, Cliff S. Law, Philip W. Boyd, and Catriona L. Hurd
Biogeosciences, 15, 581–595, https://doi.org/10.5194/bg-15-581-2018, https://doi.org/10.5194/bg-15-581-2018, 2018
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We conducted a series of incubation experiments to understand how the changes in five environmental drivers will affect the elemental composition of the calcifying phytoplankton species Emiliania huxleyi. These findings provide new diagnostic information to aid our understanding of how the physiology and the related marine biogeochemistry of the ecologically important species Emiliania huxleyi will respond to changes in different environmental drivers in the global climate change scenario.
Johanna Maltby, Lea Steinle, Carolin R. Löscher, Hermann W. Bange, Martin A. Fischer, Mark Schmidt, and Tina Treude
Biogeosciences, 15, 137–157, https://doi.org/10.5194/bg-15-137-2018, https://doi.org/10.5194/bg-15-137-2018, 2018
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The activity and environmental controls of methanogenesis (MG) within the sulfate-reducing zone (0–30 cm below the seafloor) were investigated in organic-rich sediments of the seasonally hypoxic Eckernförde Bay, SW Baltic Sea. MG activity was mostly linked to non-competitive substrates. The major controls identified were organic matter availability, C / N, temperature, and O2 in the water column, revealing higher rates in warm, stratified, hypoxic seasons compared to colder, oxygenated seasons.
Eike E. Köhn, Sören Thomsen, Damian L. Arévalo-Martínez, and Torsten Kanzow
Ocean Sci., 13, 1017–1033, https://doi.org/10.5194/os-13-1017-2017, https://doi.org/10.5194/os-13-1017-2017, 2017
Martine Lizotte, Maurice Levasseur, Cliff S. Law, Carolyn F. Walker, Karl A. Safi, Andrew Marriner, and Ronald P. Kiene
Ocean Sci., 13, 961–982, https://doi.org/10.5194/os-13-961-2017, https://doi.org/10.5194/os-13-961-2017, 2017
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During a 4-week oceanographic cruise in 2012, we investigated the water masses bordering the subtropical front near New Zealand as sources of the biogenic gas dimethyl sulfide (DMS). DMS oxidation products may influence the atmospheric radiative budget of the Earth. Concentrations of DMS were high in the study region and DMS's precursor, dimethylsulfoniopropionate, showed a strong association with phytoplankton biomass in relation to the persistent dominance of dinoflagellates/coccolithophores.
Cliff S. Law, Murray J. Smith, Mike J. Harvey, Thomas G. Bell, Luke T. Cravigan, Fiona C. Elliott, Sarah J. Lawson, Martine Lizotte, Andrew Marriner, John McGregor, Zoran Ristovski, Karl A. Safi, Eric S. Saltzman, Petri Vaattovaara, and Carolyn F. Walker
Atmos. Chem. Phys., 17, 13645–13667, https://doi.org/10.5194/acp-17-13645-2017, https://doi.org/10.5194/acp-17-13645-2017, 2017
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We carried out a multidisciplinary study to examine how aerosol production is influenced by the production and emission of trace gases and particles in the surface ocean. Phytoplankton blooms of different species composition in frontal waters southeast of New Zealand were a significant source of dimethylsulfide and other aerosol precursors. The relationships between surface ocean biogeochemistry and aerosol composition will inform the understanding of aerosol production over the remote ocean.
Alexander Galán, Bo Thamdrup, Gonzalo S. Saldías, and Laura Farías
Biogeosciences, 14, 4795–4813, https://doi.org/10.5194/bg-14-4795-2017, https://doi.org/10.5194/bg-14-4795-2017, 2017
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This investigation characterizes the variability of pathways involved in N loss in the water column over the continental shelf off central Chile during the development of the upwelling season. Our results highlight the links between several pathways involved in N removal, and considering the extreme variation in oxygen observed could help to understand the ecological and biogeochemical implications due to global warming when intensification and/or expansion of the oceanic OMZs are projected.
Jukka-Pekka Myllykangas, Tom Jilbert, Gunnar Jakobs, Gregor Rehder, Jan Werner, and Susanna Hietanen
Earth Syst. Dynam., 8, 817–826, https://doi.org/10.5194/esd-8-817-2017, https://doi.org/10.5194/esd-8-817-2017, 2017
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The deep waters of the Baltic Sea host an expanding
dead zone, where low-oxygen conditions favour the natural production of two strong greenhouse gases, methane and nitrous oxide. Oxygen is introduced into the deeps only during rare
salt pulses. We studied the effects of a recent salt pulse on Baltic greenhouse gas production. We found that where oxygen was introduced, methane was largely removed, while nitrous oxide production increased, indicating strong effects on greenhouse gas dynamics.
Chun-Ying Liu, Wei-Hua Feng, Ye Tian, Gui-Peng Yang, Pei-Feng Li, and Hermann W. Bange
Ocean Sci., 13, 623–632, https://doi.org/10.5194/os-13-623-2017, https://doi.org/10.5194/os-13-623-2017, 2017
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We developed a new method for the determination of dissolved nitric oxide (NO) in discrete seawater samples based on the combination of a purge-and-trap setup and a fluorometric detection of NO. With this method we have a reliable and comparably easy to use method to measure oceanic NO surface concentrations, which can be used to decipher both its temporal and spatial distributions as well as its biogeochemical pathways in the oceans.
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
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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.
Robert C. Upstill-Goddard, Matthew E. Salter, Paul J. Mann, Jonathan Barnes, John Poulsen, Bienvenu Dinga, Gregory J. Fiske, and Robert M. Holmes
Biogeosciences, 14, 2267–2281, https://doi.org/10.5194/bg-14-2267-2017, https://doi.org/10.5194/bg-14-2267-2017, 2017
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We measured concentrations of the greenhouse gases methane and nitrous oxide in rivers from the western Congo Basin (Republic of Congo). All rivers studied were strong sources of methane to air but they ranged from minor sources to minor sinks for nitrous oxide. Our estimated emissions to air agreed with existing estimates for sub-Saharan African rivers, supportive of the growing consensus that African river systems are a major contributor to the global freshwater source of greenhouse gases.
Anja Engel, Hannes Wagner, Frédéric A. C. Le Moigne, and Samuel T. Wilson
Biogeosciences, 14, 1825–1838, https://doi.org/10.5194/bg-14-1825-2017, https://doi.org/10.5194/bg-14-1825-2017, 2017
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To better understand the role of oxygen for the biological carbon pump, we studied particle fluxes through hypoxic waters in the eastern tropical North Atlantic. Attenuation of organic carbon fluxes over depth was lower than expected from seawater temperatures, indicating co-effects of oxygen concentration. Differences were observed for individual organic components, suggesting that future carbon export fluxes may depend on changes in surface ocean organic matter quality under global change.
Lea Steinle, Johanna Maltby, Tina Treude, Annette Kock, Hermann W. Bange, Nadine Engbersen, Jakob Zopfi, Moritz F. Lehmann, and Helge Niemann
Biogeosciences, 14, 1631–1645, https://doi.org/10.5194/bg-14-1631-2017, https://doi.org/10.5194/bg-14-1631-2017, 2017
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Large amounts of methane are produced in anoxic, coastal sediments, from which it can seep into the overlying water column. Aerobic oxidation of methane (MOx) mediated by methanotrophic bacteria is an important sink for methane before its evasion to the atmosphere. In a 2-year seasonal study, we investigated the spatio-temporal variability of MOx in a seasonally hypoxic coastal inlet using radiotracer-based methods. In experiments, we assessed the effect of variable oxygen concentrations on MOx.
Naomi Geeraert, Fred O. Omengo, Fredrick Tamooh, Trent R. Marwick, Alberto V. Borges, Gerard Govers, and Steven Bouillon
Biogeosciences Discuss., https://doi.org/10.5194/bg-2017-31, https://doi.org/10.5194/bg-2017-31, 2017
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We observed that the relationship between the concentrations and the water discharge in the Tana River changed in wet seasons with and without flooding. Detailed sampling in those seasons is required in order to construct several rating curves and to obtain reliable flux estimates. The sediment and carbon fluxes in function of discharge will help us to asses the flux changes that can be expected when the hydrology changes due to climate change or human impact.
Sinikka T. Lennartz, Christa A. Marandino, Marc von Hobe, Pau Cortes, Birgit Quack, Rafel Simo, Dennis Booge, Andrea Pozzer, Tobias Steinhoff, Damian L. Arevalo-Martinez, Corinna Kloss, Astrid Bracher, Rüdiger Röttgers, Elliot Atlas, and Kirstin Krüger
Atmos. Chem. Phys., 17, 385–402, https://doi.org/10.5194/acp-17-385-2017, https://doi.org/10.5194/acp-17-385-2017, 2017
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We present new sea surface and marine boundary layer measurements of carbonyl sulfide, the most abundant sulfur gas in the atmosphere, and calculate an oceanic emission estimate. Our results imply that oceanic emissions are very unlikely to account for the missing source in the atmospheric budget that is currently discussed for OCS.
Thibault Lambert, Steven Bouillon, François Darchambeau, Philippe Massicotte, and Alberto V. Borges
Biogeosciences, 13, 5405–5420, https://doi.org/10.5194/bg-13-5405-2016, https://doi.org/10.5194/bg-13-5405-2016, 2016
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This paper aims to investigate the spatial variability in dissolved organic matter (DOM) in terms of both concentration and composition in the Congo River network. Stable carbon isotopes and absorption and fluorescent properties of DOM were used as proxies for DOM composition. This study shows that DOM degradation within the Congo Basin results in the transition from aromatic to aliphatic DOM as well as the role of landscape and water residence time on this transition.
Carolyn F. Walker, Mike J. Harvey, Murray J. Smith, Thomas G. Bell, Eric S. Saltzman, Andrew S. Marriner, John A. McGregor, and Cliff S. Law
Ocean Sci., 12, 1033–1048, https://doi.org/10.5194/os-12-1033-2016, https://doi.org/10.5194/os-12-1033-2016, 2016
James H. Butler, Shari A. Yvon-Lewis, Jurgen M. Lobert, Daniel B. King, Stephen A. Montzka, John L. Bullister, Valentin Koropalov, James W. Elkins, Bradley D. Hall, Lei Hu, and Yina Liu
Atmos. Chem. Phys., 16, 10899–10910, https://doi.org/10.5194/acp-16-10899-2016, https://doi.org/10.5194/acp-16-10899-2016, 2016
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This study was conducted to understand the influence of the ocean on the lifetime of atmospheric carbon tetrachloride, a strong, ozone-depleting gas. Data from 16 research cruises conducted between 1987 and 2010 show that, unlike the unreactive chlorofluorocarbons, carbon tetrachloride is undersaturated in surface waters regardless of temperature, wind, or biological regime, but with larger undersaturations with upwelling. Results suggest that the ocean consumes about 18 % of atmospheric CCl4.
Timothy J. Burrell, Elizabeth W. Maas, Paul Teesdale-Spittle, and Cliff S. Law
Biogeosciences, 13, 4379–4388, https://doi.org/10.5194/bg-13-4379-2016, https://doi.org/10.5194/bg-13-4379-2016, 2016
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Bacterial extracellular enzymes play a significant role in the degradation of organic matter in the open ocean. Using artificial fluorogenic substrates, this research highlights potential artefacts in the response of bacterial glucosidase and aminopeptidase to ocean acidification, and the effects of three different acidification techniques. We conclude that fluorogenic substrate degradation is affected by, or alters pH, and bubbling CO2 may lead to the overestimation of carbohydrate degradation.
Fleur A. E. Roland, François Darchambeau, Cédric Morana, Sean A. Crowe, Bo Thamdrup, and Alberto V. Borges
Biogeosciences Discuss., https://doi.org/10.5194/bg-2016-300, https://doi.org/10.5194/bg-2016-300, 2016
Manuscript not accepted for further review
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We studied methane consumption in a tropical Great Lake (Lake Kivu, East Africa). Lake Kivu has huge methane concentrations in its deep anoxic waters, but is a very poor emitter of methane to the atmosphere, which suppose a strong methane consumption in the water column. During this study, we put in evidence high aerobic and anaerobic consumption rates, whose relative importance varied with the season (higher aerobic rates in dry season, when the oxic compartment is wider).
R. Pereira, K. Schneider-Zapp, and R. C. Upstill-Goddard
Biogeosciences, 13, 3981–3989, https://doi.org/10.5194/bg-13-3981-2016, https://doi.org/10.5194/bg-13-3981-2016, 2016
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Understanding controls of air–sea gas exchange is necessary for predicting regional- and global-scale trace gas fluxes and feedbacks. Recent studies demonstrated the importance of surfactants, which occur naturally in the uppermost layer of coastal water bodies, to suppress the gas transfer velocity (kw). Here we present data for seawater samples collected from the North Sea. Using a novel analytical approach we show a strong seasonal and spatial relationship between natural surfactants and kw.
Lothar Stramma, Tim Fischer, Damian S. Grundle, Gerd Krahmann, Hermann W. Bange, and Christa A. Marandino
Ocean Sci., 12, 861–873, https://doi.org/10.5194/os-12-861-2016, https://doi.org/10.5194/os-12-861-2016, 2016
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Results from a research cruise on R/V Sonne to the eastern tropical Pacific in October 2015 during the 2015–2016 El Niño show the transition of current, hydrographic, and nutrient conditions to El Niño conditions in the eastern tropical Pacific in October 2015. Although in early 2015 the El Niño was strong and in October 2015 showed a clear El Niño influence on the EUC, in the eastern tropical Pacific the measurements only showed developing El Niño water mass distributions.
Carolin R. Löscher, Hermann W. Bange, Ruth A. Schmitz, Cameron M. Callbeck, Anja Engel, Helena Hauss, Torsten Kanzow, Rainer Kiko, Gaute Lavik, Alexandra Loginova, Frank Melzner, Judith Meyer, Sven C. Neulinger, Markus Pahlow, Ulf Riebesell, Harald Schunck, Sören Thomsen, and Hannes Wagner
Biogeosciences, 13, 3585–3606, https://doi.org/10.5194/bg-13-3585-2016, https://doi.org/10.5194/bg-13-3585-2016, 2016
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The ocean loses oxygen due to climate change. Addressing this issue in tropical ocean regions (off Peru and Mauritania), we aimed to understand the effects of oxygen depletion on various aspects of marine biogeochemistry, including primary production and export production, the nitrogen cycle, greenhouse gas production, organic matter fluxes and remineralization, and the role of zooplankton and viruses.
Darren R. Clark, Claire E. Widdicombe, Andrew P. Rees, and E. Malcolm S. Woodward
Biogeosciences, 13, 2873–2888, https://doi.org/10.5194/bg-13-2873-2016, https://doi.org/10.5194/bg-13-2873-2016, 2016
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Based in the Mauritanian upwelling system, the article describes a Lagrangian study of biogeochemical processes within a freshly upwelled body of water as it advects offshore. We report rates of primary production, nitrogen assimilation, and regeneration and describe how these processes relate to the dynamics of the upwelling regime. This system is perhaps the least studied of the four major eastern boundary upwelling systems and so these measurements provide important new insights.
Carolin R. Löscher, Annie Bourbonnais, Julien Dekaezemacker, Chawalit N. Charoenpong, Mark A. Altabet, Hermann W. Bange, Rena Czeschel, Chris Hoffmann, and Ruth Schmitz
Biogeosciences, 13, 2889–2899, https://doi.org/10.5194/bg-13-2889-2016, https://doi.org/10.5194/bg-13-2889-2016, 2016
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The ocean is full of eddies and they play a key role for ocean biogeochemistry. In order to understand dinitrogen (N2) fixation, one major control of oceanic primary production, we investigated three eddies in the eastern tropical South Pacific off Peru. We conducted the first detailed survey and found increased N2 fixation in the oxygen-depleted cores of anticyclonic mode water eddies. Taken together, we could – for the first time – show that eddies play an important role in N2 fixation off Peru.
Thibault Lambert, Cristian R. Teodoru, Frank C. Nyoni, Steven Bouillon, François Darchambeau, Philippe Massicotte, and Alberto V. Borges
Biogeosciences, 13, 2727–2741, https://doi.org/10.5194/bg-13-2727-2016, https://doi.org/10.5194/bg-13-2727-2016, 2016
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This manuscript presents a detailed analysis of transport and transformation of dissolved organic matter along the Zambezi River and its largest tributary. A particular focus is put on the effects of floodplains/wetlands and reservoirs as well as low-flow vs. high-flow conditions on the longitudinal patterns in DOM concentration and composition. It is the first study to present such a detailed analysis for a whole, large river system, and in particular for a tropical river other than the Amazon.
Denise Müller, Hermann W. Bange, Thorsten Warneke, Tim Rixen, Moritz Müller, Aazani Mujahid, and Justus Notholt
Biogeosciences, 13, 2415–2428, https://doi.org/10.5194/bg-13-2415-2016, https://doi.org/10.5194/bg-13-2415-2016, 2016
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Estuaries act as sources of the greenhouse gases nitrous oxide (N2O) and methane (CH4) to the atmosphere. We provide first measurements of N2O and CH4 in two estuaries in north-western Borneo, a region which is dominated by peatlands. We show that N2O and CH4 concentrations in these estuaries are moderate despite high organic carbon loads, that nutrient enhancement does not lead to enhanced N2O emissions, and that the wet season dominates the variability of the emissions in these systems.
Happy Hu, Annie Bourbonnais, Jennifer Larkum, Hermann W. Bange, and Mark A. Altabet
Biogeosciences, 13, 1453–1468, https://doi.org/10.5194/bg-13-1453-2016, https://doi.org/10.5194/bg-13-1453-2016, 2016
Damian L. Arévalo-Martínez, Annette Kock, Carolin R. Löscher, Ruth A. Schmitz, Lothar Stramma, and Hermann W. Bange
Biogeosciences, 13, 1105–1118, https://doi.org/10.5194/bg-13-1105-2016, https://doi.org/10.5194/bg-13-1105-2016, 2016
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We present the first measurements of N2O across three mesoscale eddies in the eastern tropical South Pacific. Eddie's vertical structure, offshore transport, properties during its formation and near-surface primary production determined the N2O distribution. Substantial depletion of N2O within the core of anticyclonic eddies suggests that although these are transient features, N-loss processes within their centres can lead to an enhanced N2O sink which is not accounted for in marine N2O budgets.
A. Kock, D. L. Arévalo-Martínez, C. R. Löscher, and H. W. Bange
Biogeosciences, 13, 827–840, https://doi.org/10.5194/bg-13-827-2016, https://doi.org/10.5194/bg-13-827-2016, 2016
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We measured the nitrous oxide (N2O) distribution in the water column in the oxygen minimum zone off Peru, an area with extremely high N2O emissions. Our data show very variable and often very high N2O concentrations in the water column at the coast, which lead to high N2O emissions when these waters are brought to the surface. The very high N2O production off Peru may be caused by high nutrient turnover rates together with rapid changes in the oxygen concentrations.
A. R. Baker, M. Thomas, H. W. Bange, and E. Plasencia Sánchez
Biogeosciences, 13, 817–825, https://doi.org/10.5194/bg-13-817-2016, https://doi.org/10.5194/bg-13-817-2016, 2016
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Concentrations of major ions and trace metals were measured in aerosols off the coast of Peru in December 2012. A few trace metals (iron, copper, nickel, and cobalt) had anomalously high concentrations, which may be associated with industrial metal smelting activities in the region. The atmosphere appears to supply an excess of iron (relative to atmospheric nitrogen supply) to the phytoplankton community of the Peruvian upwelling system.
D. Müller, T. Warneke, T. Rixen, M. Müller, A. Mujahid, H. W. Bange, and J. Notholt
Biogeosciences, 13, 691–705, https://doi.org/10.5194/bg-13-691-2016, https://doi.org/10.5194/bg-13-691-2016, 2016
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We studied organic carbon and the dissolved greenhouse gases carbon dioxide (CO2) and carbon monoxide (CO) in two estuaries in Sarawak, Malaysia, whose coast is covered by carbon-rich peatlands. The estuaries received terrestrial organic carbon from peat-draining tributaries. A large fraction was converted to CO2 and a minor fraction to CO. Both gases were released to the atmosphere. This shows how these estuaries function as efficient filters between land and ocean in this important region.
W. K. Oestreich, N. K. Ganju, J. W. Pohlman, and S. E. Suttles
Biogeosciences, 13, 583–595, https://doi.org/10.5194/bg-13-583-2016, https://doi.org/10.5194/bg-13-583-2016, 2016
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Colored dissolved organic matter (CDOM) is a factor in determining penetration of light in estuaries. Important plant species growing in the beds of estuaries depend on such light penetration for survival. Previous studies have used CDOM fluorescence to approximate light absorption by CDOM but have found variable relationships between fluorescence and absorbance. This paper describes this variability in three east coast estuaries, and shows that this conversion is dependent on CDOM source.
S. Walter, A. Kock, T. Steinhoff, B. Fiedler, P. Fietzek, J. Kaiser, M. Krol, M. E. Popa, Q. Chen, T. Tanhua, and T. Röckmann
Biogeosciences, 13, 323–340, https://doi.org/10.5194/bg-13-323-2016, https://doi.org/10.5194/bg-13-323-2016, 2016
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Oceans are a source of H2, an indirect greenhouse gas. Measurements constraining the temporal and spatial patterns of oceanic H2 emissions are sparse and although H2 is assumed to be produced mainly biologically, direct evidence for biogenic marine production was lacking. By analyzing the H2 isotopic composition (δD) we were able to constrain the global H2 budget in more detail, verify biogenic production and point to additional sources. We also showed that current models are reasonably working.
C. Le Quéré, R. Moriarty, R. M. Andrew, J. G. Canadell, S. Sitch, J. I. Korsbakken, P. Friedlingstein, G. P. Peters, R. J. Andres, T. A. Boden, R. A. Houghton, J. I. House, R. F. Keeling, P. Tans, A. Arneth, D. C. E. Bakker, L. Barbero, L. Bopp, J. Chang, F. Chevallier, L. P. Chini, P. Ciais, M. Fader, R. A. Feely, T. Gkritzalis, I. Harris, J. Hauck, T. Ilyina, A. K. Jain, E. Kato, V. Kitidis, K. Klein Goldewijk, C. Koven, P. Landschützer, S. K. Lauvset, N. Lefèvre, A. Lenton, I. D. Lima, N. Metzl, F. Millero, D. R. Munro, A. Murata, J. E. M. S. Nabel, S. Nakaoka, Y. Nojiri, K. O'Brien, A. Olsen, T. Ono, F. F. Pérez, B. Pfeil, D. Pierrot, B. Poulter, G. Rehder, C. Rödenbeck, S. Saito, U. Schuster, J. Schwinger, R. Séférian, T. Steinhoff, B. D. Stocker, A. J. Sutton, T. Takahashi, B. Tilbrook, I. T. van der Laan-Luijkx, G. R. van der Werf, S. van Heuven, D. Vandemark, N. Viovy, A. Wiltshire, S. Zaehle, and N. Zeng
Earth Syst. Sci. Data, 7, 349–396, https://doi.org/10.5194/essd-7-349-2015, https://doi.org/10.5194/essd-7-349-2015, 2015
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Accurate assessment of anthropogenic carbon dioxide emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere is important to understand the global carbon cycle, support the development of climate policies, and project future climate change. We describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, based on a range of data and models and their interpretation by a broad scientific community.
H. E. Lutterbeck and H. W. Bange
Ocean Sci., 11, 937–946, https://doi.org/10.5194/os-11-937-2015, https://doi.org/10.5194/os-11-937-2015, 2015
T. Stöven, T. Tanhua, M. Hoppema, and J. L. Bullister
Ocean Sci., 11, 699–718, https://doi.org/10.5194/os-11-699-2015, https://doi.org/10.5194/os-11-699-2015, 2015
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We use a suite of transient tracer measurements from a Southern Ocean sector southeast of Africa collected from 1998 and 2012 to quantify ventilation and change in ventilation. We found that the ventilation can be constrained by an inverse Gaussian transit time distribution north of the Subantarctic Front. We do not find any significant changes in upper ocean ventilation during this time period.
C. Morana, F. Darchambeau, F. A. E. Roland, A. V. Borges, F. Muvundja, Z. Kelemen, P. Masilya, J.-P. Descy, and S. Bouillon
Biogeosciences, 12, 4953–4963, https://doi.org/10.5194/bg-12-4953-2015, https://doi.org/10.5194/bg-12-4953-2015, 2015
M.-S. Sun, G.-L. Zhang, X.-P. Cao, X.-Y. Mao, J. Li, and W.-W. Ye
Biogeosciences Discuss., https://doi.org/10.5194/bgd-12-7017-2015, https://doi.org/10.5194/bgd-12-7017-2015, 2015
Revised manuscript not accepted
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Obvious seasonal variations of the distribution and emission of methane in the ECS and YS were reported based on data collected during five cruises in 2011. A box model was used to calculate the methane budget in the ECS, identify the main sources and sinks of dissolved methane in this area, and estimate the contribution of different sources to total methane quantitatively. It indicated that the most important source of methane in the ECS was in situ production in the water column.
C. R. Teodoru, F. C. Nyoni, A. V. Borges, F. Darchambeau, I. Nyambe, and S. Bouillon
Biogeosciences, 12, 2431–2453, https://doi.org/10.5194/bg-12-2431-2015, https://doi.org/10.5194/bg-12-2431-2015, 2015
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CO2 and CH4 concentrations and fluxes in the Zambezi River basin are well below the median/average values reported previously for tropical rivers, streams and reservoirs, and mainly controlled by the connectivity with floodplains and the presence of waterfalls and man-made reservoirs. The mass balance suggests that carbon transport to the ocean represents the major component (~60%) of the budget, while emissions to the atmosphere account for less than 40% of the total carbon yield.
T. J. Burrell, E. W. Maas, P. Teesdale-Spittle, and C. S. Law
Biogeosciences Discuss., https://doi.org/10.5194/bgd-12-5841-2015, https://doi.org/10.5194/bgd-12-5841-2015, 2015
Manuscript not accepted for further review
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pH has a significant effect on the artificial fluorophore for glucosidase and protease activity, while artificial aminopeptidase substrate alters the pH of seawater. Reduction of coastal seawater pH to 7.8 was shown to increase β-glucosidase activity rapidly (0.5h), while no significant response was detected for leucine aminopeptidase. Seawater acidified by bubbling CO2 gas resulted in elevated β-glucosidase activity and bacterial cell numbers, although seasonal effects were observed.
C. Morana, A. V. Borges, F. A. E. Roland, F. Darchambeau, J.-P. Descy, and S. Bouillon
Biogeosciences, 12, 2077–2088, https://doi.org/10.5194/bg-12-2077-2015, https://doi.org/10.5194/bg-12-2077-2015, 2015
M. Hagens, C. P. Slomp, F. J. R. Meysman, D. Seitaj, J. Harlay, A. V. Borges, and J. J. Middelburg
Biogeosciences, 12, 1561–1583, https://doi.org/10.5194/bg-12-1561-2015, https://doi.org/10.5194/bg-12-1561-2015, 2015
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This study looks at the combined impacts of hypoxia and acidification, two major environmental stressors affecting coastal systems, in a seasonally stratified basin. Here, the surface water experiences less seasonality in pH than the bottom water despite higher process rates. This is due to a substantial reduction in the acid-base buffering capacity of the bottom water as it turns hypoxic in summer. This highlights the crucial role of the buffering capacity as a modulating factor in pH dynamics.
T. G. Bell, W. De Bruyn, C. A. Marandino, S. D. Miller, C. S. Law, M. J. Smith, and E. S. Saltzman
Atmos. Chem. Phys., 15, 1783–1794, https://doi.org/10.5194/acp-15-1783-2015, https://doi.org/10.5194/acp-15-1783-2015, 2015
P. Brandt, H. W. Bange, D. Banyte, M. Dengler, S.-H. Didwischus, T. Fischer, R. J. Greatbatch, J. Hahn, T. Kanzow, J. Karstensen, A. Körtzinger, G. Krahmann, S. Schmidtko, L. Stramma, T. Tanhua, and M. Visbeck
Biogeosciences, 12, 489–512, https://doi.org/10.5194/bg-12-489-2015, https://doi.org/10.5194/bg-12-489-2015, 2015
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Our observational study looks at the structure of the eastern tropical North Atlantic (ETNA) oxygen minimum zone (OMZ) in comparison with the less-ventilated, eastern tropical South Pacific OMZ. We quantify the OMZ’s oxygen budget composed of consumption, advection, lateral and vertical mixing. Substantial oxygen variability is observed on interannual to multidecadal timescales. The deoxygenation of the ETNA OMZ during the last decades represents a substantial imbalance of the oxygen budget.
G. Abril, S. Bouillon, F. Darchambeau, C. R. Teodoru, T. R. Marwick, F. Tamooh, F. Ochieng Omengo, N. Geeraert, L. Deirmendjian, P. Polsenaere, and A. V. Borges
Biogeosciences, 12, 67–78, https://doi.org/10.5194/bg-12-67-2015, https://doi.org/10.5194/bg-12-67-2015, 2015
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We compared pCO2 data calculated from pH and alkalinity from those measured directly in a large array of temperate and tropical freshwaters. This revealed a large overestimation (up to 300%) of calculated pCO2 in the case of acidic and organic-rich waters, due to a contribution of organic acids anions to alkalinity and a lower buffering capacity of the carbonate system at acidic pH. Given the widespread distribution of acidic freshwaters, direct measurements of water pCO2 are encouraged.
S. T. Lennartz, A. Lehmann, J. Herrford, F. Malien, H.-P. Hansen, H. Biester, and H. W. Bange
Biogeosciences, 11, 6323–6339, https://doi.org/10.5194/bg-11-6323-2014, https://doi.org/10.5194/bg-11-6323-2014, 2014
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A time series of nine oceanic parameters from the coastal time series station Boknis Eck (BE, southwestern Baltic Sea) in the period of 1957-2013 is analysed with respect to seasonal cycles and long-term trends. Most striking was a paradoxical decreasing trend in oxygen with a simultaneous decline in eutrophication. Possible reasons for this paradox, e.g. processes related to warming temperatures such as increased decomposition of organic matter or altered ventilation, are discussed.
D. R. Clark, I. J. Brown, A. P. Rees, P. J. Somerfield, and P. I. Miller
Biogeosciences, 11, 4985–5005, https://doi.org/10.5194/bg-11-4985-2014, https://doi.org/10.5194/bg-11-4985-2014, 2014
P. Ciais, A. J. Dolman, A. Bombelli, R. Duren, A. Peregon, P. J. Rayner, C. Miller, N. Gobron, G. Kinderman, G. Marland, N. Gruber, F. Chevallier, R. J. Andres, G. Balsamo, L. Bopp, F.-M. Bréon, G. Broquet, R. Dargaville, T. J. Battin, A. Borges, H. Bovensmann, M. Buchwitz, J. Butler, J. G. Canadell, R. B. Cook, R. DeFries, R. Engelen, K. R. Gurney, C. Heinze, M. Heimann, A. Held, M. Henry, B. Law, S. Luyssaert, J. Miller, T. Moriyama, C. Moulin, R. B. Myneni, C. Nussli, M. Obersteiner, D. Ojima, Y. Pan, J.-D. Paris, S. L. Piao, B. Poulter, S. Plummer, S. Quegan, P. Raymond, M. Reichstein, L. Rivier, C. Sabine, D. Schimel, O. Tarasova, R. Valentini, R. Wang, G. van der Werf, D. Wickland, M. Williams, and C. Zehner
Biogeosciences, 11, 3547–3602, https://doi.org/10.5194/bg-11-3547-2014, https://doi.org/10.5194/bg-11-3547-2014, 2014
J. Friedrich, F. Janssen, D. Aleynik, H. W. Bange, N. Boltacheva, M. N. Çagatay, A. W. Dale, G. Etiope, Z. Erdem, M. Geraga, A. Gilli, M. T. Gomoiu, P. O. J. Hall, D. Hansson, Y. He, M. Holtappels, M. K. Kirf, M. Kononets, S. Konovalov, A. Lichtschlag, D. M. Livingstone, G. Marinaro, S. Mazlumyan, S. Naeher, R. P. North, G. Papatheodorou, O. Pfannkuche, R. Prien, G. Rehder, C. J. Schubert, T. Soltwedel, S. Sommer, H. Stahl, E. V. Stanev, A. Teaca, A. Tengberg, C. Waldmann, B. Wehrli, and F. Wenzhöfer
Biogeosciences, 11, 1215–1259, https://doi.org/10.5194/bg-11-1215-2014, https://doi.org/10.5194/bg-11-1215-2014, 2014
R. H. Li, S. M. Liu, Y. W. Li, G. L. Zhang, J. L. Ren, and J. Zhang
Biogeosciences, 11, 481–506, https://doi.org/10.5194/bg-11-481-2014, https://doi.org/10.5194/bg-11-481-2014, 2014
T. R. Marwick, F. Tamooh, B. Ogwoka, C. Teodoru, A. V. Borges, F. Darchambeau, and S. Bouillon
Biogeosciences, 11, 443–460, https://doi.org/10.5194/bg-11-443-2014, https://doi.org/10.5194/bg-11-443-2014, 2014
D. L. Arévalo-Martínez, M. Beyer, M. Krumbholz, I. Piller, A. Kock, T. Steinhoff, A. Körtzinger, and H. W. Bange
Ocean Sci., 9, 1071–1087, https://doi.org/10.5194/os-9-1071-2013, https://doi.org/10.5194/os-9-1071-2013, 2013
G. Jakobs, G. Rehder, G. Jost, K. Kießlich, M. Labrenz, and O. Schmale
Biogeosciences, 10, 7863–7875, https://doi.org/10.5194/bg-10-7863-2013, https://doi.org/10.5194/bg-10-7863-2013, 2013
A. E. Santoro, C. M. Sakamoto, J. M. Smith, J. N. Plant, A. L. Gehman, A. Z. Worden, K. S. Johnson, C. A. Francis, and K. L. Casciotti
Biogeosciences, 10, 7395–7410, https://doi.org/10.5194/bg-10-7395-2013, https://doi.org/10.5194/bg-10-7395-2013, 2013
L. Stramma, H. W. Bange, R. Czeschel, A. Lorenzo, and M. Frank
Biogeosciences, 10, 7293–7306, https://doi.org/10.5194/bg-10-7293-2013, https://doi.org/10.5194/bg-10-7293-2013, 2013
F. Tamooh, A. V. Borges, F. J. R. Meysman, K. Van Den Meersche, F. Dehairs, R. Merckx, and S. Bouillon
Biogeosciences, 10, 6911–6928, https://doi.org/10.5194/bg-10-6911-2013, https://doi.org/10.5194/bg-10-6911-2013, 2013
I.-N. Kim, K. Lee, H. W. Bange, and A. M. Macdonald
Biogeosciences, 10, 6783–6792, https://doi.org/10.5194/bg-10-6783-2013, https://doi.org/10.5194/bg-10-6783-2013, 2013
C. A. Marandino, S. Tegtmeier, K. Krüger, C. Zindler, E. L. Atlas, F. Moore, and H. W. Bange
Atmos. Chem. Phys., 13, 8427–8437, https://doi.org/10.5194/acp-13-8427-2013, https://doi.org/10.5194/acp-13-8427-2013, 2013
K. Laß, H. W. Bange, and G. Friedrichs
Biogeosciences, 10, 5325–5334, https://doi.org/10.5194/bg-10-5325-2013, https://doi.org/10.5194/bg-10-5325-2013, 2013
S. Walter, A. Kock, and T. Röckmann
Biogeosciences, 10, 3391–3403, https://doi.org/10.5194/bg-10-3391-2013, https://doi.org/10.5194/bg-10-3391-2013, 2013
C. Zindler, A. Bracher, C. A. Marandino, B. Taylor, E. Torrecilla, A. Kock, and H. W. Bange
Biogeosciences, 10, 3297–3311, https://doi.org/10.5194/bg-10-3297-2013, https://doi.org/10.5194/bg-10-3297-2013, 2013
W. Gülzow, G. Rehder, J. Schneider v. Deimling, T. Seifert, and Z. Tóth
Biogeosciences, 10, 81–99, https://doi.org/10.5194/bg-10-81-2013, https://doi.org/10.5194/bg-10-81-2013, 2013
B. W. Blomquist, C. W. Fairall, B. J. Huebert, and S. T. Wilson
Atmos. Meas. Tech., 5, 3069–3075, https://doi.org/10.5194/amt-5-3069-2012, https://doi.org/10.5194/amt-5-3069-2012, 2012
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
Biogeochemistry: Greenhouse Gases
Diel and seasonal methane dynamics in the shallow and turbulent Wadden Sea
Technical note: Skirt chamber – an open dynamic method for the rapid and minimally intrusive measurement of greenhouse gas emissions from peatlands
Seasonal variability of nitrous oxide concentrations and emissions in a temperate estuary
Reviews and syntheses: Recent advances in microwave remote sensing in support of terrestrial carbon cycle science in Arctic–boreal regions
Simulated methane emissions from Arctic ponds are highly sensitive to warming
Water-table-driven greenhouse gas emission estimates guide peatland restoration at national scale
Relationships between greenhouse gas production and landscape position during short-term permafrost thaw under anaerobic conditions in the Lena Delta
Carbon emissions and radiative forcings from tundra wildfires in the Yukon–Kuskokwim River Delta, Alaska
Carbon monoxide (CO) cycling in the Fram Strait, Arctic Ocean
Post-flooding disturbance recovery promotes carbon capture in riparian zones
Assessing CO2 and CH4 fluxes from mounds of African fungus-growing termites
Methane emissions due to reservoir flushing: a significant emission pathway?
Capabilities of optical and radar Earth observation data for up-scaling methane emissions linked to subsidence and permafrost degradation in sub-Arctic peatlands
Meteorological responses of carbon dioxide and methane fluxes in the terrestrial and aquatic ecosystems of a subarctic landscape
Herbivore-shrub interactions influence ecosystem respiration and BVOC composition in the subarctic
Spatial and temporal variability of methane emissions and environmental conditions in a hyper-eutrophic fishpond
Carbon emission and export from the Ket River, western Siberia
Evaluation of wetland CH4 in the Joint UK Land Environment Simulator (JULES) land surface model using satellite observations
Greenhouse gas fluxes in mangrove forest soil in an Amazon estuary
Temporal patterns and drivers of CO2 emission from dry sediments in a groyne field of a large river
Effects of water table level and nitrogen deposition on methane and nitrous oxide emissions in an alpine peatland
Highest methane concentrations in an Arctic river linked to local terrestrial inputs
Seasonal study of the small-scale variability in dissolved methane in the western Kiel Bight (Baltic Sea) during the European heatwave in 2018
Trace gas fluxes from tidal salt marsh soils: implications for carbon–sulfur biogeochemistry
Spatial and temporal variation in δ13C values of methane emitted from a hemiboreal mire: methanogenesis, methanotrophy, and hysteresis
Intercomparison of methods to estimate gross primary production based on CO2 and COS flux measurements
Lateral carbon export has low impact on the net ecosystem carbon balance of a polygonal tundra catchment
The effect of static chamber base on N2O flux in drip irrigation
Controls on autotrophic and heterotrophic respiration in an ombrotrophic bog
Episodic N2O emissions following tillage of a legume–grass cover crop mixture
Variation in CO2 and CH4 fluxes among land cover types in heterogeneous Arctic tundra in northeastern Siberia
Response of vegetation and carbon fluxes to brown lemming herbivory in northern Alaska
Sources of nitrous oxide and the fate of mineral nitrogen in subarctic permafrost peat soils
Data-based estimates of interannual sea–air CO2 flux variations 1957–2020 and their relation to environmental drivers
Evaluating alternative ebullition models for predicting peatland methane emission and its pathways via data–model fusion
Excess soil moisture and fresh carbon input are prerequisites for methane production in podzolic soil
Low biodegradability of particulate organic carbon mobilized from thaw slumps on the Peel Plateau, NT, and possible chemosynthesis and sorption effects
Grazing enhances carbon cycling but reduces methane emission during peak growing season in the Siberian Pleistocene Park tundra site
Ideas and perspectives: Enhancing research and monitoring of carbon pools and land-to-atmosphere greenhouse gases exchange in developing countries
Ignoring carbon emissions from thermokarst ponds results in overestimation of tundra net carbon uptake
Quantification of potential methane emissions associated with organic matter amendments following oxic-soil inundation
Assessing the spatial and temporal variability of greenhouse gas emissions from different configurations of on-site wastewater treatment system using discrete and continuous gas flux measurement
Dimethylated sulfur compounds in the Peruvian upwelling system
Partitioning carbon sources between wetland and well-drained ecosystems to a tropical first-order stream – implications for carbon cycling at the watershed scale (Nyong, Cameroon)
Extreme events driving year-to-year differences in gross primary productivity across the US
Methane gas emissions from savanna fires: what analysis of local burning regimes in a working West African landscape tell us
Methane in Zackenberg Valley, NE Greenland: multidecadal growing season fluxes of a high-Arctic tundra
Field-scale CH4 emission at a subarctic mire with heterogeneous permafrost thaw status
Evaluation of denitrification and decomposition from three biogeochemical models using laboratory measurements of N2, N2O and CO2
Temporal trends in methane emissions from a small eutrophic reservoir: the key role of a spring burst
Tim René de Groot, Anne Margriet Mol, Katherine Mesdag, Pierre Ramond, Rachel Ndhlovu, Julia Catherine Engelmann, Thomas Röckmann, and Helge Niemann
Biogeosciences, 20, 3857–3872, https://doi.org/10.5194/bg-20-3857-2023, https://doi.org/10.5194/bg-20-3857-2023, 2023
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This study investigates methane dynamics in the Wadden Sea. Our measurements revealed distinct variations triggered by seasonality and tidal forcing. The methane budget was higher in warmer seasons but surprisingly high in colder seasons. Methane dynamics were amplified during low tides, flushing the majority of methane into the North Sea or releasing it to the atmosphere. Methanotrophic activity was also elevated during low tide but mitigated only a small fraction of the methane efflux.
Frederic Thalasso, Brenda Riquelme, Andrés Gómez, Roy Mackenzie, Francisco Javier Aguirre, Jorge Hoyos-Santillan, Ricardo Rozzi, and Armando Sepulveda-Jauregui
Biogeosciences, 20, 3737–3749, https://doi.org/10.5194/bg-20-3737-2023, https://doi.org/10.5194/bg-20-3737-2023, 2023
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A robust skirt-chamber design to capture and quantify greenhouse gas emissions from peatlands is presented. Compared to standard methods, this design improves the spatial resolution of field studies in remote locations while minimizing intrusion.
Gesa Schulz, Tina Sanders, Yoana G. Voynova, Hermann W. Bange, and Kirstin Dähnke
Biogeosciences, 20, 3229–3247, https://doi.org/10.5194/bg-20-3229-2023, https://doi.org/10.5194/bg-20-3229-2023, 2023
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Nitrous oxide (N2O) is an important greenhouse gas. However, N2O emissions from estuaries underlie significant uncertainties due to limited data availability and high spatiotemporal variability. We found the Elbe Estuary (Germany) to be a year-round source of N2O, with the highest emissions in winter along with high nitrogen loads. However, in spring and summer, N2O emissions did not decrease alongside lower nitrogen loads because organic matter fueled in situ N2O production along the estuary.
Alex Mavrovic, Oliver Sonnentag, Juha Lemmetyinen, Jennifer L. Baltzer, Christophe Kinnard, and Alexandre Roy
Biogeosciences, 20, 2941–2970, https://doi.org/10.5194/bg-20-2941-2023, https://doi.org/10.5194/bg-20-2941-2023, 2023
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This review supports the integration of microwave spaceborne information into carbon cycle science for Arctic–boreal regions. The microwave data record spans multiple decades with frequent global observations of soil moisture and temperature, surface freeze–thaw cycles, vegetation water storage, snowpack properties, and land cover. This record holds substantial unexploited potential to better understand carbon cycle processes.
Zoé Rehder, Thomas Kleinen, Lars Kutzbach, Victor Stepanenko, Moritz Langer, and Victor Brovkin
Biogeosciences, 20, 2837–2855, https://doi.org/10.5194/bg-20-2837-2023, https://doi.org/10.5194/bg-20-2837-2023, 2023
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We use a new model to investigate how methane emissions from Arctic ponds change with warming. We find that emissions increase substantially. Under annual temperatures 5 °C above present temperatures, pond methane emissions are more than 3 times higher than now. Most of this increase is caused by an increase in plant productivity as plants provide the substrate microbes used to produce methane. We conclude that vegetation changes need to be included in predictions of pond methane emissions.
Julian Koch, Lars Elsgaard, Mogens H. Greve, Steen Gyldenkærne, Cecilie Hermansen, Gregor Levin, Shubiao Wu, and Simon Stisen
Biogeosciences, 20, 2387–2403, https://doi.org/10.5194/bg-20-2387-2023, https://doi.org/10.5194/bg-20-2387-2023, 2023
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Utilizing peatlands for agriculture leads to large emissions of greenhouse gases worldwide. The emissions are triggered by lowering the water table, which is a necessary step in order to make peatlands arable. Many countries aim at reducing their emissions by restoring peatlands, which can be achieved by stopping agricultural activities and thereby raising the water table. We estimate a total emission of 2.6 Mt CO2-eq for organic-rich peatlands in Denmark and a potential reduction of 77 %.
Mélissa Laurent, Matthias Fuchs, Tanja Herbst, Alexandra Runge, Susanne Liebner, and Claire C. Treat
Biogeosciences, 20, 2049–2064, https://doi.org/10.5194/bg-20-2049-2023, https://doi.org/10.5194/bg-20-2049-2023, 2023
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In this study we investigated the effect of different parameters (temperature, landscape position) on the production of greenhouse gases during a 1-year permafrost thaw experiment. For very similar carbon and nitrogen contents, our results show a strong heterogeneity in CH4 production, as well as in microbial abundance. According to our study, these differences are mainly due to the landscape position and the hydrological conditions established as a result of the topography.
Michael Moubarak, Seeta Sistla, Stefano Potter, Susan M. Natali, and Brendan M. Rogers
Biogeosciences, 20, 1537–1557, https://doi.org/10.5194/bg-20-1537-2023, https://doi.org/10.5194/bg-20-1537-2023, 2023
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Tundra wildfires are increasing in frequency and severity with climate change. We show using a combination of field measurements and computational modeling that tundra wildfires result in a positive feedback to climate change by emitting significant amounts of long-lived greenhouse gasses. With these effects, attention to tundra fires is necessary for mitigating climate change.
Hanna I. Campen, Damian L. Arévalo-Martínez, and Hermann W. Bange
Biogeosciences, 20, 1371–1379, https://doi.org/10.5194/bg-20-1371-2023, https://doi.org/10.5194/bg-20-1371-2023, 2023
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Carbon monoxide (CO) is a climate-relevant trace gas emitted from the ocean. However, oceanic CO cycling is understudied. Results from incubation experiments conducted in the Fram Strait (Arctic Ocean) indicated that (i) pH did not affect CO cycling and (ii) enhanced CO production and consumption were positively correlated with coloured dissolved organic matter and nitrate concentrations. This suggests microbial CO uptake to be the driving factor for CO cycling in the Arctic Ocean.
Yihong Zhu, Ruihua Liu, Huai Zhang, Shaoda Liu, Zhengfeng Zhang, Fei-Hai Yu, and Timothy G. Gregoire
Biogeosciences, 20, 1357–1370, https://doi.org/10.5194/bg-20-1357-2023, https://doi.org/10.5194/bg-20-1357-2023, 2023
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With global warming, the risk of flooding is rising, but the response of the carbon cycle of aquatic and associated riparian systems
to flooding is still unclear. Based on the data collected in the Lijiang, we found that flooding would lead to significant carbon emissions of fluvial areas and riparian areas during flooding, but carbon capture may happen after flooding. In the riparian areas, the surviving vegetation, especially clonal plants, played a vital role in this transformation.
Matti Räsänen, Risto Vesala, Petri Rönnholm, Laura Arppe, Petra Manninen, Markus Jylhä, Jouko Rikkinen, Petri Pellikka, and Janne Rinne
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-24, https://doi.org/10.5194/bg-2023-24, 2023
Revised manuscript accepted for BG
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Fungus-growing termites recycle large part of dead plant material in African savannas and are significant sources of greenhouse gases. We measured CO2 and CH4 fluxes from their mounds and surrounding soils at open and closed habitats. The fluxes scale with mound volume. The results show that emissions from mounds of fungus-growing termites are more stable than those from other termites. The soil fluxes around the mound are affected by the termite colonies up to 2 m distance from the mound.
Ole Lessmann, Jorge Encinas Fernández, Karla Martínez-Cruz, and Frank Peeters
EGUsphere, https://doi.org/10.5194/egusphere-2023-422, https://doi.org/10.5194/egusphere-2023-422, 2023
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In our study, we assess the significance of methane (CH4) emissions due to reservoir flushing. We generated a large dataset of CH4 pore water concentrations in a reservoir's sediment to resolve seasonal CH4 distributions in the sediment. Our results show that in the studied reservoir, CH4 emissions caused by one flushing operation can represent 7–14 % of the annual CH4 emissions and that timing and frequency of the flushing operations affect the amount of released CH4.
Sofie Sjogersten, Martha Ledger, Matthias Siewert, Betsabé de la Barreda-Bautista, Andrew Sowter, David Gee, Giles Foody, and Doreen S. Boyd
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-17, https://doi.org/10.5194/bg-2023-17, 2023
Revised manuscript accepted for BG
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Permafrost thaw in Arctic regions is increasing methane emissions but quantification is difficult given the large and remote areas impacted. We show that drone data together with satellite data can be used to extrapolate emissions across the wider landscape as well as detecting areas at risk of higher emissions. A transition of currently degrading areas to fen type vegetation can increase emission with several orders of magnitude highlighting the importance of quantifying areas at risk.
Lauri Heiskanen, Juha-Pekka Tuovinen, Henriikka Vekuri, Aleksi Räsänen, Tarmo Virtanen, Sari Juutinen, Annalea Lohila, Juha Mikola, and Mika Aurela
Biogeosciences, 20, 545–572, https://doi.org/10.5194/bg-20-545-2023, https://doi.org/10.5194/bg-20-545-2023, 2023
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We measured and modelled the CO2 and CH4 fluxes of the terrestrial and aquatic ecosystems of the subarctic landscape for 2 years. The landscape was an annual CO2 sink and a CH4 source. The forest had the largest contribution to the landscape-level CO2 sink and the peatland to the CH4 emissions. The lakes released 24 % of the annual net C uptake of the landscape back to the atmosphere. The C fluxes were affected most by the rainy peak growing season of 2017 and the drought event in July 2018.
Cole G. Brachmann, Tage Vowles, Riikka Rinnan, Mats P. Björkman, Anna Ekberg, and Robert G. Björk
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-14, https://doi.org/10.5194/bg-2023-14, 2023
Revised manuscript accepted for BG
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Herbivores change plant communities through grazing, altering the amount of CO2 and plant-specific chemicals (termed VOCs) emitted. We tested this effect by excluding herbivores and studying the CO2 and VOC emissions. Herbivores reduced CO2 emissions from a meadow community and altered VOC composition, however community type had the strongest effect on the amount of CO2 and VOCs released. Herbivores can mediate greenhouse gas emissions, but the effect is marginal and community dependent.
Petr Znachor, Jiří Nedoma, Vojtech Kolar, and Anna Matoušů
Biogeosciences Discuss., https://doi.org/10.5194/bg-2023-4, https://doi.org/10.5194/bg-2023-4, 2023
Revised manuscript accepted for BG
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We conducted intensive spatial sampling of the hypertrophic fishpond to better understand the spatial dynamics of methane fluxes and environmental heterogeneity in fishponds. The diffusive fluxes of methane accounted for only a minor fraction of the total fluxes, and both varied pronouncedly within the pond and over the studied summer season, which could be explained only by the water depth. Wind substantially affected temperature, oxygen and chlorophyll-a distribution in the pond.
Artem G. Lim, Ivan V. Krickov, Sergey N. Vorobyev, Mikhail A. Korets, Sergey Kopysov, Liudmila S. Shirokova, Jan Karlsson, and Oleg S. Pokrovsky
Biogeosciences, 19, 5859–5877, https://doi.org/10.5194/bg-19-5859-2022, https://doi.org/10.5194/bg-19-5859-2022, 2022
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In order to quantify C transport and emission and main environmental factors controlling the C cycle in Siberian rivers, we investigated the largest tributary of the Ob River, the Ket River basin, by measuring spatial and seasonal variations in carbon CO2 and CH4 concentrations and emissions together with hydrochemical analyses. The obtained results are useful for large-scale modeling of C emission and export fluxes from permafrost-free boreal rivers of an underrepresented region of the world.
Robert J. Parker, Chris Wilson, Edward Comyn-Platt, Garry Hayman, Toby R. Marthews, A. Anthony Bloom, Mark F. Lunt, Nicola Gedney, Simon J. Dadson, Joe McNorton, Neil Humpage, Hartmut Boesch, Martyn P. Chipperfield, Paul I. Palmer, and Dai Yamazaki
Biogeosciences, 19, 5779–5805, https://doi.org/10.5194/bg-19-5779-2022, https://doi.org/10.5194/bg-19-5779-2022, 2022
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Wetlands are the largest natural source of methane, one of the most important climate gases. The JULES land surface model simulates these emissions. We use satellite data to evaluate how well JULES reproduces the methane seasonal cycle over different tropical wetlands. It performs well for most regions; however, it struggles for some African wetlands influenced heavily by river flooding. We explain the reasons for these deficiencies and highlight how future development will improve these areas.
Saúl Edgardo Martínez Castellón, José Henrique Cattanio, José Francisco Berrêdo, Marcelo Rollnic, Maria de Lourdes Ruivo, and Carlos Noriega
Biogeosciences, 19, 5483–5497, https://doi.org/10.5194/bg-19-5483-2022, https://doi.org/10.5194/bg-19-5483-2022, 2022
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We seek to understand the influence of climatic seasonality and microtopography on CO2 and CH4 fluxes in an Amazonian mangrove. Topography and seasonality had a contrasting influence when comparing the two gas fluxes: CO2 fluxes were greater in high topography in the dry period, and CH4 fluxes were greater in the rainy season in low topography. Only CO2 fluxes were correlated with soil organic matter, the proportion of carbon and nitrogen, and redox potential.
Matthias Koschorreck, Klaus Holger Knorr, and Lelaina Teichert
Biogeosciences, 19, 5221–5236, https://doi.org/10.5194/bg-19-5221-2022, https://doi.org/10.5194/bg-19-5221-2022, 2022
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At low water levels, parts of the bottom of rivers fall dry. These beaches or mudflats emit the greenhouse gas carbon dioxide (CO2) to the atmosphere. We found that those emissions are caused by microbial reactions in the sediment and that they change with time. Emissions were influenced by many factors like temperature, water level, rain, plants, and light.
Wantong Zhang, Zhengyi Hu, Joachim Audet, Thomas A. Davidson, Enze Kang, Xiaoming Kang, Yong Li, Xiaodong Zhang, and Jinzhi Wang
Biogeosciences, 19, 5187–5197, https://doi.org/10.5194/bg-19-5187-2022, https://doi.org/10.5194/bg-19-5187-2022, 2022
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This work focused on the CH4 and N2O emissions from alpine peatlands in response to the interactive effects of altered water table levels and increased nitrogen deposition. Across the 2-year mesocosm experiment, nitrogen deposition showed nonlinear effects on CH4 emissions and linear effects on N2O emissions, and these N effects were associated with the water table levels. Our results imply the future scenario of strengthened CH4 and N2O emissions from an alpine peatland.
Karel Castro-Morales, Anna Canning, Sophie Arzberger, Will A. Overholt, Kirsten Küsel, Olaf Kolle, Mathias Göckede, Nikita Zimov, and Arne Körtzinger
Biogeosciences, 19, 5059–5077, https://doi.org/10.5194/bg-19-5059-2022, https://doi.org/10.5194/bg-19-5059-2022, 2022
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Permafrost thaw releases methane that can be emitted into the atmosphere or transported by Arctic rivers. Methane measurements are lacking in large Arctic river regions. In the Kolyma River (northeast Siberia), we measured dissolved methane to map its distribution with great spatial detail. The river’s edge and river junctions had the highest methane concentrations compared to other river areas. Microbial communities in the river showed that the river’s methane likely is from the adjacent land.
Sonja Gindorf, Hermann W. Bange, Dennis Booge, and Annette Kock
Biogeosciences, 19, 4993–5006, https://doi.org/10.5194/bg-19-4993-2022, https://doi.org/10.5194/bg-19-4993-2022, 2022
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Methane is a climate-relevant greenhouse gas which is emitted to the atmosphere from coastal areas such as the Baltic Sea. We measured the methane concentration in the water column of the western Kiel Bight. Methane concentrations were higher in September than in June. We found no relationship between the 2018 European heatwave and methane concentrations. Our results show that the methane distribution in the water column is strongly affected by temporal and spatial variabilities.
Margaret Capooci and Rodrigo Vargas
Biogeosciences, 19, 4655–4670, https://doi.org/10.5194/bg-19-4655-2022, https://doi.org/10.5194/bg-19-4655-2022, 2022
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Tidal salt marsh soil emits greenhouse gases, as well as sulfur-based gases, which play roles in global climate but are not well studied as they are difficult to measure. Traditional methods of measuring these gases worked relatively well for carbon dioxide, but less so for methane, nitrous oxide, carbon disulfide, and dimethylsulfide. High variability of trace gases complicates the ability to accurately calculate gas budgets and new approaches are needed for monitoring protocols.
Janne Rinne, Patryk Łakomiec, Patrik Vestin, Joel D. White, Per Weslien, Julia Kelly, Natascha Kljun, Lena Ström, and Leif Klemedtsson
Biogeosciences, 19, 4331–4349, https://doi.org/10.5194/bg-19-4331-2022, https://doi.org/10.5194/bg-19-4331-2022, 2022
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The study uses the stable isotope 13C of carbon in methane to investigate the origins of spatial and temporal variation in methane emitted by a temperate wetland ecosystem. The results indicate that methane production is more important for spatial variation than methane consumption by micro-organisms. Temporal variation on a seasonal timescale is most likely affected by more than one driver simultaneously.
Kukka-Maaria Kohonen, Roderick Dewar, Gianluca Tramontana, Aleksanteri Mauranen, Pasi Kolari, Linda M. J. Kooijmans, Dario Papale, Timo Vesala, and Ivan Mammarella
Biogeosciences, 19, 4067–4088, https://doi.org/10.5194/bg-19-4067-2022, https://doi.org/10.5194/bg-19-4067-2022, 2022
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Four different methods for quantifying photosynthesis (GPP) at ecosystem scale were tested, of which two are based on carbon dioxide (CO2) and two on carbonyl sulfide (COS) flux measurements. CO2-based methods are traditional partitioning, and a new method uses machine learning. We introduce a novel method for calculating GPP from COS fluxes, with potentially better applicability than the former methods. Both COS-based methods gave on average higher GPP estimates than the CO2-based estimates.
Lutz Beckebanze, Benjamin R. K. Runkle, Josefine Walz, Christian Wille, David Holl, Manuel Helbig, Julia Boike, Torsten Sachs, and Lars Kutzbach
Biogeosciences, 19, 3863–3876, https://doi.org/10.5194/bg-19-3863-2022, https://doi.org/10.5194/bg-19-3863-2022, 2022
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In this study, we present observations of lateral and vertical carbon fluxes from a permafrost-affected study site in the Russian Arctic. From this dataset we estimate the net ecosystem carbon balance for this study site. We show that lateral carbon export has a low impact on the net ecosystem carbon balance during the complete study period (3 months). Nevertheless, our results also show that lateral carbon export can exceed vertical carbon uptake at the beginning of the growing season.
Shahar Baram, Asher Bar-Tal, Alon Gal, Shmulik P. Friedman, and David Russo
Biogeosciences, 19, 3699–3711, https://doi.org/10.5194/bg-19-3699-2022, https://doi.org/10.5194/bg-19-3699-2022, 2022
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Static chambers are the most common tool used to measure greenhouse gas (GHG) fluxes. We tested the impact of such chambers on nitrous oxide emissions in drip irrigation. Field measurements and 3-D simulations show that the chamber base drastically affects the water and nutrient distribution in the soil and hence the measured GHG fluxes. A nomogram is suggested to determine the optimal diameter of a cylindrical chamber that ensures minimal disturbance.
Tracy E. Rankin, Nigel T. Roulet, and Tim R. Moore
Biogeosciences, 19, 3285–3303, https://doi.org/10.5194/bg-19-3285-2022, https://doi.org/10.5194/bg-19-3285-2022, 2022
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Peatland respiration is made up of plant and peat sources. How to separate these sources is not well known as peat respiration is not straightforward and is more influenced by vegetation dynamics than previously thought. Results of plot level measurements from shrubs and sparse grasses in a woody bog show that plants' respiration response to changes in climate is related to their different root structures, implying a difference in the mechanisms by which they obtain water resources.
Alison Bressler and Jennifer Blesh
Biogeosciences, 19, 3169–3184, https://doi.org/10.5194/bg-19-3169-2022, https://doi.org/10.5194/bg-19-3169-2022, 2022
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Our field experiment tested if a mixture of a nitrogen-fixing legume and non-legume cover crop could reduce nitrous oxide (N2O) emissions following tillage, compared to the legume grown alone. We found higher N2O following both legume treatments, compared to those without, and lower emissions from the cover crop mixture at one of the two test sites, suggesting that interactions between cover crop types and soil quality influence N2O emissions.
Sari Juutinen, Mika Aurela, Juha-Pekka Tuovinen, Viktor Ivakhov, Maiju Linkosalmi, Aleksi Räsänen, Tarmo Virtanen, Juha Mikola, Johanna Nyman, Emmi Vähä, Marina Loskutova, Alexander Makshtas, and Tuomas Laurila
Biogeosciences, 19, 3151–3167, https://doi.org/10.5194/bg-19-3151-2022, https://doi.org/10.5194/bg-19-3151-2022, 2022
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We measured CO2 and CH4 fluxes in heterogenous Arctic tundra in eastern Siberia. We found that tundra wetlands with sedge and grass vegetation contributed disproportionately to the landscape's ecosystem CO2 uptake and CH4 emissions to the atmosphere. Moreover, we observed high CH4 consumption in dry tundra, particularly in barren areas, offsetting part of the CH4 emissions from the wetlands.
Jessica Plein, Rulon W. Clark, Kyle A. Arndt, Walter C. Oechel, Douglas Stow, and Donatella Zona
Biogeosciences, 19, 2779–2794, https://doi.org/10.5194/bg-19-2779-2022, https://doi.org/10.5194/bg-19-2779-2022, 2022
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Tundra vegetation and the carbon balance of Arctic ecosystems can be substantially impacted by herbivory. We tested how herbivory by brown lemmings in individual enclosure plots have impacted carbon exchange of tundra ecosystems via altering carbon dioxide (CO2) and methane (CH4) fluxes. Lemmings significantly decreased net CO2 uptake while not affecting CH4 emissions. There was no significant difference in the subsequent growing season due to recovery of the vegetation.
Jenie Gil, Maija E. Marushchak, Tobias Rütting, Elizabeth M. Baggs, Tibisay Pérez, Alexander Novakovskiy, Tatiana Trubnikova, Dmitry Kaverin, Pertti J. Martikainen, and Christina Biasi
Biogeosciences, 19, 2683–2698, https://doi.org/10.5194/bg-19-2683-2022, https://doi.org/10.5194/bg-19-2683-2022, 2022
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N2O emissions from permafrost soils represent up to 11.6 % of total N2O emissions from natural soils, and their contribution to the global N2O budget will likely increase due to climate change. A better understanding of N2O production from permafrost soil is needed to evaluate the role of arctic ecosystems in the global N2O budget. By studying microbial N2O production processes in N2O hotspots in permafrost peatlands, we identified denitrification as the dominant source of N2O in these surfaces.
Christian Rödenbeck, Tim DeVries, Judith Hauck, Corinne Le Quéré, and Ralph F. Keeling
Biogeosciences, 19, 2627–2652, https://doi.org/10.5194/bg-19-2627-2022, https://doi.org/10.5194/bg-19-2627-2022, 2022
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The ocean is an important part of the global carbon cycle, taking up about a quarter of the anthropogenic CO2 emitted by burning of fossil fuels and thus slowing down climate change. However, the CO2 uptake by the ocean is, in turn, affected by variability and trends in climate. Here we use carbon measurements in the surface ocean to quantify the response of the oceanic CO2 exchange to environmental conditions and discuss possible mechanisms underlying this response.
Shuang Ma, Lifen Jiang, Rachel M. Wilson, Jeff P. Chanton, Scott Bridgham, Shuli Niu, Colleen M. Iversen, Avni Malhotra, Jiang Jiang, Xingjie Lu, Yuanyuan Huang, Jason Keller, Xiaofeng Xu, Daniel M. Ricciuto, Paul J. Hanson, and Yiqi Luo
Biogeosciences, 19, 2245–2262, https://doi.org/10.5194/bg-19-2245-2022, https://doi.org/10.5194/bg-19-2245-2022, 2022
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The relative ratio of wetland methane (CH4) emission pathways determines how much CH4 is oxidized before leaving the soil. We found an ebullition modeling approach that has a better performance in deep layer pore water CH4 concentration. We suggest using this approach in land surface models to accurately represent CH4 emission dynamics and response to climate change. Our results also highlight that both CH4 flux and belowground concentration data are important to constrain model parameters.
Mika Korkiakoski, Tiia Määttä, Krista Peltoniemi, Timo Penttilä, and Annalea Lohila
Biogeosciences, 19, 2025–2041, https://doi.org/10.5194/bg-19-2025-2022, https://doi.org/10.5194/bg-19-2025-2022, 2022
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We measured CH4 fluxes and production and oxidation potentials from irrigated and non-irrigated podzolic soil in a boreal forest. CH4 sink was smaller at the irrigated site but did not cause CH4 emission, with one exception. We also showed that under laboratory conditions, not only wet conditions, but also fresh carbon, are needed to make podzolic soil into a CH4 source. Our study provides important data for improving the process models describing the upland soil CH4 dynamics.
Sarah Shakil, Suzanne E. Tank, Jorien E. Vonk, and Scott Zolkos
Biogeosciences, 19, 1871–1890, https://doi.org/10.5194/bg-19-1871-2022, https://doi.org/10.5194/bg-19-1871-2022, 2022
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Permafrost thaw-driven landslides in the western Arctic are increasing organic carbon delivered to headwaters of drainage networks in the western Canadian Arctic by orders of magnitude. Through a series of laboratory experiments, we show that less than 10 % of this organic carbon is likely to be mineralized to greenhouse gases during transport in these networks. Rather most of the organic carbon is likely destined for burial and sequestration for centuries to millennia.
Wolfgang Fischer, Christoph K. Thomas, Nikita Zimov, and Mathias Göckede
Biogeosciences, 19, 1611–1633, https://doi.org/10.5194/bg-19-1611-2022, https://doi.org/10.5194/bg-19-1611-2022, 2022
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Arctic permafrost ecosystems may release large amounts of carbon under warmer future climates and may therefore accelerate global climate change. Our study investigated how long-term grazing by large animals influenced ecosystem characteristics and carbon budgets at a Siberian permafrost site. Our results demonstrate that such management can contribute to stabilizing ecosystems to keep carbon in the ground, particularly through drying soils and reducing methane emissions.
Dong-Gill Kim, Ben Bond-Lamberty, Youngryel Ryu, Bumsuk Seo, and Dario Papale
Biogeosciences, 19, 1435–1450, https://doi.org/10.5194/bg-19-1435-2022, https://doi.org/10.5194/bg-19-1435-2022, 2022
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As carbon (C) and greenhouse gas (GHG) research has adopted appropriate technology and approach (AT&A), low-cost instruments, open-source software, and participatory research and their results were well accepted by scientific communities. In terms of cost, feasibility, and performance, the integration of low-cost and low-technology, participatory and networking-based research approaches can be AT&A for enhancing C and GHG research in developing countries.
Lutz Beckebanze, Zoé Rehder, David Holl, Christian Wille, Charlotta Mirbach, and Lars Kutzbach
Biogeosciences, 19, 1225–1244, https://doi.org/10.5194/bg-19-1225-2022, https://doi.org/10.5194/bg-19-1225-2022, 2022
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Arctic permafrost landscapes feature many water bodies. In contrast to the terrestrial parts of the landscape, the water bodies release carbon to the atmosphere. We compare carbon dioxide and methane fluxes from small water bodies to the surrounding tundra and find not accounting for the carbon dioxide emissions leads to an overestimation of the tundra uptake by 11 %. Consequently, changes in hydrology and water body distribution may substantially impact the overall carbon budget of the Arctic.
Brian Scott, Andrew H. Baldwin, and Stephanie A. Yarwood
Biogeosciences, 19, 1151–1164, https://doi.org/10.5194/bg-19-1151-2022, https://doi.org/10.5194/bg-19-1151-2022, 2022
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Carbon dioxide and methane contribute to global warming. What can we do? We can build wetlands: they store carbon dioxide and should cause global cooling. But when first built they produce excess methane. Eventually built wetlands will cause cooling, but it may take decades or even centuries. How we build wetlands matters. We show that a common practice, using organic matter, such as manure, can make a big difference whether or not the wetlands we build start global cooling within our lifetime.
Jan Knappe, Celia Somlai, and Laurence W. Gill
Biogeosciences, 19, 1067–1085, https://doi.org/10.5194/bg-19-1067-2022, https://doi.org/10.5194/bg-19-1067-2022, 2022
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Two domestic on-site wastewater treatment systems have been monitored for greenhouse gas (carbon dioxide, methane and nitrous oxide) emissions coming from the process units, soil and vent pipes. This has enabled the net greenhouse gas per person to be quantified for the first time, as well as the impact of pre-treatment on the effluent before being discharged to soil. These decentralised wastewater treatment systems serve approx. 20 % of the population in both Europe and the United States.
Yanan Zhao, Dennis Booge, Christa A. Marandino, Cathleen Schlundt, Astrid Bracher, Elliot L. Atlas, Jonathan Williams, and Hermann W. Bange
Biogeosciences, 19, 701–714, https://doi.org/10.5194/bg-19-701-2022, https://doi.org/10.5194/bg-19-701-2022, 2022
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We present here, for the first time, simultaneously measured dimethylsulfide (DMS) seawater concentrations and DMS atmospheric mole fractions from the Peruvian upwelling region during two cruises in December 2012 and October 2015. Our results indicate low oceanic DMS concentrations and atmospheric DMS molar fractions in surface waters and the atmosphere, respectively. In addition, the Peruvian upwelling region was identified as an insignificant source of DMS emissions during both periods.
Moussa Moustapha, Loris Deirmendjian, David Sebag, Jean-Jacques Braun, Stéphane Audry, Henriette Ateba Bessa, Thierry Adatte, Carole Causserand, Ibrahima Adamou, Benjamin Ngounou Ngatcha, and Frédéric Guérin
Biogeosciences, 19, 137–163, https://doi.org/10.5194/bg-19-137-2022, https://doi.org/10.5194/bg-19-137-2022, 2022
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We monitor the spatio-temporal variability of organic and inorganic carbon (C) species in the tropical Nyong River (Cameroon), across groundwater and increasing stream orders. We show the significant contribution of wetland as a C source for tropical rivers. Thus, ignoring the river–wetland connectivity might lead to the misrepresentation of C dynamics in tropical watersheds. Finally, total fluvial carbon losses might offset ~10 % of the net C sink estimated for the whole Nyong watershed.
Alexander J. Turner, Philipp Köhler, Troy S. Magney, Christian Frankenberg, Inez Fung, and Ronald C. Cohen
Biogeosciences, 18, 6579–6588, https://doi.org/10.5194/bg-18-6579-2021, https://doi.org/10.5194/bg-18-6579-2021, 2021
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This work builds a high-resolution estimate (500 m) of gross primary productivity (GPP) over the US using satellite measurements of solar-induced chlorophyll fluorescence (SIF) from the TROPOspheric Monitoring Instrument (TROPOMI) between 2018 and 2020. We identify ecosystem-specific scaling factors for estimating gross primary productivity (GPP) from TROPOMI SIF. Extreme precipitation events drive four regional GPP anomalies that account for 28 % of year-to-year GPP differences across the US.
Paul Laris, Moussa Koné, Fadiala Dembélé, Christine M. Rodrigue, Lilian Yang, Rebecca Jacobs, and Quincy Laris
Biogeosciences, 18, 6229–6244, https://doi.org/10.5194/bg-18-6229-2021, https://doi.org/10.5194/bg-18-6229-2021, 2021
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Savanna fires play a key role in the global carbon cycle because they release methane. Although it burns the most, there are few studies from West Africa. We conducted 36 experimental fires according to local practice to collect smoke samples. We found that fires set early in the season had higher methane emissions than those set later, and head fires had double the emissions of backfires. We conclude policies to reduce emissions will not have the desired effects if fire type is not considered.
Johan H. Scheller, Mikhail Mastepanov, Hanne H. Christiansen, and Torben R. Christensen
Biogeosciences, 18, 6093–6114, https://doi.org/10.5194/bg-18-6093-2021, https://doi.org/10.5194/bg-18-6093-2021, 2021
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Our study presents a time series of methane emissions in a high-Arctic-tundra landscape over 14 summers, which shows large variations between years. The methane emissions from the valley are expected to more than double in the late 21st century. This warming increases permafrost thaw, which could increase surface erosion in the valley. Increased erosion could offset some of the rise in methane fluxes from the valley, but this would require large-scale impacts on vegetated surfaces.
Patryk Łakomiec, Jutta Holst, Thomas Friborg, Patrick Crill, Niklas Rakos, Natascha Kljun, Per-Ola Olsson, Lars Eklundh, Andreas Persson, and Janne Rinne
Biogeosciences, 18, 5811–5830, https://doi.org/10.5194/bg-18-5811-2021, https://doi.org/10.5194/bg-18-5811-2021, 2021
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Methane emission from the subarctic mire with heterogeneous permafrost status was measured for the years 2014–2016. Lower methane emission was measured from the palsa mire sector while the thawing wet sector emitted more. Both sectors have a similar annual pattern with a gentle rise during spring and a decrease during autumn. The highest emission was observed in the late summer. Winter emissions were positive during the measurement period and have a significant impact on the annual budgets.
Balázs Grosz, Reinhard Well, Rene Dechow, Jan Reent Köster, Mohammad Ibrahim Khalil, Simone Merl, Andreas Rode, Bianca Ziehmer, Amanda Matson, and Hongxing He
Biogeosciences, 18, 5681–5697, https://doi.org/10.5194/bg-18-5681-2021, https://doi.org/10.5194/bg-18-5681-2021, 2021
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To assure quality predictions biogeochemical models must be current. We use data measured using novel incubation methods to test the denitrification sub-modules of three models. We aim to identify limitations in the denitrification modeling to inform next steps for development. Several areas are identified, most urgently improved denitrification control parameters and further testing with high-temporal-resolution datasets. Addressing these would significantly improve denitrification modeling.
Sarah Waldo, Jake J. Beaulieu, William Barnett, D. Adam Balz, Michael J. Vanni, Tanner Williamson, and John T. Walker
Biogeosciences, 18, 5291–5311, https://doi.org/10.5194/bg-18-5291-2021, https://doi.org/10.5194/bg-18-5291-2021, 2021
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Human-made reservoirs impact the carbon cycle. In particular, the breakdown of organic matter in reservoir sediments can result in large emissions of greenhouse gases (especially methane) to the atmosphere. This study takes an intensive look at the patterns in greenhouse gas emissions from a single reservoir in Ohio (United States) and the role of water temperature, precipitation, and algal blooms in emissions. We saw a "spring burst" of elevated emissions that challenged our assumptions.
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Short summary
To determine the variability between independent measurements of dissolved methane and nitrous oxide, seawater samples were analyzed by multiple laboratories. The results revealed the influences of the different parts of the analytical process, from the initial sample collection to the calculation of the final concentrations. Recommendations are made to improve dissolved methane and nitrous oxide measurements to help preclude future analytical discrepancies between laboratories.
To determine the variability between independent measurements of dissolved methane and nitrous...
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