Articles | Volume 18, issue 12
https://doi.org/10.5194/bg-18-3961-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/bg-18-3961-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
01 Jul 2021
Research article |
| 01 Jul 2021
| 01 Jul 2021
Methane in the Danube Delta: the importance of spatial patterns and diel cycles for atmospheric emission estimates
GEOMAR Helmholtz-Zentrum für Ozeanforschung, Kiel, Schleswig-Holstein, Germany
Bernhard Wehrli
Institute of Biogeochemistry and Pollutant Dynamics, ETH Zürich, Zurich, 8092, Switzerland
Eawag, Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, 6047, Switzerland
Arne Körtzinger
GEOMAR Helmholtz-Zentrum für Ozeanforschung, Kiel, Schleswig-Holstein, Germany
Christian-Albrechts-Universität zu Kiel, Kiel, Schleswig-Holstein, Germany
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EGUsphere, https://doi.org/10.5194/egusphere-2025-347, https://doi.org/10.5194/egusphere-2025-347, 2025
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Mesoscale eddies are suggested to enhance deep-sea carbon export, but quantifying carbon flux in these eddies remains challenging. This study combines in-situ camera particle profiles, carbon flux data, particle settling velocities, and respiration rates, while accounting for water temperature and oxygen concentration. Applied to Cape Verde's cyclonic eddies, it revealed a funnel-shaped flux pattern with doubled flux at the eddy core, highlighting their regional carbon sequestration impacts.
Nico Lange, Björn Fiedler, Marta Álvarez, Alice Benoit-Cattin, Heather Benway, Pier Luigi Buttigieg, Laurent Coppola, Kim Currie, Susana Flecha, Dana S. Gerlach, Makio Honda, I. Emma Huertas, Siv K. Lauvset, Frank Muller-Karger, Arne Körtzinger, Kevin M. O'Brien, Sólveig R. Ólafsdóttir, Fernando C. Pacheco, Digna Rueda-Roa, Ingunn Skjelvan, Masahide Wakita, Angelicque White, and Toste Tanhua
Earth Syst. Sci. Data, 16, 1901–1931, https://doi.org/10.5194/essd-16-1901-2024, https://doi.org/10.5194/essd-16-1901-2024, 2024
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The Synthesis Product for Ocean Time Series (SPOTS) is a novel achievement expanding and complementing the biogeochemical data landscape by providing consistent and high-quality biogeochemical time-series data from 12 ship-based fixed time-series programs. SPOTS covers multiple unique marine environments and time-series ranges, including data from 1983 to 2021. All in all, it facilitates a variety of applications that benefit from the collective value of biogeochemical time-series observations.
Cathy Wimart-Rousseau, Tobias Steinhoff, Birgit Klein, Henry Bittig, and Arne Körtzinger
Biogeosciences, 21, 1191–1211, https://doi.org/10.5194/bg-21-1191-2024, https://doi.org/10.5194/bg-21-1191-2024, 2024
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The marine CO2 system can be measured independently and continuously by BGC-Argo floats since numerous pH sensors have been developed to suit these autonomous measurements platforms. By applying the Argo correction routines to float pH data acquired in the subpolar North Atlantic Ocean, we report the uncertainty and lack of objective criteria associated with the choice of the reference method as well the reference depth for the pH correction.
Louise C. V. Rewrie, Burkard Baschek, Justus E. E. van Beusekom, Arne Körtzinger, Gregor Ollesch, and Yoana G. Voynova
Biogeosciences, 20, 4931–4947, https://doi.org/10.5194/bg-20-4931-2023, https://doi.org/10.5194/bg-20-4931-2023, 2023
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After heavy pollution in the 1980s, a long-term inorganic carbon increase in the Elbe Estuary (1997–2020) was fueled by phytoplankton and organic carbon production in the upper estuary, associated with improved water quality. A recent drought (2014–2020) modulated the trend, extending the water residence time and the dry summer season into May. The drought enhanced production of inorganic carbon in the estuary but significantly decreased the annual inorganic carbon export to coastal waters.
Pierre Friedlingstein, Michael O'Sullivan, Matthew W. Jones, Robbie M. Andrew, Dorothee C. E. Bakker, Judith Hauck, Peter Landschützer, Corinne Le Quéré, Ingrid T. Luijkx, Glen P. Peters, Wouter Peters, Julia Pongratz, Clemens Schwingshackl, Stephen Sitch, Josep G. Canadell, Philippe Ciais, Robert B. Jackson, Simone R. Alin, Peter Anthoni, Leticia Barbero, Nicholas R. Bates, Meike Becker, Nicolas Bellouin, Bertrand Decharme, Laurent Bopp, Ida Bagus Mandhara Brasika, Patricia Cadule, Matthew A. Chamberlain, Naveen Chandra, Thi-Tuyet-Trang Chau, Frédéric Chevallier, Louise P. Chini, Margot Cronin, Xinyu Dou, Kazutaka Enyo, Wiley Evans, Stefanie Falk, Richard A. Feely, Liang Feng, Daniel J. Ford, Thomas Gasser, Josefine Ghattas, Thanos Gkritzalis, Giacomo Grassi, Luke Gregor, Nicolas Gruber, Özgür Gürses, Ian Harris, Matthew Hefner, Jens Heinke, Richard A. Houghton, George C. Hurtt, Yosuke Iida, Tatiana Ilyina, Andrew R. Jacobson, Atul Jain, Tereza Jarníková, Annika Jersild, Fei Jiang, Zhe Jin, Fortunat Joos, Etsushi Kato, Ralph F. Keeling, Daniel Kennedy, Kees Klein Goldewijk, Jürgen Knauer, Jan Ivar Korsbakken, Arne Körtzinger, Xin Lan, Nathalie Lefèvre, Hongmei Li, Junjie Liu, Zhiqiang Liu, Lei Ma, Greg Marland, Nicolas Mayot, Patrick C. McGuire, Galen A. McKinley, Gesa Meyer, Eric J. Morgan, David R. Munro, Shin-Ichiro Nakaoka, Yosuke Niwa, Kevin M. O'Brien, Are Olsen, Abdirahman M. Omar, Tsuneo Ono, Melf Paulsen, Denis Pierrot, Katie Pocock, Benjamin Poulter, Carter M. Powis, Gregor Rehder, Laure Resplandy, Eddy Robertson, Christian Rödenbeck, Thais M. Rosan, Jörg Schwinger, Roland Séférian, T. Luke Smallman, Stephen M. Smith, Reinel Sospedra-Alfonso, Qing Sun, Adrienne J. Sutton, Colm Sweeney, Shintaro Takao, Pieter P. Tans, Hanqin Tian, Bronte Tilbrook, Hiroyuki Tsujino, Francesco Tubiello, Guido R. van der Werf, Erik van Ooijen, Rik Wanninkhof, Michio Watanabe, Cathy Wimart-Rousseau, Dongxu Yang, Xiaojuan Yang, Wenping Yuan, Xu Yue, Sönke Zaehle, Jiye Zeng, and Bo Zheng
Earth Syst. Sci. Data, 15, 5301–5369, https://doi.org/10.5194/essd-15-5301-2023, https://doi.org/10.5194/essd-15-5301-2023, 2023
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The Global Carbon Budget 2023 describes the methodology, main results, and data sets used to quantify the anthropogenic emissions of carbon dioxide (CO2) and their partitioning among the atmosphere, land ecosystems, and the ocean over the historical period (1750–2023). These living datasets are updated every year to provide the highest transparency and traceability in the reporting of CO2, the key driver of climate change.
R. Scott Winton, Silvia López-Casas, Daniel Valencia-Rodríguez, Camilo Bernal-Forero, Juliana Delgado, Bernhard Wehrli, and Luz Jiménez-Segura
Hydrol. Earth Syst. Sci., 27, 1493–1505, https://doi.org/10.5194/hess-27-1493-2023, https://doi.org/10.5194/hess-27-1493-2023, 2023
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Dams are an important and rapidly growing means of energy generation in the Tropical Andes of South America. To assess the impacts of dams in the region, we assessed differences in the upstream and downstream water quality of all hydropower dams in Colombia. We found evidence of substantial dam-induced changes in water temperature, dissolved oxygen concentration and suspended sediments. Dam-induced changes in Colombian waters violate regulations and are likely impacting aquatic life.
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.
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.
Gerhard Fischer, Oscar E. Romero, Johannes Karstensen, Karl-Heinz Baumann, Nasrollah Moradi, Morten Iversen, Götz Ruhland, Marco Klann, and Arne Körtzinger
Biogeosciences, 18, 6479–6500, https://doi.org/10.5194/bg-18-6479-2021, https://doi.org/10.5194/bg-18-6479-2021, 2021
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Low-oxygen eddies in the eastern subtropical North Atlantic can form an oasis for phytoplankton growth. Here we report on particle flux dynamics at the oligotrophic Cape Verde Ocean Observatory. We observed consistent flux patterns during the passages of low-oxygen eddies. We found distinct flux peaks in late winter, clearly exceeding background fluxes. Our findings suggest that the low-oxygen eddies sequester higher organic carbon than expected for oligotrophic settings.
Sigrid van Grinsven, Kirsten Oswald, Bernhard Wehrli, Corinne Jegge, Jakob Zopfi, Moritz F. Lehmann, and Carsten J. Schubert
Biogeosciences, 18, 3087–3101, https://doi.org/10.5194/bg-18-3087-2021, https://doi.org/10.5194/bg-18-3087-2021, 2021
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Lake Lovojärvi is a nutrient-rich lake with high amounts of methane at the bottom, but little near the top. Methane comes from the sediment and rises up through the water but is consumed by microorganisms along the way. They use oxygen if available, but in deeper water layers, no oxygen was present. There, nitrite, iron and humic substances were used, besides a collaboration between photosynthetic organisms and methane consumers, in which the first produced oxygen for the latter.
Cited articles
Abril, G. and Borges, A. V. (Eds.): Carbon dioxide and methane emissions from estuaries, in: Greenhouse gas emissions – fluxes and processes, Springer, Berlin, Heidelberg, Germany, 187–207, https://doi.org/10.1007/978-3-540-26643-3_8, 2005.
Abril, G. and Borges, A. V.: Ideas and perspectives: Carbon leaks from flooded land: do we need to replumb the inland water active pipe?, Biogeosciences, 16, 769–784, https://doi.org/10.5194/bg-16-769-2019, 2019.
Bange, H. W., Sim, C. H., Bastian, D., Kallert, J., Kock, A., Mujahid, A., and Müller, M.: Nitrous oxide (N2O) and methane (CH4) in rivers and estuaries of northwestern Borneo, Biogeosciences, 16, 4321–4335, https://doi.org/10.5194/bg-16-4321-2019, 2019.
Bastviken, D., Cole, J. J., Pace, M. L., and Van de-Bogert, M. C.: Fates of methane from different lake habitats: Connecting whole-lake budgets and CH4 emissions, J. Geophys. Res.-Biogeo., 113, G02024, https://doi.org/10.1029/2007JG000608, 2008.
Bastviken, D., Tranvik, L. J., Downing, J. A., Crill, P. M., and Enrich-Prast, A.: Freshwater methane emissions offset the continental carbon sink, Science, 331, p. 50, https://doi.org/10.1126/science.1196808, 2011.
Bartosiewicz, M., Przytulska, A., Lapierre, J. F., Laurion, I., Lehmann, M. F., and Maranger, R.: Hot tops, cold bottoms: Synergistic climate warming and shielding effects increase carbon burial in lakes, Limnol. Oceanogr., 4, 132–144, https://doi.org/10.1002/lol2.10117, 2019.
Bittig, H. C., Körtzinger, A., Neill, C., van Ooijen, E., Plant, J. N., Hahn, J., Johnson, K. S., Yang, B., and Emerson, S. R.: Oxygen Optode Sensors: Principle, Characterization, Calibration, and Application in the Ocean, Front. Mar. Sci., 4, 429, https://doi.org/10.3389/fmars.2017.00429, 2018.
Bižić, M., Klintzsch, T., Ionescu, D., Hindiyeh, M.Y., Günthel, M., Muro-Pastor, A.M., Eckert, W., Urich, T., Keppler, F. and Grossart, H.P.: Aquatic and terrestrial cyanobacteria produce methane, Science Advances, 6, eaax5343, https://doi.org/10.1126/sciadv.aax5343, 2020.
Bižić-Ionescu, M., Ionescu, D., Günthel, M., Tang, K. W., and Grossart, H. P.: Oxic Methane Cycling: New Evidence for Methane Formation in Oxic Lake Water, in: Biogenesis of Hydrocarbons, Handbook of Hydrocarbon and Lipid Microbiology, edited by: Stams, A. and Sousa, D., Springer, Cham, Switzerland, 379–400, https://doi.org/10.1007/978-3-319-78108-2_10, 2019.
Bogard, M. J., Del Giorgio, P. A., Boutet, L., Chaves, M. C. G., Prairie, Y. T., Merante, A., and Derry, A. M.: Oxic water column methanogenesis as a major component of aquatic CH4 fluxes, Nat. Commun., 5, 5350, https://doi.org/10.1038/ncomms6350, 2014.
Borges, A. V., Delille, B., Schiettecatte, L. S., Gazeau, F., Abril, G., and Frankignoulle, M.: Gas transfer velocities of CO2 in three European estuaries (Randers Fjord, Scheldt and Thames), Limnol. Oceanogr., 49, 1630–1641, 2004.
Borges, A. V., Darchambeau, F., Teodoru, C. R., Marwick, T. R., Tamooh, F., Geeraert, N., Omengo, F. O., Guérin, F., Lambert, T., Morana, C., and Okuku, E.: Globally significant greenhouse-gas emissions from African inland waters, Nat. Geosci., 8, 637–642, https://doi.org/10.1038/ngeo2486, 2015.
Bouillon, S., Dehairs, F., Schiettecatte, L. S., and Borges, A. V.: Biogeochemistry of the Tana estuary and delta (northern Kenya), Limnol. Oceanogr., 52, 46–59, 2007.
Canning, A. and Maier, M.-S.: Seasonal high-resolution sensor data for pCO2, pCH4, O2 and temperature/salinity within the Danube Delta, Romania in May 2017 [data set], PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.925080 (last access: 9 May 2021), 2020.
Canning, A. R., Fietzek, P., Rehder, G., and Körtzinger, A.: Technical note: Seamless gas measurements across the land–ocean aquatic continuum – corrections and evaluation of sensor data for CO2, CH4 and O2 from field deployments in contrasting environments, Biogeosciences, 18, 1351–1373, https://doi.org/10.5194/bg-18-1351-2021, 2021.
Cole, J. J. and Caraco, N. F.: Atmospheric exchange of carbon dioxide in a low-wind oligotrophic lake measured by the addition of SF6, Limnol. Oceanogr., 43, 647–656, https://doi.org/10.4319/lo.1998.43.4.0647, 1998.
Cole, J. J., Prairie, Y. T., Caraco, N. F., McDowell, W. H., Tranvik, L. J., Striegl, R. G., Duarte, C. M., Kortelainen, P., Downing, J. A., Middelburg, J. J., and Melack, J.: Plumbing the Global Carbon Cycle: Integrating Inland Waters into the Terrestrial Carbon Budget, Ecosystems, 10, 172–185, https://doi.org/10.1007/s10021-006-9013-8, 2007.
Crawford, J. T., Lottig, N. R., Stanley, E. H., Walker, J. F., Hanson, P. C., Finlay, J. C., and Striegl, R. G.: CO2 and CH4 emissions from streams in a lake-rich landscape: Patterns, controls, and regional significance, Global Biogeochem. Cy., 28, 197–210, https://doi.org/10.1002/2013GB004661, 2014a.
Crawford, J. T., Stanley, E. H., Spawn, S. A., Finlay, J. C., Loken, L. C., and Striegl, R. G.: Ebullitive methane emissions from oxygenated wetland streams, Global Change Biol., 20, 3408–3422, https://doi.org/10.1111/gcb.12614, 2014b.
Crawford, J. T., Loken, L. C., West, W. E., Crary, B., Spawn, S. A., Gubbins, N., Jones, S. E., Striegl, R. G., and Stanley, E. H.: Spatial heterogeneity of within-stream methane concentrations, J. Geophys. Res.-Biogeo., 122, 1036–1048, https://doi.org/10.1002/2016JG003698, 2017.
Cristofor, S., Vadineanu, A., and Ignat, G.: Importance of flood zones for nitrogen and phosphorus dynamics in the Danube Delta, Hydrobiologia, 251, 143–148, https://doi.org/10.1007/BF00007174, 1993.
Crusius, J. and Wanninkhof, R.: Gas transfer velocities measured at low wind speed over a lake, Limnol. Oceanogr., 48, 1010–1017, https://doi.org/10.4319/lo.2003.48.3.1010, 2003.
Cuna, S., Pendall, E., Miller, J. B., Tans, P. P., Dlugokencky, E., and White, J. W.: Separating contributions from natural and anthropogenic sources in atmospheric methane from the Black Sea region, Romania, Appl. Geochem., 23, 2871–2879, https://doi.org/10.1016/ j.apgeochem.2008.04.019, 2008.
Cunada, C. L., Lesack, L. F. W., and Tank, S. E.: Seasonal Dynamics of Dissolved Methane in Lakes of the Mackenzie Delta and the Role of Carbon Substrate Quality, J. Geophys. Res.-Biogeo., 123, 591–609, https://doi.org/10.1002/2017JG004047, 2018.
Davidson, T. A., Audet, J., Jeppesen, E., Landkildehus, F., Lauridsen, T. L., Søndergaard, M., and Syväranta, J.: Synergy between nutrients and warming enhances methane ebullition from experimental lakes, Nat. Clim. Change, 8, 156–160, https://doi.org/10.1038/s41558-017-0063-z, 2018.
Dean, J. F., Middelburg, J. J., Röckmann, T., Aerts, R., Blauw, L. G., Egger, M., Jetten, M. S., de Jong, A. E., Meisel, O. H., Rasigraf, O., and Slomp, C. P.: Methane Feedbacks to the Global Climate System in a Warmer World, Rev. Geophys., 56, 207–250, https://doi.org/10.1002/2017RG000559, 2018.
DelSontro, T., Mcginnis, D. F., Wehrli, B., and Ostrovsky, I.: Size does matter: Importance of large bubbles and small-scale hot spots for methane transport, Environ. Sci. Technol., 49, 1268–1276, https://doi.org/10.1021/es5054286, 2015.
DelSontro, T., del Giorgio, P. A., and Prairie, Y. T.: No Longer a Paradox: The Interaction Between Physical Transport and Biological Processes Explains the Spatial Distribution of Surface Water Methane Within and Across Lakes, Ecosystems, 21, 1073–1087, https://doi.org/10.1007/s10021-017-0205-1, 2018.
Dlugokencky, E.: NOAA/ESRL: available at: https://gml.noaa.gov/ccgg/trends_ch4/, last access: 12 December 2019.
Duc, N. T., Crill, P., and Bastviken, D.: Implications of temperature and sediment characteristics on methane formation and oxidation in lake sediments, Biogeochemistry, 100, 185–196, https://doi.org/10.1007/s10533-010-9415-8, 2010.
Durisch-Kaiser, E., Pavel, A., Doberer, A., Reutimann, J., Balan, S., Sobek, S., Radan, S., and Wehrli, B.: Nutrient retention, total N and P export and greenhouse gas emission from the Danube Delta lakes, GeoEcoMarina, 14, 81–90, 2008.
Enache, I., Florescu, L. I., Moldoveanu, M., Moza, M. I., Parpală, L., Sandu, C., Turko, P., Rîșnoveanu, G., and Spaak, P.: Diversity and distribution of Daphnia across space and time in Danube Delta lakes explained by food quality and abundance, Hydrobiologia, 842, 39–54, https://doi.org/10.1007/s10750-019-04025-y, 2019.
Fuchs, A., Lyautey, E., Montuelle, B., and Casper, P.: Effects of increasing temperatures on methane concentrations and methanogenesis during experimental incubation of sediments from oligotrophic and mesotrophic lakes,
J. Geophys. Res.-Biogeo., 121, 1394–1406, https://doi.org/10.1002/2016JG003328, 2016.
Galatchi, L. D. and Tudor, M.: Europe as a source of pollution – the main factor for the eutrophication of the Danube Delta and Black Sea, in: Chemicals as Intentional and Accidental Global Environmental Threats, Springer, Dordrecht, The Netherlands, 57–63, 2006.
Gatland, J. R., Santos, I. R., Maher, D. T., Duncan, T. M., and Erler, D. V.: Carbon dioxide and methane emissions from an artificially drained coastal wetland during a flood: Implications for wetland global warming potential, J. Geophys. Res.-Biogeo., 119, 1698–1716, https://doi.org/10.1002/2013JG002544, 2014.
Grasset, C., Abril, G., Mendonça, R., Roland, F., and Sobek, S.: The transformation of macrophyte-derived organic matter to methane relates to plant water and nutrient contents, Limnol. Oceanogr., 64, 1737–1749, https://doi.org/10.1002/lno.11148, 2019.
Guérin, F., Abril, G., Serça, D., Delon, C., Richard, S., Delmas, R., Tremblay, A., and Varfalvy, L.: Gas transfer velocities of CO2 and CH4 in a tropical reservoir and its river downstream,
J. Marine Syst., 66, 161–172, https://doi.org/10.1016/j.jmarsys.2006.03.019, 2007.
Harvey, F. E., Lee, D. R., Rudolph, D. L., and Frape, S. K.: Locating groundwater discharge in large lakes using bottom sediment electrical conductivity mapping, Water Resour. Res., 33, 2609–2615, 1997.
Jähne, B., Münnich, K. O., Bösinger, R., Dutzi, A., Huber, W., and Libner, P.: On the parameters influencing air-water gas exchange, J. Geophys. Res.-Oceans, 92, 1937–1949, https://doi.org/10.1029/JC092iC02p01937, 1987.
Joesoef, A., Kirchman, D. L., Sommerfield, C. K., and Cai, W.-J.: Seasonal variability of the inorganic carbon system in a large coastal plain estuary, Biogeosciences, 14, 4949–4963, https://doi.org/10.5194/bg-14-4949-2017, 2017.
Kasprak, A., Hough-Snee, N., Beechie, T., Bouwes, N., Brierley, G., Camp, R., Fryirs, K., Imaki, H., Jensen, M., O’Brien, G., Rosgen, D., and Wheaton, J.: The blurred line between form and process: a comparison of stream channel classification frameworks, PLoS One, 11, e0150293, https://doi.org/10.1371/journal.pone.0150293, 2016.
Maher, D. T., Cowley, K., Santos, I. R., Macklin, P., and Eyre, B. D.: Methane and carbon dioxide dynamics in a subtropical estuary over a diel cycle: Insights from automated in situ radioactive and stable isotope measurements, Mar. Chem., 168, 69–79, https://doi.org/10.1016/j.marchem.2014.10.017, 2015.
Maier, M.-S., Teodoru, C. R., and Wehrli, B.: Spatio-temporal variations in lateral and atmospheric carbon fluxes from the Danube Delta, Biogeosciences, 18, 1417–1437, https://doi.org/10.5194/bg-18-1417-2021, 2021.
Marín-Muñiz, J. L., Hernández, M. E., and Moreno-Casasola, P.: Greenhouse gas emissions from coastal freshwater wetlands in Veracruz Mexico: Effect of plant community and seasonal dynamics, Atmos. Environ., 107, 107–117, https://doi.org/10.1016/j.atmosenv.2015.02.036, 2015.
Marotta, H., Pinho, L., Bastviken, D., Tranvik, L. J., and Enrich-Prast, A.: Greenhouse gas production in low-latitude lake sediments responds strongly to warming, Nat. Clim. Change, 4, 467–470, https://doi.org/10.1038/nclimate2222, 2014.
McGinnis, D. F., Bilsley, N., Schmidt, M., Fietzek, P., Bodmer, P., Premke, K., Lorke, A., and Flury, S.: Deconstructing Methane Emissions from a Small Northern European River: Hydrodynamics and Temperature as Key Drivers, Environ. Sci. Technol., 50, 11680–11687, https://doi.org/10.1021/acs.est.6b03268, 2016.
Melack, J. M., Hess, L. L., Gastil, M., Forsberg, B. R., Hamilton, S. K., Lima, I. B., and Novo, E. M.: Regionalization of methane emissions in the Amazon Basin with microwave remote sensing, Global Change Biol., 10, 530–544, https://doi.org/10.1111/j.1529-8817.2003.00763.x, 2004.
Melton, J. R., Wania, R., Hodson, E. L., Poulter, B., Ringeval, B., Spahni, R., Bohn, T., Avis, C. A., Beerling, D. J., Chen, G., Eliseev, A. V., Denisov, S. N., Hopcroft, P. O., Lettenmaier, D. P., Riley, W. J., Singarayer, J. S., Subin, Z. M., Tian, H., Zürcher, S., Brovkin, V., van Bodegom, P. M., Kleinen, T., Yu, Z. C., and Kaplan, J. O.: Present state of global wetland extent and wetland methane modelling: conclusions from a model inter-comparison project (WETCHIMP), Biogeosciences, 10, 753–788, https://doi.org/10.5194/bg-10-753-2013, 2013.
Mendonca, R., Kosten, S., Sobek, S., Barros, N., Cole, J. J., Tranvik, L., and Roland, F.: Hydroelectric carbon sequestration, Nat. Geosci., 5, 838–840, https://doi.org/10.1038/ngeo1653, 2012.
Milberg, P., Törnqvist, L., Westerberg, L. M., and Bastviken, D.: Temporal variations in methane emissions from emergent aquatic macrophytes in two boreonemoral lakes, AOB Plants, 9, https://doi.org/10.1093/aobpla/plx029, 2017.
Myhre, G., Shindell, D., Breìon, F. M., Collins, W., Fuglestvedt, J., Huang, J., Koch, D., Lamarque, J. F., Lee, D., Mendoza, B., Nakajima, T., Robock, A., Stephens, G., Takemura, T., and Zhang, H.: Anthropogenic and Natural Radiative Forcing, in: Climate Change 2013: The Physical Science Basis, Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Stocker, T. F., Qin, D., Plattner, G.-K., Tignor, M., Allen, S. K., Boschung, J., Nauels, A., Xia, Y., Bex, V., and Midgley, P. M., Cambridge University Press, Cambridge, UK, New York, USA, 659–740, 2013.
Natchimuthu, S., Wallin, M. B., Klemedtsson, L., and Bastviken, D.: Spatio-temporal patterns of stream methane and carbon dioxide emissions in a hemiboreal catchment in Southwest Sweden, Sci. Rep.-UK, 7, 39729, https://doi.org/10.1038/srep39729, 2017.
Nimick, D. A., Gammons, C. H., and Parker, S. R.: Diel biogeochemical processes and their effect on the aqueous chemistry of streams: A review, Chem. Geol., 283, 3–17, https://doi.org/10.1016/j.chemgeo.2010.08.017, 2011.
Nisbet, E. G., Manning, M. R., Dlugokencky, E. J., Fisher, R. E., Lowry, D., Michel, S. E., Myhre, C. L., Platt, S. M., Allen, G., Bousquet, P., and Brownlow, R.: Very Strong Atmospheric Methane Growth in the 4 Years 2014–2017: Implications for the Paris Agreement, Global Biogeochem. Cy., 33, 318–342, https://doi.org/10.1029/2018GB006009, 2019.
Olsson, L., Ye, S., Yu, X., Wei, M., Krauss, K. W., and Brix, H.: Factors influencing CO2 and CH4 emissions from coastal wetlands in the Liaohe Delta, Northeast China, Biogeosciences, 12, 4965–4977, https://doi.org/10.5194/bg-12-4965-2015, 2015.
Oosterberg, W., Buijse, A. D., Coops, H., Ibelings, B. W., Menting, G. A. M., Navodaru, I., and Török, L.: Ecological gradients in the Danube Delta lakes: present state and man-induced changes, Institute for Inland Water Management and Waste Water Treatment RIZA, Lelystad, The Netherlands, 2000.
Panin, N.: The Danube Delta, Geomorphology and Holocene Evolution: a Synthesis/Le delta du Danube, Géomorphologie et évolution holocène: une synthèse, Geomorphologie, 9, 247–262, https://doi.org/10.3406/morfo.2003.1188, 2003
Panneer Selvam, B., Natchimuthu, S., Arunachalam, L., and Bastviken, D.: Methane and carbon dioxide emissions from inland waters in India – implications for large scale greenhouse gas balances, Global Change Biol., 20, 3397–3407, https://doi.org/10.1111/gcb.12575, 2014.
Pavel, A., Durisch-Kaiser, E., Balan, S., Radan, S., Sobek, S., and Wehrli, B.: Sources and emission of greenhouse gases in Danube Delta lakes,
Environ. Sci. Pollut. R., 16, 86–91, https://doi.org/10.1007/s11356-009-0182-9, 2009.
Peeters, F., Fernandez, J. E., and Hofmann, H.: Sediment fluxes rather than oxic methanogenesis explain diffusive CH4 emissions from lakes and reservoirs, Sci. Rep.-UK, 9, 243, https://doi.org/10.1038/s41598-018-36530-w, 2019.
Raymond, P. A., Hartmann, J., Lauerwald, R., Sobek, S., McDonald, C., Hoover, M., Butman, D., Striegl, R., Mayorga, E., Humborg, C., and Kortelainen, P.: Global carbon dioxide emissions from inland waters, Nature, 503, 355–359, https://doi.org/10.1038/nature12760, 2013.
Richey, J. E., Melack, J. M., Aufdenkampe, A. K., Ballester, V. M., and Hess, L. L.: Outgassing from Amazonian rivers and wetlands as a large tropical source of atmospheric CO2, Nature, 416, 617–620, https://doi.org/10.1038/416617a, 2002.
Rîşnoveanu, G., Postolache, C., and Vădineanu, A.: Ecological significance of nitrogen cycling by tubificid communities in shallow eutrophic lakes of the Danube Delta, Hydrobiologia, 524, 193–202, https://doi.org/10.1023/B:HYDR.0000036133.92034.69, 2004.
Sanches, L. F., Guenet, B., Marinho, C. C., Barros, N., and de Assis Esteves, F.: Global regulation of methane emission from natural lakes, Sci. Rep.-UK, 9, 255, https://doi.org/10.1038/s41598-018-36519-5, 2019.
Schilder, J., Bastviken, D., van Hardenbroek, M., Kankaala, P., Rinta, P., Stötter, T., and Heiri, O.: Spatial heterogeneity and lake morphology affect diffusive greenhouse gas emission estimates of lakes, Geophys. Res. Lett., 40, 5752–5756, https://doi.org/10.1002/2013GL057669, 2013.
Schubert, C. J. and Wehrli, B.: Contribution of Methane Formation and Methane Oxidation to Methane Emission from Freshwater Systems, in: Biogenesis of Hydrocarbons, edited by: Stams, A. J. M. and Sousa, D., Handbook of Hydrocarbon and Lipid Microbiology, Springer, Cham. 1–31, https://doi.org/10.1007/978-3-319-53114-4_18-1, 2019.
Segers, R.: Methane production and methane consumption: A review of processes underlying wetland methane fluxes, Biogeochemistry, 41, 23–51, https://doi.org/10.1023/A:1005929032764, 1998.
Sepulveda-Jauregui, A., Hoyos-Santillan, J., Martinez-Cruz, K., Walter Anthony, K. M., Casper, P., Belmonte-Izquierdo, Y., and Thalasso, F.: Eutrophication exacerbates the impact of climate warming on lake methane emission, Sci. Total Environ., 636, 411–419, https://doi.org/10.1016/j.scitotenv.2018.04.283, 2018.
Sieczko, A. K., Duc, N. T., Schenk, J., Pajala, G., Rudberg, D., Sawakuchi, H. O., and Bastviken, D.: Diel variability of methane emissions from lakes, P. Natl. Acad. Sci. USA, 117, 21488–21494, https://doi.org/10.1073/pnas.2006024117, 2020.
Spiridon, C., Teodorof, L., Burada, A., Despina, C., Seceleanu-Odor, D., Tudor, I. M., Ibram, O., and Georgescu, L. P.: Seasonal variations of nutrients concentration in aquatic ecosystems from Danube delta biosphere reserve, AACL Bioflux, 11, 1882–1891, 2018.
Stanley, E. H., Casson, N. J., Christel, S. T., Crawford, J. T., Loken, L. C., and Oliver, S. K.: The ecology of methane in streams and rivers: Patterns, controls, and global significance, Ecol. Monogr., 86, 146–171, https://doi.org/10.1890/15-1027, 2016.
Tang, K. W., McGinnis, D. F., Ionescu, D., and Grossart, H. P.: Methane production in oxic lake waters potentially increases aquatic methane flux to air, Environ. Sci. Tech. Let., 3, 227–233, https://doi.org/10.1021/acs.estlett.6b00150, 2016.
Tranvik, L. J., Downing, J. A., Cotner, J. B., Loiselle, S. A., Striegl, R. G., Ballatore, T. J., Dillon, P., Finlay, K., Fortino, K., Knoll, L. B., and Kortelainen, P. L.: Lakes and impoundments as regulators of carbon cycling and climate, Limnol. Oceanogr., 54, 2298–2314, 2009.
Tudor, I.-M., Teodorof, L., Burada, A., Tudor, M., Ibram, O., and Despina, C.: Long-term nutrients and heavy metals concentration dynamics in aquatic ecosystems of Danube Delta. Scientific Annals of the Danube Delta Institute, Tulcea, Romania, 22, 149–156, 2016.
van Bergen, T. J. H. M., Barros, N., Mendonça, R., Aben, R. C., Althuizen, I. H., Huszar, V., Lamers, L. P., Lürling, M., Roland, F., and Kosten, S.: Seasonal and diel variation in greenhouse gas emissions from an urban pond and its major drivers, Limnol. Oceanogr., 64, 2129–2139, https://doi.org/10.1002/lno.11173, 2019.
Wang, D., Chen, Z., Sun, W., Hu, B., and Xu, S.: Methane and nitrous oxide concentration and emission flux of Yangtze Delta plain river net,
Sci. China Ser. B, 52, 652–661, https://doi.org/10.1007/s11426-009-0024-0, 2009.
Wanninkhof, R. H.: Relationship between wind speed and gas exchange, J. Geophys. Res., 97, 7373–7382, 1992.
Ward, N. D., Bianchi, T. S., Medeiros, P. M., Seidel, M., Richey, J. E., Keil, R. G., and Sawakuchi, H. O.: Where Carbon Goes When Water Flows: Carbon Cycling across the Aquatic Continuum, Front. Mar. Sci., 4, 7, https://doi.org/10.3389/fmars.2017.00007, 2017.
Wiesenburg, D. A. and Guinasso Jr., N. L.: Equilibrium solubilities of methane, carbon monoxide, and hydrogen in water and sea water,
J. Chem. Eng. Data, 24, 356–360, 1979.
Woolway, R. I. and Merchant, C. J.: Worldwide alteration of lake mixing regimes in response to climate change, Nat. Geosci., 12, 271–276, https://doi.org/10.1038/s41561-019-0322-x, 2019.
Yvon-Durocher, G., Allen, A. P., Bastviken, D., Conrad, R., Gudasz, C., St-Pierre, A., Thanh-Duc, N., and Del Giorgio, P. A.: Methane fluxes show consistent temperature dependence across microbial to ecosystem scales, Nature, 507, 488–491, https://doi.org/10.1038/nature13164, 2014.
Zhang, C., Cheng, S., Long, L., Xie, H., Mu, X., and Zhang, W.: Diel and seasonal methane flux across water-air interface of a subtropic eutrophic pond, Toxicol. Environ. Chem., 100, 413–424, https://doi.org/10.1080/02772248.2018.1499231, 2018.
Zuidgeest, A., Baumgartner, S., and Wehrli, B.: Hysteresis effects in organic matter turnover in a tropical floodplain during a flood cycle, Biogeochemistry, 131, 49–63, https://doi.org/10.1007/s10533-016-0263-z, 2016.
Short summary
Inland waters are usually not well restrained in terms of greenhouse gas measurements. One of these regions is the Danube Delta, Romania. Therefore, we measured continuously with sensors to collect high-resolution data for CH4 and O2 throughout the Delta. We found significant variation for all concentrations over the day and night and between regions, as well as large spatial variation throughout all regions, with large CH4 concentrations flowing in from the reed beds to the lakes.
Inland waters are usually not well restrained in terms of greenhouse gas measurements. One of...
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