Articles | Volume 20, issue 15
https://doi.org/10.5194/bg-20-3229-2023
© Author(s) 2023. 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-20-3229-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
07 Aug 2023
Research article |
| 07 Aug 2023
| 07 Aug 2023
Seasonal variability of nitrous oxide concentrations and emissions in a temperate estuary
Institute of Geology, Center for Earth System Research and Sustainability (CEN), University of Hamburg, Hamburg, 20146, Germany
Institute of Carbon Cycles, Helmholtz-Zentrum Hereon, Geesthacht, 21502, Germany
Tina Sanders
Institute of Carbon Cycles, Helmholtz-Zentrum Hereon, Geesthacht, 21502, Germany
Yoana G. Voynova
Institute of Carbon Cycles, Helmholtz-Zentrum Hereon, Geesthacht, 21502, Germany
Hermann W. Bange
Marine Biogeochemistry Research Division, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, 24105, Germany
Kirstin Dähnke
Institute of Carbon Cycles, Helmholtz-Zentrum Hereon, Geesthacht, 21502, Germany
Related authors
Riel Carlo O. Ingeniero, Gesa Schulz, and Hermann W. Bange
EGUsphere, https://doi.org/10.5194/egusphere-2023-3009, https://doi.org/10.5194/egusphere-2023-3009, 2023
Short summary
Short summary
Our research is the first to measure dissolved NO concentrations in temperate estuarine waters, providing insights into its distribution under varying conditions and enhancing our understanding of its production processes. We found that the lower Elbe Estuary and the Hamburg Port area were a source of atmospheric NO. Our results suggest that NO in the lower Elbe Estuary was produced during nitrification, whereas NO in the Hamburg Port area was produced during nitrifier-denitrification.
Mona Norbisrath, Johannes Pätsch, Kirstin Dähnke, Tina Sanders, Gesa Schulz, Justus E. E. van Beusekom, and Helmuth Thomas
Biogeosciences, 19, 5151–5165, https://doi.org/10.5194/bg-19-5151-2022, https://doi.org/10.5194/bg-19-5151-2022, 2022
Short summary
Short summary
Total alkalinity (TA) regulates the oceanic storage capacity of atmospheric CO2. TA is also metabolically generated in estuaries and influences coastal carbon storage through its inflows. We used water samples and identified the Hamburg port area as the one with highest TA generation. Of the overall riverine TA load, 14 % is generated within the estuary. Using a biogeochemical model, we estimated potential effects on the coastal carbon storage under possible anthropogenic and climate changes.
Gesa Schulz, Tina Sanders, Justus E. E. van Beusekom, Yoana G. Voynova, Andreas Schöl, and Kirstin Dähnke
Biogeosciences, 19, 2007–2024, https://doi.org/10.5194/bg-19-2007-2022, https://doi.org/10.5194/bg-19-2007-2022, 2022
Short summary
Short summary
Estuaries can significantly alter nutrient loads before reaching coastal waters. Our study of the heavily managed Ems estuary (Northern Germany) reveals three zones of nitrogen turnover along the estuary with water-column denitrification in the most upstream hyper-turbid part, nitrate production in the middle reaches and mixing/nitrate uptake in the North Sea. Suspended particulate matter was the overarching control on nitrogen cycling in the hyper-turbid estuary.
Johnathan D. Maxey, Neil D. Hartstein, Hermann W. Bange, and Mortiz Müller
EGUsphere, https://doi.org/10.5194/egusphere-2024-1731, https://doi.org/10.5194/egusphere-2024-1731, 2024
Short summary
Short summary
The distribution of N2O in fjord-like estuaries is poorly described in the southern hemisphere. Our study describes N2O distribution and its drivers in one such system Macquarie Harbour, Tasmania. Water samples were collected seasonally from 2022/2023. Results show the system is a sink for atmospheric N2O when river flow is high; and the system emits N2O when the river flow is low. N2O generated in basins is intercepted by the surface water and exported to the ocean during high river flow.
Hanqin Tian, Naiqing Pan, Rona L. Thompson, Josep G. Canadell, Parvadha Suntharalingam, Pierre Regnier, Eric A. Davidson, Michael Prather, Philippe Ciais, Marilena Muntean, Shufen Pan, Wilfried Winiwarter, Sönke Zaehle, Feng Zhou, Robert B. Jackson, Hermann W. Bange, Sarah Berthet, Zihao Bian, Daniele Bianchi, Alexander F. Bouwman, Erik T. Buitenhuis, Geoffrey Dutton, Minpeng Hu, Akihiko Ito, Atul K. Jain, Aurich Jeltsch-Thömmes, Fortunat Joos, Sian Kou-Giesbrecht, Paul B. Krummel, Xin Lan, Angela Landolfi, Ronny Lauerwald, Ya Li, Chaoqun Lu, Taylor Maavara, Manfredi Manizza, Dylan B. Millet, Jens Mühle, Prabir K. Patra, Glen P. Peters, Xiaoyu Qin, Peter Raymond, Laure Resplandy, Judith A. Rosentreter, Hao Shi, Qing Sun, Daniele Tonina, Francesco N. Tubiello, Guido R. van der Werf, Nicolas Vuichard, Junjie Wang, Kelley C. Wells, Luke M. Western, Chris Wilson, Jia Yang, Yuanzhi Yao, Yongfa You, and Qing Zhu
Earth Syst. Sci. Data, 16, 2543–2604, https://doi.org/10.5194/essd-16-2543-2024, https://doi.org/10.5194/essd-16-2543-2024, 2024
Short summary
Short summary
Atmospheric concentrations of nitrous oxide (N2O), a greenhouse gas 273 times more potent than carbon dioxide, have increased by 25 % since the preindustrial period, with the highest observed growth rate in 2020 and 2021. This rapid growth rate has primarily been due to a 40 % increase in anthropogenic emissions since 1980. Observed atmospheric N2O concentrations in recent years have exceeded the worst-case climate scenario, underscoring the importance of reducing anthropogenic N2O emissions.
Riel Carlo O. Ingeniero, Gesa Schulz, and Hermann W. Bange
EGUsphere, https://doi.org/10.5194/egusphere-2023-3009, https://doi.org/10.5194/egusphere-2023-3009, 2023
Short summary
Short summary
Our research is the first to measure dissolved NO concentrations in temperate estuarine waters, providing insights into its distribution under varying conditions and enhancing our understanding of its production processes. We found that the lower Elbe Estuary and the Hamburg Port area were a source of atmospheric NO. Our results suggest that NO in the lower Elbe Estuary was produced during nitrification, whereas NO in the Hamburg Port area was produced during nitrifier-denitrification.
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
Short summary
Short summary
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.
Mona Norbisrath, Andreas Neumann, Kirstin Dähnke, Tina Sanders, Andreas Schöl, Justus E. E. van Beusekom, and Helmuth Thomas
Biogeosciences, 20, 4307–4321, https://doi.org/10.5194/bg-20-4307-2023, https://doi.org/10.5194/bg-20-4307-2023, 2023
Short summary
Short summary
Total alkalinity (TA) is the oceanic capacity to store CO2. Estuaries can be a TA source. Anaerobic metabolic pathways like denitrification (reduction of NO3− to N2) generate TA and are a major nitrogen (N) sink. Another important N sink is anammox that transforms NH4+ with NO2− into N2 without TA generation. By combining TA and N2 production, we identified a TA source, denitrification, occurring in the water column and suggest anammox as the dominant N2 producer in the bottom layer of the Ems.
Guanlin Li, Damian L. Arévalo-Martínez, Riel Carlo O. Ingeniero, and Hermann W. Bange
EGUsphere, https://doi.org/10.5194/egusphere-2023-771, https://doi.org/10.5194/egusphere-2023-771, 2023
Preprint archived
Short summary
Short summary
Dissolved carbon monoxide (CO) surface concentrations were first measured at 14 stations in the Ria Formosa Lagoon system in May 2021. Ria Formosa was a source of atmospheric CO. Microbial consumption accounted for 83 % of the CO production. The results of a 48-hour irradiation experiment with aquaculture effluent water indicated that aquaculture facilities in the Ria Formosa Lagoon seem to be a negligible source of atmospheric CO.
Olga Ogneva, Gesine Mollenhauer, Bennet Juhls, Tina Sanders, Juri Palmtag, Matthias Fuchs, Hendrik Grotheer, Paul J. Mann, and Jens Strauss
Biogeosciences, 20, 1423–1441, https://doi.org/10.5194/bg-20-1423-2023, https://doi.org/10.5194/bg-20-1423-2023, 2023
Short summary
Short summary
Arctic warming accelerates permafrost thaw and release of terrestrial organic matter (OM) via rivers to the Arctic Ocean. We compared particulate organic carbon (POC), total suspended matter, and C isotopes (δ13C and Δ14C of POC) in the Lena delta and Lena River along a ~1600 km transect. We show that the Lena delta, as an interface between the Lena River and the Arctic Ocean, plays a crucial role in determining the qualitative and quantitative composition of OM discharged into the Arctic Ocean.
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
Short summary
Short summary
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.
Damian L. Arévalo-Martínez, Amir Haroon, Hermann W. Bange, Ercan Erkul, Marion Jegen, Nils Moosdorf, Jens Schneider von Deimling, Christian Berndt, Michael Ernst Böttcher, Jasper Hoffmann, Volker Liebetrau, Ulf Mallast, Gudrun Massmann, Aaron Micallef, Holly A. Michael, Hendrik Paasche, Wolfgang Rabbel, Isaac Santos, Jan Scholten, Katrin Schwalenberg, Beata Szymczycha, Ariel T. Thomas, Joonas J. Virtasalo, Hannelore Waska, and Bradley A. Weymer
Biogeosciences, 20, 647–662, https://doi.org/10.5194/bg-20-647-2023, https://doi.org/10.5194/bg-20-647-2023, 2023
Short summary
Short summary
Groundwater flows at the land–ocean transition and the extent of freshened groundwater below the seafloor are increasingly relevant in marine sciences, both because they are a highly uncertain term of biogeochemical budgets and due to the emerging interest in the latter as a resource. Here, we discuss our perspectives on future research directions to better understand land–ocean connectivity through groundwater and its potential responses to natural and human-induced environmental changes.
Kirstin Dähnke, Tina Sanders, Yoana Voynova, and Scott D. Wankel
Biogeosciences, 19, 5879–5891, https://doi.org/10.5194/bg-19-5879-2022, https://doi.org/10.5194/bg-19-5879-2022, 2022
Short summary
Short summary
Nitrogen is an important macronutrient that fuels algal production in rivers and coastal regions. We investigated the production and removal of nitrogen-bearing compounds in the freshwater section of the tidal Elbe Estuary and found that particles in the water column are key for the production and removal of water column nitrate. Using a stable isotope approach, we pinpointed regions where additional removal of nitrate or input from sediments plays an important role in estuarine biogeochemistry.
Mona Norbisrath, Johannes Pätsch, Kirstin Dähnke, Tina Sanders, Gesa Schulz, Justus E. E. van Beusekom, and Helmuth Thomas
Biogeosciences, 19, 5151–5165, https://doi.org/10.5194/bg-19-5151-2022, https://doi.org/10.5194/bg-19-5151-2022, 2022
Short summary
Short summary
Total alkalinity (TA) regulates the oceanic storage capacity of atmospheric CO2. TA is also metabolically generated in estuaries and influences coastal carbon storage through its inflows. We used water samples and identified the Hamburg port area as the one with highest TA generation. Of the overall riverine TA load, 14 % is generated within the estuary. Using a biogeochemical model, we estimated potential effects on the coastal carbon storage under possible anthropogenic and climate changes.
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
Short summary
Short summary
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.
Matthias Fuchs, Juri Palmtag, Bennet Juhls, Pier Paul Overduin, Guido Grosse, Ahmed Abdelwahab, Michael Bedington, Tina Sanders, Olga Ogneva, Irina V. Fedorova, Nikita S. Zimov, Paul J. Mann, and Jens Strauss
Earth Syst. Sci. Data, 14, 2279–2301, https://doi.org/10.5194/essd-14-2279-2022, https://doi.org/10.5194/essd-14-2279-2022, 2022
Short summary
Short summary
We created digital, high-resolution bathymetry data sets for the Lena Delta and Kolyma Gulf regions in northeastern Siberia. Based on nautical charts, we digitized depth points and isobath lines, which serve as an input for a 50 m bathymetry model. The benefit of this data set is the accurate mapping of near-shore areas as well as the offshore continuation of the main deep river channels. This will improve the estimation of river outflow and the nutrient flux output into the coastal zone.
Shichao Tian, Birgit Gaye, Jianhui Tang, Yongming Luo, Wenguo Li, Niko Lahajnar, Kirstin Dähnke, Tina Sanders, Tianqi Xiong, Weidong Zhai, and Kay-Christian Emeis
Biogeosciences, 19, 2397–2415, https://doi.org/10.5194/bg-19-2397-2022, https://doi.org/10.5194/bg-19-2397-2022, 2022
Short summary
Short summary
We constrain the nitrogen budget and in particular the internal sources and sinks of nitrate in the Bohai Sea by using a mass-based and dual stable isotope approach based on δ15N and δ18O of nitrate. Based on available mass fluxes and isotope data an updated nitrogen budget is proposed. Compared to previous estimates, it is more complete and includes the impact of the interior cycle (nitrification) on the nitrate pool. The main external nitrogen sources are rivers contributing 19.2 %–25.6 %.
Charlotte Haugk, Loeka L. Jongejans, Kai Mangelsdorf, Matthias Fuchs, Olga Ogneva, Juri Palmtag, Gesine Mollenhauer, Paul J. Mann, P. Paul Overduin, Guido Grosse, Tina Sanders, Robyn E. Tuerena, Lutz Schirrmeister, Sebastian Wetterich, Alexander Kizyakov, Cornelia Karger, and Jens Strauss
Biogeosciences, 19, 2079–2094, https://doi.org/10.5194/bg-19-2079-2022, https://doi.org/10.5194/bg-19-2079-2022, 2022
Short summary
Short summary
Buried animal and plant remains (carbon) from the last ice age were freeze-locked in permafrost. At an extremely fast eroding permafrost cliff in the Lena Delta (Siberia), we found this formerly frozen carbon well preserved. Our results show that ongoing degradation releases substantial amounts of this carbon, making it available for future carbon emissions. This mobilisation at the studied cliff and also similarly eroding sites bear the potential to affect rivers and oceans negatively.
Gesa Schulz, Tina Sanders, Justus E. E. van Beusekom, Yoana G. Voynova, Andreas Schöl, and Kirstin Dähnke
Biogeosciences, 19, 2007–2024, https://doi.org/10.5194/bg-19-2007-2022, https://doi.org/10.5194/bg-19-2007-2022, 2022
Short summary
Short summary
Estuaries can significantly alter nutrient loads before reaching coastal waters. Our study of the heavily managed Ems estuary (Northern Germany) reveals three zones of nitrogen turnover along the estuary with water-column denitrification in the most upstream hyper-turbid part, nitrate production in the middle reaches and mixing/nitrate uptake in the North Sea. Suspended particulate matter was the overarching control on nitrogen cycling in the hyper-turbid estuary.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Onur Kerimoglu, Yoana G. Voynova, Fatemeh Chegini, Holger Brix, Ulrich Callies, Richard Hofmeister, Knut Klingbeil, Corinna Schrum, and Justus E. E. van Beusekom
Biogeosciences, 17, 5097–5127, https://doi.org/10.5194/bg-17-5097-2020, https://doi.org/10.5194/bg-17-5097-2020, 2020
Short summary
Short summary
In this study, using extensive field observations and a numerical model, we analyzed the physical and biogeochemical structure of a coastal system following an extreme flood event. Our results suggest that a number of anomalous observations were driven by a co-occurrence of peculiar meteorological conditions and increased riverine discharges. Our results call for attention to the combined effects of hydrological and meteorological extremes that are anticipated to increase in frequency.
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
Short summary
Short summary
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.
Alexander Bratek, Justus E. E. van
Beusekom, Andreas Neumann, Tina Sanders, Jana Friedrich, Kay-Christian Emeis, and Kirstin Dähnke
Biogeosciences, 17, 2839–2851, https://doi.org/10.5194/bg-17-2839-2020, https://doi.org/10.5194/bg-17-2839-2020, 2020
Short summary
Short summary
The following paper highlights the importance of benthic N-transformation rates in different sediment types in the southern North Sea as a source of fixed nitrogen for primary producers and also as a sink of fixed nitrogen. Sedimentary fluxes of dissolved inorganic nitrogen support ∼7 to 59 % of the average annual primary production. Semi-permeable and permeable sediments contribute ∼68 % of the total benthic N2 production rates, counteracting eutrophication in the southern North Sea.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Natalie C. Harms, Niko Lahajnar, Birgit Gaye, Tim Rixen, Kirstin Dähnke, Markus Ankele, Ulrich Schwarz-Schampera, and Kay-Christian Emeis
Biogeosciences, 16, 2715–2732, https://doi.org/10.5194/bg-16-2715-2019, https://doi.org/10.5194/bg-16-2715-2019, 2019
Short summary
Short summary
The Indian Ocean subtropical gyre is a large oligotrophic area that is likely to adjust to continued warming by increasing stratification, reduced nutrient supply and decreasing biological production. In this study, we investigated concentrations of nutrients and stable isotopes of nitrate. We determine the lateral influence of water masses entering the gyre from the northern Indian Ocean and from the Southern Ocean and quantify the input of nitrogen by N2 fixation into the surface layer.
Johannes Pein, Annika Eisele, Richard Hofmeister, Tina Sanders, Ute Daewel, Emil V. Stanev, Justus van Beusekom, Joanna Staneva, and Corinna Schrum
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-265, https://doi.org/10.5194/bg-2019-265, 2019
Revised manuscript not accepted
Short summary
Short summary
The Elbe estuary is subject to vigorous tidal forcing from the sea side and considerable biological inputs from the land side. Our 3D numerical coupled physical-biogeochemical integrates these forcing signals and provides highly realistic hindcasts of the associated dynamics. Model simulations show that the freshwater part of Elbe estuary is inhabited by plankton. According to simulations these organism play a key role in converting organic inputs into nitrate, the major inorganic nutrient.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Samuel T. Wilson, Hermann W. Bange, Damian L. Arévalo-Martínez, Jonathan Barnes, Alberto V. Borges, Ian Brown, John L. Bullister, Macarena Burgos, David W. Capelle, Michael Casso, Mercedes de la Paz, Laura Farías, Lindsay Fenwick, Sara Ferrón, Gerardo Garcia, Michael Glockzin, David M. Karl, Annette Kock, Sarah Laperriere, Cliff S. Law, Cara C. Manning, Andrew Marriner, Jukka-Pekka Myllykangas, John W. Pohlman, Andrew P. Rees, Alyson E. Santoro, Philippe D. Tortell, Robert C. Upstill-Goddard, David P. Wisegarver, Gui-Ling Zhang, and Gregor Rehder
Biogeosciences, 15, 5891–5907, https://doi.org/10.5194/bg-15-5891-2018, https://doi.org/10.5194/bg-15-5891-2018, 2018
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Yoana G. Voynova, Holger Brix, Wilhelm Petersen, Sieglinde Weigelt-Krenz, and Mirco Scharfe
Biogeosciences, 14, 541–557, https://doi.org/10.5194/bg-14-541-2017, https://doi.org/10.5194/bg-14-541-2017, 2017
Short summary
Short summary
This study focuses on how the June 2013 Elbe River flood affected the southern German Bight. The largest summer flood within the last 140 years, it generated a substantial plume of nutrient-rich, buoyant waters from the Elbe estuary onto the coast. During the calm 2013 summer, the flood was followed by prolonged (2-month) water column stratification, chlorophyll blooms in surface, and uncharacteristically low oxygen in bottom waters. With climate change, these events are becoming more frequent.
Juliane Jacob, Tina Sanders, and Kirstin Dähnke
Biogeosciences, 13, 5649–5659, https://doi.org/10.5194/bg-13-5649-2016, https://doi.org/10.5194/bg-13-5649-2016, 2016
Short summary
Short summary
During a flood in the Elbe in June 2013, a unique co-occurrence of ammonium, nitrite and nitrate in the water column was found. SPM and nutrient concentrations as well as isotopes were analysed. We calculated an isotope effect 15ε of −10.0 ± 0.1 ‰ during net nitrite and 15ε of −4.0 ± 0.1 ‰ and 18ε of −5.3 ± 0.1 ‰ during net nitrate consumption. A simple box-model calculation results in combined riparian denitrification and 22 to 36 % nitrification.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
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
B. Gaye, B. Nagel, K. Dähnke, T. Rixen, N. Lahajnar, and K.-C. Emeis
Biogeosciences, 10, 7689–7702, https://doi.org/10.5194/bg-10-7689-2013, https://doi.org/10.5194/bg-10-7689-2013, 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
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
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
K. Dähnke and B. Thamdrup
Biogeosciences, 10, 3079–3088, https://doi.org/10.5194/bg-10-3079-2013, https://doi.org/10.5194/bg-10-3079-2013, 2013
L. M. Zamora, A. Oschlies, H. W. Bange, K. B. Huebert, J. D. Craig, A. Kock, and C. R. Löscher
Biogeosciences, 9, 5007–5022, https://doi.org/10.5194/bg-9-5007-2012, https://doi.org/10.5194/bg-9-5007-2012, 2012
Related subject area
Biogeochemistry: Greenhouse Gases
Modelling CO2 and N2O emissions from soils in silvopastoral systems of the West African Sahelian band
A case study on topsoil removal and rewetting for paludiculture: effect on biogeochemistry and greenhouse gas emissions from Typha latifolia, Typha angustifolia, and Azolla filiculoides
Assessing improvements in global ocean pCO2 machine learning reconstructions with Southern Ocean autonomous sampling
Timescale dependence of airborne fraction and underlying climate–carbon-cycle feedbacks for weak perturbations in CMIP5 models
Technical note: Preventing CO2 overestimation from mercuric or copper(II) chloride preservation of dissolved greenhouse gases in freshwater samples
Exploring temporal and spatial variation of nitrous oxide flux using several years of peatland forest automatic chamber data
Diurnal versus spatial variability of greenhouse gas emissions from an anthropogenically modified lowland river in Germany
Regional assessment and uncertainty analysis of carbon and nitrogen balances at cropland scale using the ecosystem model LandscapeDNDC
Resolving heterogeneous fluxes from tundra halves the growing season carbon budget
Lawns and meadows in urban green space – a comparison from perspectives of greenhouse gases, drought resilience and plant functional types
Large contribution of soil N2O emission to the global warming potential of a large-scale oil palm plantation despite changing from conventional to reduced management practices
Influence of wind strength and direction on diffusive methane fluxes and atmospheric methane concentrations above the North Sea
Identifying landscape hot and cold spots of soil greenhouse gas fluxes by combining field measurements and remote sensing data
The emission of CO from tropical rain forest soils
Using Eddy Covariance Observations to Determine the Carbon Sequestration Characteristics of Subalpine Forests in the Qinghai-Tibet Plateau
Isotopomer labeling and oxygen dependence of hybrid nitrous oxide production
Enhanced Southern Ocean CO2 outgassing as a result of stronger and poleward shifted southern hemispheric westerlies
Spatial and temporal variability of methane emissions and environmental conditions in a hyper-eutrophic fishpond
Optical and radar Earth observation data for upscaling methane emissions linked to permafrost degradation in sub-Arctic peatlands in northern Sweden
Herbivore–shrub interactions influence ecosystem respiration and biogenic volatile organic compound composition in the subarctic
Methane emissions due to reservoir flushing: a significant emission pathway?
Carbon dioxide and methane fluxes from mounds of African fungus-growing termites
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
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
Meteorological responses of carbon dioxide and methane fluxes in the terrestrial and aquatic ecosystems of a subarctic landscape
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
Yélognissè Agbohessou, Claire Delon, Manuela Grippa, Eric Mougin, Daouda Ngom, Espoir Koudjo Gaglo, Ousmane Ndiaye, Paulo Salgado, and Olivier Roupsard
Biogeosciences, 21, 2811–2837, https://doi.org/10.5194/bg-21-2811-2024, https://doi.org/10.5194/bg-21-2811-2024, 2024
Short summary
Short summary
Emissions of greenhouse gases in the Sahel are not well represented because they are considered weak compared to the rest of the world. However, natural areas in the Sahel emit carbon dioxide and nitrous oxides, which need to be assessed because of extended surfaces. We propose an assessment of such emissions in Sahelian silvopastoral systems and of how they are influenced by environmental characteristics. These results are essential to inform climate change strategies in the region.
Merit van den Berg, Thomas M. Gremmen, Renske J. E. Vroom, Jacobus van Huissteden, Jim Boonman, Corine J. A. van Huissteden, Ype van der Velde, Alfons J. P. Smolders, and Bas P. van de Riet
Biogeosciences, 21, 2669–2690, https://doi.org/10.5194/bg-21-2669-2024, https://doi.org/10.5194/bg-21-2669-2024, 2024
Short summary
Short summary
Drained peatlands emit 3 % of the global greenhouse gas emissions. Paludiculture is a way to reduce CO2 emissions while at the same time generating an income for landowners. The side effect is the potentially high methane emissions. We found very high methane emissions for broadleaf cattail compared with narrowleaf cattail and water fern. The rewetting was, however, effective to stop CO2 emissions for all species. The highest potential to reduce greenhouse gas emissions had narrowleaf cattail.
Thea H. Heimdal, Galen A. McKinley, Adrienne J. Sutton, Amanda R. Fay, and Lucas Gloege
Biogeosciences, 21, 2159–2176, https://doi.org/10.5194/bg-21-2159-2024, https://doi.org/10.5194/bg-21-2159-2024, 2024
Short summary
Short summary
Measurements of ocean carbon are limited in time and space. Machine learning algorithms are therefore used to reconstruct ocean carbon where observations do not exist. Improving these reconstructions is important in order to accurately estimate how much carbon the ocean absorbs from the atmosphere. In this study, we find that a small addition of observations from the Southern Ocean, obtained by autonomous sampling platforms, could significantly improve the reconstructions.
Guilherme L. Torres Mendonça, Julia Pongratz, and Christian H. Reick
Biogeosciences, 21, 1923–1960, https://doi.org/10.5194/bg-21-1923-2024, https://doi.org/10.5194/bg-21-1923-2024, 2024
Short summary
Short summary
We study the timescale dependence of airborne fraction and underlying feedbacks by a theory of the climate–carbon system. Using simulations we show the predictive power of this theory and find that (1) this fraction generally decreases for increasing timescales and (2) at all timescales the total feedback is negative and the model spread in a single feedback causes the spread in the airborne fraction. Our study indicates that those are properties of the system, independently of the scenario.
François Clayer, Jan Erik Thrane, Kuria Ndungu, Andrew King, Peter Dörsch, and Thomas Rohrlack
Biogeosciences, 21, 1903–1921, https://doi.org/10.5194/bg-21-1903-2024, https://doi.org/10.5194/bg-21-1903-2024, 2024
Short summary
Short summary
Determination of dissolved greenhouse gas (GHG) in freshwater allows us to estimate GHG fluxes. Mercuric chloride (HgCl2) is used to preserve water samples prior to GHG analysis despite its environmental and health impacts and interferences with water chemistry in freshwater. Here, we tested the effects of HgCl2, two substitutes and storage time on GHG in water from two boreal lakes. Preservation with HgCl2 caused overestimation of CO2 concentration with consequences for GHG flux estimation.
Helena Rautakoski, Mika Korkiakoski, Jarmo Mäkelä, Markku Koskinen, Kari Minkkinen, Mika Aurela, Paavo Ojanen, and Annalea Lohila
Biogeosciences, 21, 1867–1886, https://doi.org/10.5194/bg-21-1867-2024, https://doi.org/10.5194/bg-21-1867-2024, 2024
Short summary
Short summary
Current and future nitrous oxide (N2O) emissions are difficult to estimate due to their high variability in space and time. Several years of N2O fluxes from drained boreal peatland forest indicate high importance of summer precipitation, winter temperature, and snow conditions in controlling annual N2O emissions. The results indicate increasing year-to-year variation in N2O emissions in changing climate with more extreme seasonal weather conditions.
Matthias Koschorreck, Norbert Kamjunke, Uta Koedel, Michael Rode, Claudia Schuetze, and Ingeborg Bussmann
Biogeosciences, 21, 1613–1628, https://doi.org/10.5194/bg-21-1613-2024, https://doi.org/10.5194/bg-21-1613-2024, 2024
Short summary
Short summary
We measured the emission of carbon dioxide (CO2) and methane (CH4) from different sites at the river Elbe in Germany over 3 days to find out what is more important for quantification: small-scale spatial variability or diurnal temporal variability. We found that CO2 emissions were very different between day and night, while CH4 emissions were more different between sites. Dried out river sediments contributed to CO2 emissions, while the side areas of the river were important CH4 sources.
Odysseas Sifounakis, Edwin Haas, Klaus Butterbach-Bahl, and Maria P. Papadopoulou
Biogeosciences, 21, 1563–1581, https://doi.org/10.5194/bg-21-1563-2024, https://doi.org/10.5194/bg-21-1563-2024, 2024
Short summary
Short summary
We performed a full assessment of the carbon and nitrogen cycles of a cropland ecosystem. An uncertainty analysis and quantification of all carbon and nitrogen fluxes were deployed. The inventory simulations include greenhouse gas emissions of N2O, NH3 volatilization and NO3 leaching from arable land cultivation in Greece. The inventory also reports changes in soil organic carbon and nitrogen stocks in arable soils.
Sarah M. Ludwig, Luke Schiferl, Jacqueline Hung, Susan M. Natali, and Roisin Commane
Biogeosciences, 21, 1301–1321, https://doi.org/10.5194/bg-21-1301-2024, https://doi.org/10.5194/bg-21-1301-2024, 2024
Short summary
Short summary
Landscapes are often assumed to be homogeneous when using eddy covariance fluxes, which can lead to biases when calculating carbon budgets. In this study we report eddy covariance carbon fluxes from heterogeneous tundra. We used the footprints of each flux observation to unmix the fluxes coming from components of the landscape. We identified and quantified hot spots of carbon emissions in the landscape. Accurately scaling with landscape heterogeneity yielded half as much regional carbon uptake.
Justine Trémeau, Beñat Olascoaga, Leif Backman, Esko Karvinen, Henriikka Vekuri, and Liisa Kulmala
Biogeosciences, 21, 949–972, https://doi.org/10.5194/bg-21-949-2024, https://doi.org/10.5194/bg-21-949-2024, 2024
Short summary
Short summary
We studied urban lawns and meadows in the Helsinki metropolitan area, Finland. We found that meadows are more resistant to drought events but that they do not increase carbon sequestration compared with lawns. Moreover, the transformation from lawns to meadows did not demonstrate any negative climate effects in terms of greenhouse gas emissions. Even though social and economic aspects also steer urban development, these results can guide planning to consider carbon-smart options.
Guantao Chen, Edzo Veldkamp, Muhammad Damris, Bambang Irawan, Aiyen Tjoa, and Marife D. Corre
Biogeosciences, 21, 513–529, https://doi.org/10.5194/bg-21-513-2024, https://doi.org/10.5194/bg-21-513-2024, 2024
Short summary
Short summary
We established an oil palm management experiment in a large-scale oil palm plantation in Jambi, Indonesia. We recorded oil palm fruit yield and measured soil CO2, N2O, and CH4 fluxes. After 4 years of treatment, compared with conventional fertilization with herbicide weeding, reduced fertilization with mechanical weeding did not reduce yield and soil greenhouse gas emissions, which highlights the legacy effects of over a decade of conventional management prior to the start of the experiment.
Ingeborg Bussmann, Eric P. Achterberg, Holger Brix, Nicolas Brüggemann, Götz Flöser, Claudia Schütze, and Philipp Fischer
EGUsphere, https://doi.org/10.5194/egusphere-2023-3018, https://doi.org/10.5194/egusphere-2023-3018, 2024
Short summary
Short summary
Methane (CH4) is an important greenhouse gas and contributes to climate warming. The input of CH4 from coastal areas to the atmosphere however is not well defined. Dissolved and atmospheric CH4 was determined at high spatial resolution in or above the North Sea. The atmospheric CH4 concentration was mainly influenced by wind direction. With our detailed study on the spatial distribution of CH4 fluxes we were able to provide a detailed and more realistic estimation of coastal CH4 fluxes.
Elizabeth Gachibu Wangari, Ricky Mwangada Mwanake, Tobias Houska, David Kraus, Gretchen Maria Gettel, Ralf Kiese, Lutz Breuer, and Klaus Butterbach-Bahl
Biogeosciences, 20, 5029–5067, https://doi.org/10.5194/bg-20-5029-2023, https://doi.org/10.5194/bg-20-5029-2023, 2023
Short summary
Short summary
Agricultural landscapes act as sinks or sources of the greenhouse gases (GHGs) CO2, CH4, or N2O. Various physicochemical and biological processes control the fluxes of these GHGs between ecosystems and the atmosphere. Therefore, fluxes depend on environmental conditions such as soil moisture, soil temperature, or soil parameters, which result in large spatial and temporal variations of GHG fluxes. Here, we describe an example of how this variation may be studied and analyzed.
Hella van Asperen, Thorsten Warneke, Alessandro Carioca de Araújo, Bruce Forsberg, Sávio José Filgueiras Ferreira, Thomas Röckmann, Carina van der Veen, Sipko Bulthuis, Leonardo Ramos de Oliveira, Thiago de Lima Xavier, Jailson da Mata, Marta de Oliveira Sá, Paulo Ricardo Teixeira, Julie Andrews de França e Silva, Susan Trumbore, and Justus Notholt
EGUsphere, https://doi.org/10.5194/egusphere-2023-2746, https://doi.org/10.5194/egusphere-2023-2746, 2023
Short summary
Short summary
Carbon monoxide (CO) is considered an important indirect greenhouse gas. Soils can emit as well as take up CO but, until now, uncertainty remains which process dominates in tropical rain forests. We present the first soil CO flux measurements from a tropical rain forest. Based on our observations, we report that tropical rain forest soils are a net source of CO. In addition, we show that valley streams and inundated areas are likely additional hot spots of CO in the ecosystem.
Niu Zhu, Jinniu Wang, Dongliang Luo, Xufeng Wang, Cheng Shen, and Ning Wu
EGUsphere, https://doi.org/10.5194/egusphere-2023-2669, https://doi.org/10.5194/egusphere-2023-2669, 2023
Short summary
Short summary
Our study delves into the vital role of subalpine forest in the Qinghai-Tibet Plateau as carbon sinks in the context of climate change. Utilizing advanced eddy covariance systems, we uncover their significant carbon sequestration potential, observing distinct seasonal patterns influenced by temperature, humidity, and radiation. Notably, these forest exhibit robust carbon absorption, with potential implications for global carbon balance.
Colette L. Kelly, Nicole M. Travis, Pascale A. Baya, Claudia Frey, Xin Sun, Bess B. Ward, and Karen L. Casciotti
EGUsphere, https://doi.org/10.5194/egusphere-2023-2642, https://doi.org/10.5194/egusphere-2023-2642, 2023
Short summary
Short summary
We investigated the origins of nitrous oxide, a potent greenhouse gas, in low oxygen ocean regions. Our findings shed light on the microbial processes behind nitrous oxide production, including “hybrid” nitrous oxide generation by ammonia-oxidizing archaea, one of the most abundant organisms in the ocean. We also observed a strong link between nitrous oxide production and oxygen levels. These results set up potential feedbacks between oxygen depletion and greenhouse gas cycling in the oceans.
Laurie C. Menviel, Paul Spence, Andrew E. Kiss, Matthew A. Chamberlain, Hakase Hayashida, Matthew H. England, and Darryn Waugh
Biogeosciences, 20, 4413–4431, https://doi.org/10.5194/bg-20-4413-2023, https://doi.org/10.5194/bg-20-4413-2023, 2023
Short summary
Short summary
As the ocean absorbs 25% of the anthropogenic emissions of carbon, it is important to understand the impact of climate change on the flux of carbon between the ocean and the atmosphere. Here, we use a very high-resolution ocean, sea-ice, carbon cycle model to show that the capability of the Southern Ocean to uptake CO2 has decreased over the last 40 years due to a strengthening and poleward shift of the southern hemispheric westerlies. This trend is expected to continue over the coming century.
Petr Znachor, Jiří Nedoma, Vojtech Kolar, and Anna Matoušů
Biogeosciences, 20, 4273–4288, https://doi.org/10.5194/bg-20-4273-2023, https://doi.org/10.5194/bg-20-4273-2023, 2023
Short summary
Short summary
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. This could be explained only by the water depth. Wind substantially affected temperature, oxygen and chlorophyll a distribution in the pond.
Sofie Sjögersten, Martha Ledger, Matthias Siewert, Betsabé de la Barreda-Bautista, Andrew Sowter, David Gee, Giles Foody, and Doreen S. Boyd
Biogeosciences, 20, 4221–4239, https://doi.org/10.5194/bg-20-4221-2023, https://doi.org/10.5194/bg-20-4221-2023, 2023
Short summary
Short summary
Permafrost thaw in Arctic regions is increasing methane emissions, but quantification is difficult given the large and remote areas impacted. We show that UAV data together with satellite data can be used to extrapolate emissions across the wider landscape as well as detect areas at risk of higher emissions. A transition of currently degrading areas to fen type vegetation can increase emission by several orders of magnitude, highlighting the importance of quantifying areas at risk.
Cole G. Brachmann, Tage Vowles, Riikka Rinnan, Mats P. Björkman, Anna Ekberg, and Robert G. Björk
Biogeosciences, 20, 4069–4086, https://doi.org/10.5194/bg-20-4069-2023, https://doi.org/10.5194/bg-20-4069-2023, 2023
Short summary
Short summary
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.
Ole Lessmann, Jorge Encinas Fernández, Karla Martínez-Cruz, and Frank Peeters
Biogeosciences, 20, 4057–4068, https://doi.org/10.5194/bg-20-4057-2023, https://doi.org/10.5194/bg-20-4057-2023, 2023
Short summary
Short summary
Based on a large dataset of seasonally resolved methane (CH4) pore water concentrations in a reservoir's sediment, we assess the significance of CH4 emissions due to reservoir flushing. In the studied reservoir, CH4 emissions caused by one flushing operation can represent 7 %–14 % of the annual CH4 emissions and depend on the timing of the flushing operation. In reservoirs with high sediment loadings, regular flushing may substantially contribute to the overall CH4 emissions.
Matti Räsänen, Risto Vesala, Petri Rönnholm, Laura Arppe, Petra Manninen, Markus Jylhä, Jouko Rikkinen, Petri Pellikka, and Janne Rinne
Biogeosciences, 20, 4029–4042, https://doi.org/10.5194/bg-20-4029-2023, https://doi.org/10.5194/bg-20-4029-2023, 2023
Short summary
Short summary
Fungus-growing termites recycle large parts 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 in 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 at up to 2 m distance from the mound.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Cited articles
Amann, T., Weiss, A., and Hartmann, J.:
Carbon dynamics in the freshwater part of the Elbe estuary, Germany: Implications of improving water quality, Estuar. Coast. Shelf S., 107, 112–121, https://doi.org/10.1016/j.ecss.2012.05.012, 2012.
Bange, H. W.:
Nitrous oxide and methane in European coastal waters, Estuar. Coast. Shelf S., 70, 361–374, https://doi.org/10.1016/j.ecss.2006.05.042, 2006.
Bange, H. W.:
Gaseous Nitrogen Compounds (NO, N2O, N2, NH3) in the Ocean, Chap. 2, in: Nitrogen in the Marine Environment, 2nd Edn., edited by: Capone, D. G., Bronk, D. A., Mulholland, M. R., and Carpenter, E. J., https://doi.org/10.1016/B978-0-12-372522-6.00002-5, 51–94, ISBN 9780123725226, 2008.
Barnes, J. and Owens, N. J. P.:
Denitrification and Nitrous Oxide Concentrations in the Humber Estuary, UK, and Adjacent Coastal Zones, Mar. Pollut. Bull., 37, 247–260, https://doi.org/10.1016/S0025-326X(99)00079-X, 1999.
Barnes, J. and Upstill-Goddard, R. C.:
N2O seasonal distributions and air–sea exchange in UK estuaries: Implications for the tropospheric N2O source from European coastal waters, J. Geophys. Res.-Biogeo., 116, G01006, https://doi.org/10.1029/2009JG001156, 2011.
Barnes, J., Ramesh, R., Purvaja, R., Nirmal Rajkumar, A., Senthil Kumar, B., Krithika, K., Ravichandran, K., Uher, G., and Upstill-Goddard, R.:
Tidal dynamics and rainfall control N2O and CH4 emissions from a pristine mangrove creek, Geophys. Res. Lett., 33, L15405, https://doi.org/10.1029/2006GL026829, 2006.
Baulch, H. M., Dillon, P. J., Maranger, R., Venkiteswaran, J. J., Wilson, H. F., and Schiff, S. L.:
Night and day: short-term variation in nitrogen chemistry and nitrous oxide emissions from streams, Freshwater Biol., 57, 509–525, https://doi.org/10.1111/j.1365-2427.2011.02720.x, 2012.
Beaulieu, J. J., Shuster, W. D., and Rebholz, J. A.:
Nitrous Oxide Emissions from a Large, Impounded River: The Ohio River, Environ. Sci. Technol., 44, 7527–7533, https://doi.org/10.1021/es1016735, 2010.
Bergemann, M.:
Die Trübungszone in der Tideelbe – Beschreibung der räumlichen und zeitlichen Entwicklung, Wassergütestelle Elbe, https://www.fgg-elbe.de/files/Download-Archive/Fachberichte/Truebungsverhaeltnisse/04Truebungsz.pdf (last access: 27 July 2023), 2004.
Bergemann, M. and Gaumert, T.:
Elbebericht 2008: Ergebnisse des nationalen Überwachungsprogramms Elbe der Bundesländerüber den ökologischen und chemischen Zustand der Elbe nach EG-WRRLsowie der Trendentwicklung von Stoffen und Schadstoffgruppen, Flussgebietsgemeinschaft Elbe (FGG Elbe), Hamburg, https://www.fgg-elbe.de/berichte/aktualisierung-nach-art-13-2021.html?file=files/Downloads/EG_WRRL/ber/bp2021/Bewirtschaftungsplan_FGG_Elbe_2021.pdf&cid=14864
(last access: 27 July 2023), 2008.
Bianchi, T. S.:
Biogeochemistry of Estuaries, Oxford University Press, New York, 706 pp., https://doi.org/10.1093/oso/9780195160826.001.0001, 2007.
Boehlich, M. J. and Strotmann, T.:
The Elbe Estuary, Küste, 74, 288–306, 2008.
Boehlich, M. J. and Strotmann, T.:
Das Elbeästuar, Küste, 87, Kuratorium für Forschung im Küsteningenieurwesen (KFKI), https://doi.org/10.18171/1.087106, 2019.
Borges, A., Vanderborght, J.-P., Schiettecatte, L.-S., Gazeau, F., Ferrón-Smith, S., Delille, B., and Frankignoulle, M.:
Variability of gas transfer velocity of CO2 in a macrotidal estuary (The Scheldt), Estuaries, 27, 593–603, https://doi.org/10.1007/BF02907647, 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., Okuku, E., and Bouillon, S.:
Globally significant greenhouse-gas emissions from African inland waters, Nat. Geosci., 8, 637–642, https://doi.org/10.1038/ngeo2486, 2015.
Bouwman, A. F., Bierkens, M. F. P., Griffioen, J., Hefting, M. M., Middelburg, J. J., Middelkoop, H., and Slomp, C. P.:
Nutrient dynamics, transfer and retention along the aquatic continuum from land to ocean: towards integration of ecological and biogeochemical models, Biogeosciences, 10, 1–22, https://doi.org/10.5194/bg-10-1-2013, 2013.
Brase, L., Bange, H. W., Lendt, R., Sanders, T., and Dähnke, K.:
High Resolution Measurements of Nitrous Oxide (N2O) in the Elbe Estuary, Front. Mar. Sci., 4, 162, https://doi.org/10.3389/fmars.2017.00162, 2017a.
Brase, L., Bange, H. W., Lendt, R., Sanders, T., and Dähnke, K.: Nitrous oxide (N2O) measurements in the surface water of the Elbe Estuary in 2015, PANGAEA [data set], https://doi.org/10.1594/PANGAEA.882348, 2017b.
Brown, A. M., Bass, A. M., and Pickard, A. E.:
Anthropogenic-estuarine interactions cause disproportionate greenhouse gas production: A review of the evidence base, Mar. Pollut. Bull., 174, 113240, https://doi.org/10.1016/j.marpolbul.2021.113240, 2022.
Büttner, O., Jawitz, J. W., and Borchardt, D.:
Ecological status of river networks: stream order-dependent impacts of agricultural and urban pressures across ecoregions, Environ. Res. Lett., 15, 1040b3, https://doi.org/10.1088/1748-9326/abb62e, 2020.
Chun, Y., Kim, D., Hattori, S., Toyoda, S., Yoshida, N., Huh, J., Lim, J.-H., and Park, J.-H.:
Temperature control on wastewater and downstream nitrous oxide emissions in an urbanized river system, Water Res., 187, 116417, https://doi.org/10.1016/j.watres.2020.116417, 2020.
Clark, J. F., Schlosser, P., Simpson, H. J., Stute, M., Wanninkhof, R., and Ho, D. T.:
Relationship between gas transfer velocities and wind speeds in the tidal Hudson River determined by the dual tracer technique, in: Air–Water Gas Transfer, edited by: Jähne, B. and Monahan, E. C., AEON Verlag, Hanau, 785–800, http://www.soest.hawaii.edu/oceanography/faculty/ho/papers/Relationship_between_Gas_Transfer_Velocities_and_W.pdf (last access: 27 July 2023), 1995.
Crossland, C. J., Baird, D., Ducrotoy, J.-P., Lindeboom, H., Buddemeier, R. W., Dennison, W. C., Maxwell, B. A., Smith, S. V., and Swaney, D. P.:
The Coastal Zone – a Domain of Global Interactions, in: Coastal Fluxes in the Anthropocene: The Land-Ocean Interactions in the Coastal Zone Project of the International Geosphere-Biosphere Programme, edited by: Crossland, C. J., Kremer, H. H., Lindeboom, H. J., Marshall Crossland, J. I., and Tissier, M. D. A., Springer, Berlin, Heidelberg, https://doi.org/10.1007/3-540-27851-6_1, 1–37, 2005.
Dähnke, K., Bahlmann, E., and Emeis, K.-C.:
A nitrate sink in estuaries? An assessment by means of stable nitrate isotopes in the Elbe estuary, Limnol. Oceanogr., 53, 1504–1511, https://doi.org/10.4319/lo.2008.53.4.1504, 2008.
Dähnke, K., Sanders, T., Voynova, Y., and Wankel, S. D.:
Nitrogen isotopes reveal a particulate-matter-driven biogeochemical reactor in a temperate estuary, Biogeosciences, 19, 5879–5891, https://doi.org/10.5194/bg-19-5879-2022, 2022.
de Bie, M. J. M., Middelburg, J. J., Starink, M., and Laanbroek, H. J.:
Factors controlling nitrous oxide at the microbial community and estuarine scale, Mar. Ecol.-Prog. Ser., 240, 1–9, https://doi.org/10.3354/meps240001, 2002.
de Wilde, H. P. and de Bie, M. J.:
Nitrous oxide in the Schelde estuary: production by nitrification and emission to the atmosphere, Mar. Chem., 69, 203–216, https://doi.org/10.1016/S0304-4203(99)00106-1, 2000.
Deek, A., Dähnke, K., van Beusekom, J., Meyer, S., Voss, M., and Emeis, K.-C.:
N2 fluxes in sediments of the Elbe Estuary and adjacent coastal zones, Mar. Ecol.-Prog. Ser., 493, 9–21, https://doi.org/10.3354/meps10514, 2013.
Dijkstra, Y. M., Chant, R. J., and Reinfelder, J. R.:
Factors Controlling Seasonal Phytoplankton Dynamics in the Delaware River Estuary: an Idealized Model Study, Estuaries Coasts, 42, 1839–1857, https://doi.org/10.1007/s12237-019-00612-3, 2019.
Fabisik, F., Guieysse, B., Procter, J., and Plouviez, M.:
Nitrous oxide (N2O) synthesis by the freshwater cyanobacterium Microcystis aeruginosa, Biogeosciences, 20, 687–693, https://doi.org/10.5194/bg-20-687-2023, 2023.
FGG Elbe:
Nährstoffminderungsstrategie für die Flussgebietsgemeinschaft Elbe, Flussgebietsgemeinschaft Elbe (FGG Elbe), Magdeburg, https://www.fgg-elbe.de/files/Downloads/News/Projekte/Naehrstoffminderungsstrategie_2018_12-04.pdf
(last access: 27 July 2023), 2018.
FIS: Das Fachinfomrationssystem der FGG Elbe [data set], https://www.elbe-datenportal.de/FisFggElbe/content/start/ZurStartseite.action;jsessionid=A37EDCF5B5EC1ECB15091447E64EC53895
(last access: 21 November 2022), 2022.
Fraga, F., Ríos, A. F., Pérez, F. F., and Figueiras, F. G.:
Theoretical limits of oxygen:carbon and oxygen:nitrogen ratios during photosynthesis and mineralisation of organic matter in the sea, Sci. Mar., 62, 161–168, https://doi.org/10.3989/scimar.1998.62n1-2161, 1998.
Garnier, J., Cébron, A., Tallec, G., Billen, G., Sebilo, M., and Martinez, A.:
Nitrogen Behaviour and Nitrous Oxide Emission in the Tidal Seine River Estuary (France) as Influenced by Human Activities in the Upstream Watershed, Biogeochemistry, 77, 305–326, https://doi.org/10.1007/s10533-005-0544-4, 2006.
Gaumert, T. and Bergemann, M.:
Sauerstoffgehalt der Tideelbe – Entwicklung der kritischen Sauerstoffgehalte im Jahr 2007 und in den Vorjahren, Erörterung möglicher Ursachen und Handlungsoptionen, Flussgebietsgemeinschaft Elbe, https://www.fgg-elbe.de/files/Download-Archive/Fachberichte/Sauerstoffhaushalt/FGG_Elbe-O2-Haushalt.pdf
(last access: 27 July 2023), 2007.
Geerts, L., Wolfstein, K., Jacobs, S., van Damme, S., and Vandenbruwaene, W.:
Zonation of the TIDE estuaries, TIDE toolbox, https://www.tide-toolbox.eu/pdf/reports/Zonation_of_the_TIDE_estuaries.pdf
(last access: 27 July 2023),
2012.
Gonçalves, C., Brogueira, M. J., and Camões, M. F.:
Seasonal and tidal influence on the variability of nitrous oxide in the Tagus estuary, Portugal, Sci. Mar., 74, 57–66, https://doi.org/10.3989/scimar.2010.74s1057, 2010.
Gonçalves, C., Brogueira, M. J., and Nogueira, M.:
Tidal and spatial variability of nitrous oxide (N2O) in Sado estuary (Portugal), Estuar. Coast. Shelf S., 167, 466–474, https://doi.org/10.1016/j.ecss.2015.10.028, 2015.
Hall Jr., R. O. and Ulseth, A. J.:
Gas exchange in streams and rivers, WIREs Water, 7, e1391, https://doi.org/10.1002/wat2.1391, 2020.
Halling-Sorensen, B. and Jorgensen, S. E. (Eds.): 3. Process Chemistry and Biochemistry of Nitrification, in: Studies in Environmental Science, Vol. 54, Elsevier, https://doi.org/10.1016/S0166-1116(08)70525-9, 55–118, 1993.
Hanke, V.-R. and Knauth, H.-D.:
N2O-Gehalte in Wasser-und Luftproben aus den Bereichen der Tideelbe und der Deutschen Bucht, GKSS-Forschungszentrum, Weinheim, 1990.
Hansen, H. P. and Koroleff, F.:
Determination of nutrients, in: Methods of Seawater Analysis, edited by:
Grasshoff, K., Kremling, K., and Ehrhardt, M., John Wiley & Sons, Ltd, 159–228, https://doi.org/10.1002/9783527613984.ch10, 1999.
Harley, J. F., Carvalho, L., Dudley, B., Heal, K. V., Rees, R. M., and Skiba, U.:
Spatial and seasonal fluxes of the greenhouse gases N2O, CO2 and CH4 in a UK macrotidal estuary, Estuar. Coast. Shelf S., 153, 62–73, https://doi.org/10.1016/j.ecss.2014.12.004, 2015.
Hedges, J. I. and Keil, R. G.:
Sedimentary organic matter preservation: an assessment and speculative synthesis, Mar. Chem., 49, 81–115, https://doi.org/10.1016/0304-4203(95)00008-F, 1995.
Hein, S. S. V., Sohrt, V., Nehlsen, E., Strotmann, T., and Fröhle, P.:
Tidal Oscillation and Resonance in Semi-Closed Estuaries—Empirical Analyses from the Elbe Estuary, North Sea, Water, 13, 848, https://doi.org/10.3390/w13060848, 2021.
Hillebrand, G., Hardenbicker, P., Fischer, H., Otto, W., and Vollmer, S.:
Dynamics of total suspended matter and phytoplankton loads in the river Elbe, J. Soils Sediments, 18, 3104–3113, https://doi.org/10.1007/s11368-018-1943-1, 2018.
Hofmann, J., Behrendt, H., Gilbert, A., Janssen, R., Kannen, A., Kappenberg, J., Lenhart, H., Lise, W., Nunneri, C., and Windhorst, W.:
Catchment–coastal zone interaction based upon scenario and model analysis: Elbe and the German Bight case study, Reg. Environ. Change, 5, 54–81, https://doi.org/10.1007/s10113-004-0082-y, 2005.
HPA and Freie und Hansestadt Hamburg:
Deutsches Gewässerkundliches Jahrbuch – Elbegebiet, Teil III, Untere Elbe ab der Havelmündung – 2014, Hamburg, 2017.
Hu, M., Chen, D., and Dahlgren, R. A.:
Modeling nitrous oxide emission from rivers: a global assessment, Glob. Change Biol., 22, 3566–3582, https://doi.org/10.1111/gcb.13351, 2016.
IKSE:
Strategie zur Minderung der Nährstoffeinträge in Gewässer in der internationalen Flussgebietsgemeinschaft Elbe, Internationale Kommission zur Schutz der Elbe, Magdeburg, https://www.fgg-elbe.de/files/Downloads/News/Projekte/Naehrstoffminderungsstrategie_2018_12-04.pdf
(last access: 27 July 2023),
2018.
IPCC:
Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S. L., Péan, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I., Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K., Waterfield, T., Yelekçi, Ö., Yu, R., and Zhou, B., Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, https://doi.org/10.1017/9781009157896, 2021.
IPCC:
Climate Change 2022: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, edited by: Pörtner, H.-O., Roberts, D. C., Tignor, M. M. B., Poloczanska, E. S., Mintenbeck, K., Alegría, A., Craig, M., Langsdorf, S., Löschke, S., Möller, V., Okem, A., and Rama, B., Cambridge University Press, Cambridge, UK and New York, NY, USA, 3056 pp., https://doi.org/10.1017/9781009325844, 2022.
Ivens, W. P. M. F., Tysmans, D. J. J., Kroeze, C., Löhr, A. J., and van Wijnen, J.:
Modeling global N2O emissions from aquatic systems, Curr. Opin. Env. Sust., 3, 350–358, https://doi.org/10.1016/j.cosust.2011.07.007, 2011.
Ji, Q., Frey, C., Sun, X., Jackson, M., Lee, Y.-S., Jayakumar, A., Cornwell, J. C., and Ward, B. B.:
Nitrogen and oxygen availabilities control water column nitrous oxide production during seasonal anoxia in the Chesapeake Bay, Biogeosciences, 15, 6127–6138, https://doi.org/10.5194/bg-15-6127-2018, 2018.
Johannsen, A., Dähnke, K., and Emeis, K.:
Isotopic composition of nitrate in five German rivers discharging into the North Sea, Org. Geochem., 39, 1678–1689, https://doi.org/10.1016/j.orggeochem.2008.03.004, 2008.
Kamjunke, N., Rode, M., Baborowski, M., Kunz, J., Zehner, J., Borchardt, D., and Weitere, M.:
High irradiation and low discharge promote the dominant role of phytoplankton in riverine nutrient dynamics, Limnol. Oceanogr., 66, https://doi.org/10.1002/lno.11778, 2021.
Kappenberg, J. and Fanger, H.-U.:
Sedimenttransportgeschehen in der tidebeeinflussten Elbe, der Deutschen Bucht und in der Nordsee, GKSS-Forschungszentrum, Geesthacht, https://www.hereon.de/imperia/md/content/hzg/zentrale_einrichtungen/bibliothek/berichte/gkss_berichte_2007/gkss_2007_20.pdf
(last access: 27 July 2023), 2007.
Kassambara, A.:
ggpubr: “ggplot2” Based Publication Ready Plots, https://CRAN.R-project.org/package=ggpubr
(last access: 27 July 2023),
2023.
Kerner, M.:
Interactions between local oxygen deficiencies and heterotrophic microbial processes in the elbe estuary, Limnologica, 30, 137–143, https://doi.org/10.1016/S0075-9511(00)80008-0, 2000.
Knowles, R.:
Denitrification, Microbiol. Rev., 46, 43–70, https://doi.org/10.1128/mr.46.1.43-70.1982, 1982.
Koch, M. S., Maltby, E., Oliver, G. A., and Bakker, S. A.:
Factors controlling denitrification rates of tidal mudflats and fringing salt marshes in south-west England, Estuar. Coast. Shelf S., 34, 471–485, https://doi.org/10.1016/S0272-7714(05)80118-0, 1992.
Kroeze, C., Dumont, E., and Seitzinger, S. P.:
New estimates of global emissions of N2O from rivers and estuaries, Environ. Sci., 2, 159–165, https://doi.org/10.1080/15693430500384671, 2005.
Kroeze, C., Dumont, E., and Seitzinger, S.:
Future trends in emissions of N2O from rivers and estuaries, J. Integr. Environ. Sci., 7, 71–78, https://doi.org/10.1080/1943815X.2010.496789, 2010.
Lan, X., Dlugokencky, E. J., Mund, J. W., Crotwell, A. M., Crotwell, M. J., Moglia, E.,
Madronich, M., Neff, D., and Thoning, K. W.: Atmospheric Nitrous Oxide Dry Air
Mole Fractions from the NOAA GML Carbon Cycle Cooperative Global Air Sampling Network,
1997–2021, Version: 2022-11-21, https://doi.org/10.15138/53g1-x417 [data set], 2022.
Maavara, T., Lauerwald, R., Laruelle, G. G., Akbarzadeh, Z., Bouskill, N. J., Van Cappellen, P., and Regnier, P.:
Nitrous oxide emissions from inland waters: Are IPCC estimates too high?, Glob. Change Biol., 25, 473–488, https://doi.org/10.1111/gcb.14504, 2019.
Marzadri, A., Dee, M. M., Tonina, D., Bellin, A., and Tank, J. L.:
Role of surface and subsurface processes in scaling N2O emissions along riverine networks, P. Natl. Acad. Sci. USA, 114, 4330–4335, https://doi.org/10.1073/pnas.1617454114, 2017.
Middelburg, J. J. and Herman, P. M. J.:
Organic matter processing in tidal estuaries, Mar. Chem., 106, 127–147, https://doi.org/10.1016/j.marchem.2006.02.007, 2007.
Middelburg, J. J. and Nieuwenhuize, J.:
Uptake of dissolved inorganic nitrogen in turbid, tidal estuaries, Mar. Ecol. Prog. Ser., 192, 79–88, https://doi.org/10.3354/meps192079, 2000.
Murray, R. H., Erler, D. V., and Eyre, B. D.:
Nitrous oxide fluxes in estuarine environments: response to global change, Glob. Change Biol., 21, 3219–3245, https://doi.org/10.1111/gcb.12923, 2015.
Nevison, C., Butler, J. H., and Elkins, J. W.:
Global distribution of N2O and the ΔN2O-AOU yield in the subsurface ocean, Global Biogeochem. Cy., 17, 1119, https://doi.org/10.1029/2003GB002068, 2003.
Nightingale, P. D., Malin, G., Law, C. S., Watson, A. J., Liss, P. S., Liddicoat, M. I., Boutin, J., and Upstill-Goddard, R. C.:
In situ evaluation of air–sea gas exchange parameterizations using novel conservative and volatile tracers, Global Biogeochem. Cy., 14, 373–387, https://doi.org/10.1029/1999GB900091, 2000.
Nixon, S. W., Ammerman, J. W., Atkinson, L. P., Berounsky, V. M., Billen, G., Boicourt, W. C., Boynton, W. R., Church, T. M., Ditoro, D. M., Elmgren, R., Garber, J. H., Giblin, A. E., Jahnke, R. A., Owens, N. J. P., Pilson, M. E. Q., and Seitzinger, S. P.:
The fate of nitrogen and phosphorus at the land–sea margin of the North Atlantic Ocean, Biogeochemistry, 35, 141–180, https://doi.org/10.1007/BF02179826, 1996.
Norbisrath, M., Pätsch, J., Dähnke, K., Sanders, T., Schulz, G., van Beusekom, J. E. E., and Thomas, H.:
Metabolic alkalinity release from large port facilities (Hamburg, Germany) and impact on coastal carbon storage, Biogeosciences, 19, 5151–5165, https://doi.org/10.5194/bg-19-5151-2022, 2022.
Pätsch, J., Serna, A., Dähnke, K., Schlarbaum, T., Johannsen, A., and Emeis, K.-C.:
Nitrogen cycling in the German Bight (SE North Sea) – Clues from modelling stable nitrogen isotopes, Cont. Shelf Res., 30, 203–213, https://doi.org/10.1016/j.csr.2009.11.003, 2010.
Pind, A., Risgaard-Petersen, N., and Revsbech, N. P.:
Denitrification and microphytobenthic
Quick, A. M., Reeder, W. J., Farrell, T. B., Tonina, D., Feris, K. P., and Benner, S. G.:
Nitrous oxide from streams and rivers: A review of primary biogeochemical pathways and environmental variables, Earth-Sci. Rev., 191, 224–262, https://doi.org/10.1016/j.earscirev.2019.02.021, 2019.
Quiel, K., Becker, A., Kirchesch, V., Schöl, A., and Fischer, H.:
Influence of global change on phytoplankton and nutrient cycling in the Elbe River, Reg. Environ. Change, 11, 405–421, https://doi.org/10.1007/s10113-010-0152-2, 2011.
Radach, G. and Pätsch, J.:
Variability of continental riverine freshwater and nutrient inputs into the North Sea for the years 1977–2000 and its consequences for the assessment of eutrophication, Estuaries Coasts, 30, 66–81, https://doi.org/10.1007/BF02782968, 2007.
Reading, M. J., Tait, D. R., Maher, D. T., Jeffrey, L. C., Looman, A., Holloway, C., Shishaye, H. A., Barron, S., and Santos, I. R.:
Land use drives nitrous oxide dynamics in estuaries on regional and global scales, Limnol. Oceanogr., 65, 1903–1920, https://doi.org/10.1002/lno.11426, 2020.
Redfield, A. C., Ketchum, B. H., and Richards, F. A.:
The influence of organisms on the composition of sea-water, in: The composition of seawater: Comparative and descriptive oceanography, The sea: ideas and observations on progress in the study of the seas,
2. Interscience Publishers, New York, ISBN 9780674017283, 554 pp., 1963.
Rewrie, L. C. V., Voynova, Y. G., van Beusekom, J. E. E., Sanders, T., Körtzinger, A., Brix, H., Ollesch, G., and Baschek, B.:
Significant shifts in inorganic carbon and ecosystem state in a temperate estuary (1985–2018), Limnol. Oceanogr., https://doi.org/10.1002/lno.12395, online first, 2023.
Rhee, T. S., Kettle, A. J., and Andreae, M. O.:
Methane and nitrous oxide emissions from the ocean: A reassessment using basin-wide observations in the Atlantic, J. Geophys. Res.-Atmos., 114, D12304, https://doi.org/10.1029/2008JD011662, 2009.
Robinson, A. D., Nedwell, D. B., Harrison, R. M., and Ogilvie, B. G.:
Hypernutrified estuaries as sources of N2O emission to the atmosphere: the estuary of the River Colne, Essex, UK, Mar. Ecol.-Prog. Ser., 164, 59–71, https://doi.org/10.3354/meps164059, 1998.
Rosamond, M. S., Thuss, S. J., and Schiff, S. L.:
Dependence of riverine nitrous oxide emissions on dissolved oxygen levels, Nat. Geosci., 5, 715–718, https://doi.org/10.1038/ngeo1556, 2012.
Rosenhagen, G., Schatzmann, M., and Schrön, A.:
Das Klima der Metropolregion auf Grundlage meteorologischer Messungen und Beobachtungen, in: Klimabericht für die Metropolregion Hamburg, edited by: von Storch, H. and Claussen, M., Springer, Berlin, Heidelberg, 19–59, https://doi.org/10.1007/978-3-642-16035-6_2, 2011.
Rosentreter, J. A., Wells, N. S., Ulseth, A. J., and Eyre, B. D.:
Divergent Gas Transfer Velocities of CO2, CH4, and N2O Over Spatial and Temporal Gradients in a Subtropical Estuary, J. Geophys. Res.-Biogeo., 126, e2021JG006270, https://doi.org/10.1029/2021JG006270, 2021.
Sanders, T., Schöl, A., and Dähnke, K.:
Hot Spots of Nitrification in the Elbe Estuary and Their Impact on Nitrate Regeneration, Estuaries Coasts, 41, 128–138, https://doi.org/10.1007/s12237-017-0264-8, 2018.
Scharfe, M., Callies, U., Blöcker, G., Petersen, W., and Schroeder, F.:
A simple Lagrangian model to simulate temporal variability of algae in the Elbe River, Ecol. Model., 220, 2173–2186, https://doi.org/10.1016/j.ecolmodel.2009.04.048, 2009.
Schleswig-Holstein and Hamburg:
Mittlere Windgeschwindigkeit (1986–2015)* | Norddeutscher Klimamonitor, https://www.norddeutscher-klimamonitor.de/klima/1986-2015/jahr/mittlere-windgeschwindigkeit/schleswig-holstein-hamburg/coastdat-1.html (last access: 27 April 2023), 2023.
Schoer, J. H.:
Determination of the origin of suspended matter and sediments in the Elbe estuary using natural tracers, Estuaries, 13, 161–172, https://doi.org/10.2307/1351585, 1990.
Schöl, A., Hein, B., Wyrwa, J., and Kirchesch, V.:
Modelling Water Quality in the Elbe and its Estuary – Large Scale and Long Term Applications with Focus on the Oxygen Budget of the Estuary, Küste, 203–232, 2014.
Schroeder, F.:
Water quality in the Elbe estuary: Significance of different processes for the oxygen deficit at Hamburg, Environ. Model. Assess., 2, 73–82, https://doi.org/10.1023/A:1019032504922, 1997.
Sharma, N., Flynn, E. D., Catalano, J. G., and Giammar, D. E.:
Copper availability governs nitrous oxide accumulation in wetland soils and stream sediments, Geochim. Cosmochim. Ac., 327, 96–115, https://doi.org/10.1016/j.gca.2022.04.019, 2022.
Siedler, G. and Peters, H.:
Properties of sea water, Physical properties, in: Oceanography, vol. V/3a, edited by: Sündermann, J., Springer, Berlin, Germany, 233–264, ISBN 3-540-15092-7, 1986.
Silvennoinen, H., Hietanen, S., Liikanen, A., Stange, C. F., Russow, R., Kuparinen, J., and Martikainen, P. J.:
Denitrification in the River Estuaries of the Northern Baltic Sea, AMBIO J. Hum. Environ., 36, 134–140, https://doi.org/10.1579/0044-7447(2007)36[134:DITREO]2.0.CO;2, 2007.
Smith, R. L. and Böhlke, J. K.:
Methane and nitrous oxide temporal and spatial variability in two midwestern USA streams containing high nitrate concentrations, Sci. Total Environ., 685, 574–588, https://doi.org/10.1016/j.scitotenv.2019.05.374, 2019.
Sommerfield, C. K. and Wong, K.-C.:
Mechanisms of sediment flux and turbidity maintenance in the Delaware Estuary, J. Geophys. Res.-Oceans, 116, C01005, https://doi.org/10.1029/2010JC006462, 2011.
Tang, W., Tracey, J. C., Carroll, J., Wallace, E., Lee, J. A., Nathan, L., Sun, X., Jayakumar, A., and Ward, B. B.:
Nitrous oxide production in the Chesapeake Bay, Limnol. Oceanogr., 67, 2101–2116, https://doi.org/10.1002/lno.12191, 2022.
R-Core Team: The R Stats Package, Version 4.0.2:
https://www.rdocumentation.org/packages/stats/versions/3.6.2/topics/prcomp (last access: 29 January 2021), 2021.
Tian, H., Xu, R., Canadell, J. G., Thompson, R. L., Winiwarter, W., Suntharalingam, P., Davidson, E. A., Ciais, P., Jackson, R. B., Janssens-Maenhout, G., Prather, M. J., Regnier, P., Pan, N., Pan, S., Peters, G. P., Shi, H., Tubiello, F. N., Zaehle, S., Zhou, F., Arneth, A., Battaglia, G., Berthet, S., Bopp, L., Bouwman, A. F., Buitenhuis, E. T., Chang, J., Chipperfield, M. P., Dangal, S. R. S., Dlugokencky, E., Elkins, J. W., Eyre, B. D., Fu, B., Hall, B., Ito, A., Joos, F., Krummel, P. B., Landolfi, A., Laruelle, G. G., Lauerwald, R., Li, W., Lienert, S., Maavara, T., MacLeod, M., Millet, D. B., Olin, S., Patra, P. K., Prinn, R. G., Raymond, P. A., Ruiz, D. J., van der Werf, G. R., Vuichard, N., Wang, J., Weiss, R. F., Wells, K. C., Wilson, C., Yang, J., and Yao, Y.:
A comprehensive quantification of global nitrous oxide sources and sinks, Nature, 586, 248–256, https://doi.org/10.1038/s41586-020-2780-0, 2020.
US EPA:
Volunteer Estuary Monitoring: A Methods Manual, United States Environmental Protection Agency (EPA), EPA-842-B-06-003, 2006.
van Beusekom, J. E. E., Carstensen, J., Dolch, T., Grage, A., Hofmeister, R., Lenhart, H., Kerimoglu, O., Kolbe, K., Pätsch, J., Rick, J., Rönn, L., and Ruiter, H.:
Wadden Sea Eutrophication: Long-Term Trends and Regional Differences, Front. Mar. Sci., 6, 370, https://doi.org/10.3389/fmars.2019.00370, 2019.
Walter, S., Bange, H. W., and Wallace, D. W. R.:
Nitrous oxide in the surface layer of the tropical North Atlantic Ocean along a west to east transect, Geophys. Res. Lett., 31, L23S07, https://doi.org/10.1029/2004GL019937, 2004.
Wanninkhof, R.:
Relationship between wind speed and gas exchange over the ocean, J. Geophys. Res.-Oceans, 97, 7373–7382, https://doi.org/10.1029/92JC00188, 1992.
Weiss, R. F.:
The solubility of nitrogen, oxygen and argon in water and seawater, Deep Sea Res. Oceanogr. Abstr., 17, 721–735, https://doi.org/10.1016/0011-7471(70)90037-9, 1970.
Weiss, R. F. and Price, B. A.:
Nitrous oxide solubility in water and seawater, Mar. Chem., 8, 347–359, https://doi.org/10.1016/0304-4203(80)90024-9, 1980.
Wells, N. S., Maher, D. T., Erler, D. V., Hipsey, M., Rosentreter, J. A., and Eyre, B. D.:
Estuaries as Sources and Sinks of N2O Across a Land Use Gradient in Subtropical Australia, Global Biogeochem. Cy., 32, 877–894, https://doi.org/10.1029/2017GB005826, 2018.
Wertz, S., Goyer, C., Burton, D. L., Zebarth, B. J., and Chantigny, M. H.:
Processes contributing to nitrite accumulation and concomitant N2O emissions in frozen soils, Soil Biol. Biochem., 126, 31–39, https://doi.org/10.1016/j.soilbio.2018.08.001, 2018.
Winterwerp, J. C. and Wang, Z. B.:
Man-induced regime shifts in small estuaries – I: theory, Ocean Dynam., 63, 1279–1292, https://doi.org/10.1007/s10236-013-0662-9, 2013.
WMO (World Meteorological Organization):
Scientific Assessment of Ozone Depletion: 2018, Global Ozone Research and Monitoring Project – Report No. 58, 588 pp., Geneva, Switzerland, 2018.
Wolfstein, K. and Kies, L.:
Composition of suspended participate matter in the Elbe estuary: Implications for biological and transportation processes, Dtsch. Hydrogr. Z., 51, 453–463, https://doi.org/10.1007/BF02764166, 1999.
Wrage, N., Velthof, G. L., van Beusichem, M. L., and Oenema, O.:
The role of nitrifier denitrification in the production of nitrous oxide, Soil Biol. Biochem., 33, 1723–1732, https://doi.org/10.1016/S0038-0717(01)00096-7, 2001.
Yevenes, M. A., Bello, E., Sanhueza-Guevara, S., and Farías, L.:
Spatial Distribution of Nitrous Oxide (N2O) in the Reloncaví Estuary–Sound and Adjacent Sea (41∘–43∘ S), Chilean Patagonia, Estuaries Coasts, 40, 807–821, https://doi.org/10.1007/s12237-016-0184-z, 2017.
Zander, F., Heimovaara, T., and Gebert, J.:
Spatial variability of organic matter degradability in tidal Elbe sediments, J. Soils Sediments, 20, 2573–2587, https://doi.org/10.1007/s11368-020-02569-4, 2020.
Zander, F., Groengroeft, A., Eschenbach, A., Heimovaara, T. J., and Gebert, J.:
Organic matter pools in sediments of the tidal Elbe river, Limnologica, 96, 125997, https://doi.org/10.1016/j.limno.2022.125997, 2022.
ZDM:
Abfluss – Neu Darchau, Wasserstraßen- und Schifffahrtsamt Elbe [data set], https://www.kuestendaten.de/DE/Services/Messreihen_Dateien_Download/Download_Zeitreihen_node.html
(last access: 11 May 2023), 2022.
Short summary
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.
Nitrous oxide (N2O) is an important greenhouse gas. However, N2O emissions from estuaries...
Altmetrics
Final-revised paper
Preprint