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  • 1.
    Almeida, Nazare da Silva
    et al.
    Univ Sao Paulo, Brazil.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Umea Univ, Sweden.
    Teixeira, C. A. S.
    Univ Sao Paulo, Brazil.
    Bertassoli, D. J. Jr.
    Univ Sao Paulo, Brazil.
    Furukawa, L. Y.
    Univ Sao Paulo, Brazil.
    Pelissari, M.
    Univ Sao Paulo, Brazil.
    Sawakuchi, A. O.
    Univ Sao Paulo, Brazil.
    Incubation experiments to constrain the production of methane and carbon dioxide in organic-rich shales of the Permian Irati Formation, Parana Basin2020Ingår i: Marine and Petroleum Geology, ISSN 0264-8172, E-ISSN 1873-4073, Vol. 112, artikel-id UNSP 104039Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Permian Irati Formation in Brazil hosts organic-rich shales and heavy hydrocarbons suitable for biogenic production of methane (CH4) and carbon dioxide (CO2). In this study, shale samples from the irati Formation were used in laboratory incubation experiments performed under different temperatures (22 degrees C, 50 degrees C, 70 degrees C and 80 degrees C) to evaluate the generation of CH4 and CO2 under thermal conditions compatible with biodegradation in shallow gas systems (amp;lt; 80 degrees C). Despite our laboratory experiments do not represent natural subsurface temperature conditions, it is observed that the concentrations of CH4 and CO2 increase when shale samples are incubated under temperature higher than 22 degrees C. Samples incubated at 80 degrees C presented a maximum CH4 yield of 2.45 ml/t.d (milliliter per ton of shale per day) compared to 0,49 ml/t.d at 22 degrees C, 1.75 ml/t.d at 50 degrees C and 2.09 ml/t.d at 70 degrees C. The same trend of increasing production rates with higher temperatures was observed for CO2, with maximum potential production observed under a laboratory temperature of 80 degrees C, reaching 23.47 ml/t.d. Stable carbon isotopes (delta C-13) on CH4 and CO2 suggest a mixture of thermogenic and secondary microbial gas. However, the measured CH4 and CO2 can be generated through methanogenic degradation of heavy hydrocarbons present in the studied shales, difficulting the use of carbon isotope composition to discriminate between biogenic and thermogenic gases. The studied shale samples showed significant differences in CH4 and CO2 production rates, which are possibly related to the major elements composition of the mineral matrix. Higher CH4 and CO2 production rates occurred in samples with higher amount of sulfur. Besides sulfur, we highlight that others soluble elements in the mineral matrix, such as Ca and Mg, can play an important role for the generation of biogenic CH4 and CO2. The present work intends to alert for the importance of thermal conditions as well as the geochemical composition of the mineral matrix to build conceptual models about shallow gas systems, acting on organic-rich shales in sedimentary basins.

  • 2.
    Bastviken, David
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Treat, Claire C.
    Helmholtz Ctr Polar & Marine Res, Germany.
    Pangala, Sunitha Rao
    Univ Lancaster, England.
    Gauci, Vincent
    Univ Birmingham, England; Univ Birmingham, England.
    Enrich Prast, Alex
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Fed Univ Sao Paulo IMar UNIFESP, Brazil; Univ Fed Rio De Janeiro, Brazil.
    Karlson, Martin
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Centrum för klimatpolitisk forskning, CSPR.
    Gålfalk, Magnus
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Brandini Romano, Mariana
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    The importance of plants for methane emission at the ecosystem scale2023Ingår i: Aquatic Botany, ISSN 0304-3770, E-ISSN 1879-1522, Vol. 184, artikel-id 103596Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Methane (CH4), one of the key long-lived atmospheric greenhouse gases, is primarily produced from organic matter. Accordingly, net primary production of organic matter sets the boundaries for CH4 emissions. Plants, being dominant primary producers, are thereby indirectly sustaining most global CH4 emissions, albeit with delays in time and with spatial offsets between plant primary production and subsequent CH4 emission. In addition, plant communities can enhance or hamper ecosystem production, oxidation, and transport of CH4 in multiple ways, e.g., by shaping carbon, nutrient, and redox gradients, and by representing a physical link be-tween zones with extensive CH4 production in anoxic sediments or soils and the atmosphere. This review focuses on how plants and other primary producers influence CH4 emissions with the consequences at ecosystem scales. We outline mechanisms of interactions and discuss flux regulation, quantification, and knowledge gaps across multiple ecosystem examples. Some recently proposed plant-related ecosystem CH4 fluxes are difficult to reconcile with the global atmospheric CH4 budget and the enigmas related to these fluxes are highlighted. Overall, ecosystem CH4 emissions are strongly linked to primary producer communities, directly or indirectly, and properly quantifying magnitudes and regulation of these links are key to predicting future CH4 emissions in a rapidly changing world.

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  • 3.
    Bertassoli, Dailson J. Jr.
    et al.
    Univ Sao Paulo, Brazil; Univ Sao Paulo, Brazil.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    de Araujo, Kleiton R.
    Fed Univ Para, Brazil.
    de Camargo, Marcelo G. P.
    Univ Sao Paulo, Brazil.
    Alem, Victor A. T.
    Univ Sao Paulo, Brazil.
    Pereira, Tatiana S.
    Fed Univ Para, Brazil.
    Krusche, Alex V
    Univ Sao Paulo, Brazil.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Richey, Jeffrey E.
    Univ Sao Paulo, Brazil; Univ Washington, WA 98195 USA.
    Sawakuchi, Andre O.
    Univ Sao Paulo, Brazil.
    How green can Amazon hydropower be?: Net carbon emission from the largest hydropower plant in Amazonia2021Ingår i: Science Advances, E-ISSN 2375-2548, Vol. 7, nr 26, artikel-id eabe1470Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The current resurgence of hydropower expansion toward tropical areas has been largely based on run-of-the-river (ROR) dams, which are claimed to have lower environmental impacts due to their smaller reservoirs. The Belo Monte dam was built in Eastern Amazonia and holds the largest installed capacity among ROR power plants worldwide. Here, we show that postdamming greenhouse gas (GHG) emissions in the Belo Monte area are up to three times higher than preimpoundment fluxes and equivalent to about 15 to 55 kg CO(2)eq MWh(-1). Since per-area emissions in Amazonian reservoirs are significantly higher than global averages, reducing flooded areas and prioritizing the power density of hydropower plants seem to effectively reduce their carbon footprints. Nevertheless, total GHG emissions are substantial even from this leading-edge ROR power plant. This argues in favor of avoiding hydropower expansion in Amazonia regardless of the reservoir type.

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  • 4.
    Bertoluci, Jaime
    et al.
    Univ Sao Paulo, Brazil.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Ortiz, Carolina
    Univ Sao Paulo, Brazil.
    Brassaloti, Ricardo Augusto
    Univ Sao Paulo, Brazil.
    Ribeiro-Junior, Jose Wagner
    Univ Estadual Paulista, Brazil.
    Famelli, Shirley
    Univ Sao Paulo, Brazil.
    Anuran fauna of the Parque Estadual Carlos Botelho - Nficleo Sete Barras, southeastern Brazil: species composition, use of breeding sites, and seasonal patterns of breeding activity2021Ingår i: Biota neopropica, ISSN 1678-6424, E-ISSN 1676-0603, Vol. 21, nr 1, artikel-id e20201082Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The goal of this work was to study the species composition, the use of breeding sites, and the seasonal patterns of breeding activity of the anuran fauna from Parque Estadual Carlos Botelho - Nucleo Sete Barras, state of Sao Paulo, southeastern Brazil. Fieldwork was carried out from September 2005 to October 2007 through two main methods: active visual search inside a 10 ha- permanent plot and aural and visual search in seven previously selected aquatic breeding habitats. Species richness was related to the sampling effort by means of species accumulation curve and through non-parametric estimators. Thirty-three species distributed in 12 families were recorded, from which 69% are endemic to the Atlantic Forest. Trachycephalus mesophaeus represents a new record for the park. Cycloramphus lutzorum is included as Data Deficient in the IUCN list. The species accumulation curve did not stabilize, showing some tendency to rise. The use of breeding sites by 20 species was compared using cluster analysis, which revealed two major groups: the first with five species (two habitat generalists and three stream specialists) and the second composed by the other species (with different reproductive modes associated with flooded environments). The breeding period of most species was associated to the rainy season (October to February), and only Scinax hayii showed continuous breeding activity during the entire period of study.

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  • 5.
    Covey, Kristofer
    et al.
    Skidmore Coll, NY 12866 USA.
    Soper, Fiona
    McGill Univ, Canada; McGill Univ, Canada.
    Pangala, Sunitha
    Univ Lancaster, England.
    Bernardino, Angelo
    Univ Fed Espirito Santo, Brazil.
    Pagliaro, Zoe
    Skidmore Coll, NY 12866 USA.
    Basso, Luana
    Natl Inst Space Res, Brazil.
    Cassol, Henrique
    Natl Inst Space Res, Brazil.
    Fearnside, Philip
    Natl Inst Res Amazonia Inst Nacl Pesquisas, Brazil.
    Navarrete, Diego
    Nature Conservancy, Colombia.
    Novoa, Sidney
    Asociac Conservac Cuenca Amazon, Peru.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Lovejoy, Thomas
    Department of Environmental Science and Policy, George Mason University, Fairfax, VA, United States.
    Marengo, Jose
    George Mason Univ, VA 22030 USA.
    Peres, Carlos A.
    Natl Ctr Monitoring & Early Warning Nat Disasters, Brazil; Univ East Anglia, England.
    Baillie, Jonathan
    Natl Geog Soc, DC USA.
    Bernasconi, Paula
    Inst Ctr Vida ICV, Brazil.
    Camargo, Jose
    National Institute for Research in Amazonia (Instituto Nacional de Pesquisas da Amazônia), Manaus, Brazil.
    Freitas, Carolina
    Inst Nacl Pesquisas Espaciais INPE, Brazil.
    Hoffman, Bruce
    Amazon Conservat Team Suriname Program, Suriname.
    Nardoto, Gabriela B.
    Univ Brasilia, Brazil.
    Nobre, Ismael
    Univ Estadual Campinas, Brazil.
    Mayorga, Juan
    Univ Calif Santa Barbara, CA 93106 USA.
    Mesquita, Rita
    National Institute for Research in Amazonia (Instituto Nacional de Pesquisas da Amazônia), Manaus, Brazil.
    Pavan, Silvia
    Museu Paraense Emilio Goeldi, Brazil.
    Pinto, Flavia
    Nature Conservancy, Brazil.
    Rocha, Flavia
    Fed Rural Univ Rio Janeiro, Brazil.
    de Assis Mello, Ricardo
    World Wide Fund Nat WWF, Brazil.
    Thuault, Alice
    Inst Ctr Vida ICV, Brazil.
    Bahl, Alexis Anne
    Natl Geog Soc, DC USA.
    Elmore, Aurora
    Natl Geog Soc, DC USA.
    Carbon and Beyond: The Biogeochemistry of Climate in a Rapidly Changing Amazon2021Ingår i: Frontiers in Forests and Gobal Change, ISSN 2624-893X, Vol. 4, artikel-id 618401Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The Amazon Basin is at the center of an intensifying discourse about deforestation, land-use, and global change. To date, climate research in the Basin has overwhelmingly focused on the cycling and storage of carbon (C) and its implications for global climate. Missing, however, is a more comprehensive consideration of other significant biophysical climate feedbacks [i.e., CH4, N2O, black carbon, biogenic volatile organic compounds (BV0Cs), aerosols, evapotranspiration, and albedo] and their dynamic responses to both localized (fire, land-use change, infrastructure development, and storms) and global (warming, drying, and some related to El Nino or to warming in the tropical Atlantic) changes. Here, we synthesize the current understanding of (1) sources and fluxes of all major forcing agents, (2) the demonstrated or expected impact of global and local changes on each agent, and (3) the nature, extent, and drivers of anthropogenic change in the Basin. We highlight the large uncertainty in flux magnitude and responses, and their corresponding direct and indirect effects on the regional and global climate system. Despite uncertainty in their responses to change, we conclude that current warming from non-CO2 agents (especially CH4 and N2O) in the Amazon Basin largely offsets- and most likely exceeds-the climate service provided by atmospheric CO2 uptake. We also find that the majority of anthropogenic impacts act to increase the radiative forcing potential of the Basin. Given the large contribution of less-recognized agents (e.g., Amazonian trees alone emit similar to 3.5% of all global CH4), a continuing focus on a single metric (i.e., C uptake and storage) is incompatible with genuine efforts to understand and manage the biogeochemistry of climate in a rapidly changing Amazon Basin.

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  • 6.
    de Araujo, Kleiton R.
    et al.
    Univ Fed Para, Brazil.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Univ Sao Paulo, Brazil; Umea Univ, Sweden.
    Bertassoli, Dailson J. Jr.
    Univ Sao Paulo, Brazil.
    Sawakuchi, Andre O.
    Univ Fed Para, Brazil; Univ Sao Paulo, Brazil.
    da Silva, Karina D.
    Univ Fed Para, Brazil; Univ Fed Para, Brazil.
    Vieira, Thiago B.
    Univ Fed Para, Brazil; Univ Fed Para, Brazil.
    Ward, Nicholas D.
    Pacific Northwest Natl Lab, WA 98382 USA; Univ Washington, WA 98195 USA.
    Pereira, Tatiana S.
    Univ Fed Para, Brazil; Univ Fed Para, Brazil.
    Carbon dioxide (CO2) concentrations and emission in the newly constructed Belo Monte hydropower complex in the Xingu River, Amazonia2019Ingår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 16, nr 18, s. 3527-3542Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Belo Monte hydropower complex located in the Xingu River is the largest run-of-the-river (ROR) hydroelectric system in the world and has one of the highest energy production capacities among dams. Its construction received significant media attention due to its potential social and environmental impacts. It is composed of two ROR reservoirs: the Xingu Reservoir (XR) in the Xingus main branch and the Intermediate Reservoir (IR), an artificial reservoir fed by waters diverted from the Xingu River with longer water residence time compared to XR. We aimed to evaluate spatiotemporal variations in CO2 partial pressure (pCO(2)) and CO2 fluxes (FCO2) during the first 2 years after the Xingu River impoundment under the hypothesis that each reservoir has contrasting FCO2 and pCO(2) as vegetation clearing reduces flooded area emissions. Time of the year had a significant influence on pCO(2) with the highest average values observed during the high-water season. Spatial heterogeneity throughout the entire study area was observed for pCO(2) during both low-and high-water seasons. FCO2, on the other hand, only showed significant spatial heterogeneity during the high-water period. FCO2 (0.90 +/- 0.47 and 1.08 +/- 0.62 mu mol m(2) d(-1) for XR and IR, respectively) and pCO(2) (1647 +/- 698 and 1676 +/- 323 mu atm for XR and IR, respectively) measured during the high-water season were on the same order of magnitude as previous observations in other Amazonian clearwater rivers unaffected by impoundment during the same season. In contrast, during the low-water season FCO2 (0.69 +/- 0.28 and 7.32 +/- 4.07 mu mol m(2) d(-1) for XR and IR, respectively) and pCO(2) (839 +/- 646 and 1797 +/- 354 mu atm for XR and IR, respectively) in IR were an order of magnitude higher than literature FCO2 observations in clearwater rivers with naturally flowing waters. When CO2 emissions are compared between reservoirs, IR emissions were 90% higher than values from the XR during low-water season, reinforcing the clear influence of reservoir characteristics on CO2 emissions. Based on our observations in the Belo Monte hydropower complex, CO2 emissions from ROR reservoirs to the atmosphere are in the range of natural Amazonian rivers. However, the associated reservoir (IR) may exceed natural river emission rates due to the preimpounding vegetation influence. Since many reservoirs are still planned to be constructed in the Amazon and throughout the world, it is critical to evaluate the implications of reservoir traits on FCO2 over their entire life cycle in order to improve estimates of CO2 emissions per kilowatt for hydropower projects planned for tropical rivers.

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  • 7.
    Häggi, C.
    et al.
    Royal Netherlands Inst Sea Res, Netherlands; Univ Bremen, Germany; Swiss Fed Inst Technol, Switzerland.
    Hopmans, E. C.
    Royal Netherlands Inst Sea Res, Netherlands.
    Schefuss, E.
    Univ Bremen, Germany.
    Sawakuchi, A. O.
    Univ Sao Paulo, Brazil.
    Schreuder, L. T.
    Royal Netherlands Inst Sea Res, Netherlands.
    Bertassoli, D. J. Jr Jr
    Univ Sao Paulo, Brazil.
    Chiessi, C. M.
    Univ Sao Paulo, Brazil.
    Mulitza, S.
    Univ Bremen, Germany.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Baker, P. A.
    Duke Univ, NC USA.
    Schouten, S.
    Royal Netherlands Inst Sea Res, Netherlands; Univ Utrecht, Netherlands.
    Negligible Quantities of Particulate Low-Temperature Pyrogenic Carbon Reach the Atlantic Ocean via the Amazon River2021Ingår i: Global Biogeochemical Cycles, ISSN 0886-6236, E-ISSN 1944-9224, Vol. 35, nr 9, artikel-id e2021GB006990Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Particulate pyrogenic carbon (PyC) transported by rivers and aerosols, and deposited in marine sediments, is an important part of the carbon cycle. The chemical composition of PyC is temperature dependent and levoglucosan is a source-specific burning marker used to trace low-temperature PyC. Levoglucosan associated to particulate material has been shown to be preserved during riverine transport and marine deposition in high- and mid-latitudes, but it is yet unknown if this is also the case for (sub)tropical areas, where 90% of global PyC is produced. Here, we investigate transport and deposition of levoglucosan in suspended and riverbed sediments from the Amazon River system and adjacent marine deposition areas. We show that the Amazon River exports negligible amounts of levoglucosan and that concentrations in sediments from the main Amazon tributaries are not related to long-term mean catchment-wide fire activity. Levoglucosan concentrations in marine sediments offshore the Amazon Estuary are positively correlated to total organic content regardless of terrestrial or marine origin, supporting the notion that association of suspended or dissolved PyC to biogenic particles is critical in the preservation of PyC. We estimate that 0.5-10 x 10(6) g yr(-1) of levoglucosan is exported by the Amazon River. This represents only 0.5-10 ppm of the total exported PyC and thereby an insignificant fraction, indicating that riverine derived levoglucosan and low-temperature PyC in the tropics are almost completely degraded before deposition. Hence, we suggest caution in using levoglucosan as tracer for past fire activity in tropical settings near rivers.

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  • 8.
    Pajala, Gustav
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Rudberg, David
    Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutionen för tema, Tema Miljöförändring.
    Gålfalk, Magnus
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Melack, John Michael
    University of California, Santa Barbara, CA, United States.
    Macintyre, Sally
    University of California, Santa Barbara, CA, United States.
    Karlsson, Jan
    Umeå University, Umeå, Sweden.
    Sawakuchi, Henrique Oliveira
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Schenk, Jonathan
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sieczko, Anna Katarzyna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologisk och miljövetenskaplig modellering. Linköpings universitet, Tekniska fakulteten.
    Sundgren, Ingrid
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Nguyen, Thanh Duc
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Source data for ” Higher apparent gas transfer velocities for CO2 compared to CH4 in small lakes”2023Dataset
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  • 9.
    Pajala, Gustav
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Rudberg, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Gålfalk, Magnus
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Melack, John Michael
    Univ Calif Santa Barbara, CA 93117 USA; Univ Calif Santa Barbara, CA 93106 USA.
    Macintyre, Sally
    Univ Calif Santa Barbara, CA 93117 USA; Univ Calif Santa Barbara, CA 93106 USA; Univ Calif Santa Barbara, CA 93117 USA.
    Karlsson, Jan
    Umea Univ, Sweden.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Schenk, Jonathan
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sieczko, Anna
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sundgren, Ingrid
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Nguyen, Thanh Duc
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Higher Apparent Gas Transfer Velocities for CO2 Compared to CH4 in Small Lakes2023Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 57, nr 23, s. 8578-8587Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Highergas transfer velocities for CO2 than CH4 inlakes challenge previous results and commonly made assumptionsand highlight the importance of gas-specific transport in aquaticgreenhouse gas exchange. Large greenhousegas emissions occur via the release of carbondioxide (CO2) and methane (CH4) from the surfacelayer of lakes. Such emissions are modeled from the air-watergas concentration gradient and the gas transfer velocity (k). The links between k and the physicalproperties of the gas and water have led to the development of methodsto convert k between gases through Schmidt numbernormalization. However, recent observations have found that such normalizationof apparent k estimates from field measurements canyield different results for CH4 and CO2. Weestimated k for CO2 and CH4 from measurements of concentration gradients and fluxes in fourcontrasting lakes and found consistently higher (on an average 1.7times) normalized apparent k values for CO2 than CH4. From these results, we infer that several gas-specificfactors, including chemical and biological processes within the watersurface microlayer, can influence apparent k estimates.We highlight the importance of accurately measuring relevant air-watergas concentration gradients and considering gas-specific processeswhen estimating k.

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  • 10.
    Pajala, Gustav
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique Oliveira
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Rudberg, David
    Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutionen för tema, Tema Miljöförändring.
    Schenk, Jonathan
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sieczko, Anna Katarzyna
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Seekell, David
    Sundgren, Ingrid
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Nguyen, Thanh Duc
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Tekniska fakulteten.
    Karlsson, Jan
    Umeå University.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Source data for “The effects of water column dissolved oxygen concentrations on lake methane emissions: Results from a whole-lake oxygenation experiment”2022Dataset
    Ladda ner fulltext (xlsx)
    dataset version 2.0
  • 11.
    Pajala, Gustav
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Rudberg, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Schenk, Jonathan
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sieczko, Anna
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Gålfalk, Magnus
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Seekell, David
    Umea Univ, Sweden.
    Sundgren, Ingrid
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Nguyen, Thanh Duc
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Karlsson, Jan
    Umea Univ, Sweden.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    The Effects of Water Column Dissolved Oxygen Concentrations on Lake Methane Emissions-Results From a Whole-Lake Oxygenation Experiment2023Ingår i: Journal of Geophysical Research - Biogeosciences, ISSN 2169-8953, E-ISSN 2169-8961, Vol. 128, nr 11, artikel-id e2022JG007185Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lakes contribute 9%-19% of global methane (CH4) emissions to the atmosphere. Dissolved molecular oxygen (DO) in lakes can inhibit the production of CH4 and promote CH4 oxidation. DO is therefore often considered an important regulator of CH4 emissions from lakes. Presence or absence of DO in the water above the sediments can affect CH4 production and emissions by (a) influencing if methane production can be fueled by the most reactive organic matter in the top sediment layer or rely on deeper and less degradable organic matter, and (b) enabling CH4 accumulation in deep waters and potentially large emissions upon water column turnover. However, the relative importance of these two DO effects on CH4 fluxes is still unclear. We assessed CH4 fluxes from two connected lake basins in northern boreal Sweden where one was experimentally oxygenated. Results showed no clear difference in summer CH4 emissions attributable to water column DO concentrations. Large amounts of CH4 accumulated in the anoxic hypolimnion of the reference basin but little of this may have been emitted because of incomplete mixing, and effective methane oxidation of stored CH4 reaching oxic water layers. Accordingly, <= 24% of the stored CH4 was likely emitted in the experimental lake. Overall, our results suggest that hypolimnetic DO and water column CH4 storage might have a smaller impact on CH4 emissions in boreal forest lakes than previous estimates, yet potential fluxes associated with water column turnover events remain a significant uncertainty in lake CH4 emission estimates.

  • 12.
    Pelissari, Maria Rogieri
    et al.
    Univ Sao Paulo, Brazil.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Bertassoli Junior, Dailson Jose
    Univ Sao Paulo, Brazil.
    Almeida, Nazare da Silva
    Univ Sao Paulo, Brazil.
    Sawakuchi, Andre Oliveira
    Univ Sao Paulo, Brazil.
    Water influence on CH4 and CO2 generation from tar sandstones: Insights from incubation experiments in the Piramboia Formation, Parana Basin2021Ingår i: Journal of South American Earth Sciences, ISSN 0895-9811, E-ISSN 1873-0647, Vol. 106, artikel-id 103097Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Processes controlling the biogenic production of CH4 and CO2 are relevant not only to environmental issues related to greenhouse gases emissions, but also in the energy scenario, since the biogenic generation of CH4 can be associated with the formation of natural gas reserves over time. This work aimed to evaluate the influence of water and calcium sulfate in the production of CH4 and CO2 from petroleum biodegradation in tar sandstones. Water saturation and sulfate concentration are taken to be important factors of influence in the oil biodegradation process. Long-term incubation experiments (up to 363 days) were carried out with samples of sandstone impregnated with high-viscosity hydrocarbons. The rocks used in this study were collected from outcrops of the Piramboia Formation, a known heavy-oil reservoir of the Parana Basin, Brazil. The net accumulation of both CH4 and CO2 was crescent during all the experiments performed, but with decreasing production rates through time. Average potential production rates obtained were 18 mL CH4/t.y (milliliter per ton of sandstone per year) and 54,000 mL CO2/t.y. The addition of water resulted in an average increase of 11% and 10% in the CH4 and CO2 cumulative production, respectively, in comparison with the dry incubation experiments. The water influence was stronger in the first 30 days of incubations when average production was around 70% higher in wet samples. Once the pH remained constant in the presence of calcium sulfate, the experiments indicate that calcium sulfate may function as buffer for pH, limiting acidification, which has a known negative influence on CH4 and CO2 production. Thus, the present work aims to alert for the potential of CO2 and CH4 production from tar sands in Brazil and for the importance of water as a positive influence on CH4 and CO2 generation from tar sandstones. This helps to evaluate the influence of environmental conditions on biogenic gas systems as well as on green-house gases emissions from geological sources, which are taken to be important sources of carbon to the atmosphere in a context of climate change.

    Ladda ner fulltext (pdf)
    fulltext
  • 13.
    Rudberg, David
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Duc, N. T.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Schenk, Jonathan
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sieczko, Anna Katarzyna
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Pajala, Gustav
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique Oliveira
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Department of Ecology and Environmental Sciences, Umeå Universitet, Umeå, Sweden.
    Verheijen, H. A.
    Department of Ecology and Environmental Sciences, Umeå Universitet, Umeå, Sweden.
    Melack, J. M.
    Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA University of California Santa Barbara, Earth Research Institute, Santa Barbara, CA, USA.
    MacIntyre, S.
    Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, USA University of California Santa Barbara, Earth Research Institute, Santa Barbara, CA, USA University of California Santa Barbara, Marine Science Institute, Santa Barbara, CA, USA.
    Karlsson, J.
    Department of Ecology and Environmental Sciences, Umeå Universitet, Umeå, Sweden.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Diel Variability of CO2 Emissions From Northern Lakes2021Ingår i: Journal of Geophysical Research - Biogeosciences, ISSN 2169-8953, E-ISSN 2169-8961, Vol. 126, nr 10, artikel-id e2021JG006246Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lakes are generally supersaturated in carbon dioxide (CO2) and emitters of CO2 to the atmosphere. However, estimates of CO2 flux (FCO2) from lakes are seldom based on direct flux measurements and usually do not account for nighttime emissions, yielding risk of biased assessments. Here, we present direct FCO2 measurements from automated floating chambers collected every 2-3 hr and spanning 115 24 hr periods in three boreal lakes during summer stratification and before and after autumn mixing in the most eutrophic lake of these. We observed 40%-67% higher mean FCO2 in daytime during periods of surface water CO2 supersaturation in all lakes. Day-night differences in wind speed were correlated with the day-night FCO2 differences in the two larger lakes, but in the smallest and most wind-sheltered lake peaks of FCO2 coincided with low-winds at night. During stratification in the eutrophic lake, CO2 was near equilibrium and diel variability of FCO2 insignificant, but after autumn mixing FCO2 was high with distinct diel variability making this lake a net CO2 source on an annual basis. We found that extrapolating daytime measurements to 24 hr periods overestimated FCO2 by up to 30%, whereas extrapolating measurements from the stratified period to annual rates in the eutrophic lake underestimated FCO2 by 86%. This shows the importance of accounting for diel and seasonal variability in lake CO2 emission estimates.

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  • 14.
    Rudberg, David
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Schenk, Jonathan
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Pajala, Gustav
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sieczko, Anna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologisk och miljövetenskaplig modellering. Linköpings universitet, Tekniska fakulteten.
    Sundgren, Ingrid
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Nguyen, Thanh Duc
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Karlsson, Jan
    Umea Univ, Sweden.
    Macintyre, Sally
    Univ Calif Santa Barbara, CA USA.
    Melack, John
    Univ Calif Santa Barbara, CA USA.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Contribution of gas concentration and transfer velocity to CO2 flux variability in northern lakes2024Ingår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The CO( 2)flux (FCO2) from lakes to the atmosphere is a large component of the global carbon cycle anddepends on the air-water CO2concentration gradient (Delta CO2) and the gas transfer velocity (k). Both Delta CO2 and k can vary on multiple timescales and understanding their contributions toFCO(2)is important for explaining var-iability influxes and developing optimal sampling designs. We measuredFCO2 and Delta CO(2 )and derivedkforone full ice-free period in 18 lakes usingfloating chambers and estimated the contributions of Delta CO2 and k to FCO2 variability. Generally, kcontributed more than Delta CO2to short-term (1-9d) FCO2 variability. With in creased temporal period, the contribution of k to FCO2 variability decreased, and in some lakes resulted in Delta CO2 contrib-uting more thank to FCO2 variability over the full ice-free period. Increased contribution of Delta CO2 to FCO2 vari-ability over time occurred across all lakes but was most apparent in large-volume southern-boreal lakes and indeeper (>2m) parts of lakes, whereaskwas linked to FCO(2 )variability in shallow waters. Accordingly, knowing the variability of bothk and Delta CO(2 )over time and space is needed for accurate modeling of F CO2 from these vari-ables. We conclude that priority in FCO(2 )assessments should be given to direct measurements of FCO2 at multiplesites when possible, or otherwise from spatially distributed measurements of Delta CO(2 )combined with k- models that incorporate spatial variability of lake thermal structure and meteorology.

  • 15.
    Rudberg, David
    et al.
    Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutionen för tema, Tema Miljöförändring.
    Thanh Duc, Nguyen
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Tekniska fakulteten.
    Schenk, Jonathan
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sieczko, Anna Katarzyna
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Teoretisk Biologi. Linköpings universitet, Tekniska fakulteten.
    Gustav, Pajala
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique Oliveira
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Verheijen, Hendricus
    Institutionen för ekologi, miljö och geovetenskap, Umeå Universitet, Umeå.
    Melak, John
    Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, US; Earth Research Institute, University of California, Santa Barbara, California, USA .
    MacIntyre, Sally
    Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, California, US; Earth Research Institute, University of California, Santa Barbara, California, USA; Marine Science Institute, University of California, Santa Barbara, California, USA .
    Karlsson, Jan
    Institutionen för ekologi, miljö och geovetenskap, Umeå Universitet, Umeå.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Source data for "Diel variability of CO2 emissions from Northern lakes and the effect of lake mixing"2020Dataset
    Ladda ner fulltext (xlsx)
    dataset
  • 16.
    Sawakuchi, Henrique
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Enrich Prast, Alex
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Ward, Nicholas D.
    Pacific Northwest Natl Lab, WA USA; Univ Washington, WA 98195 USA.
    Camargo, Plinio B.
    Univ Sao Paulo, Brazil.
    Richey, Jeffrey E.
    Univ Washington, WA 98195 USA.
    Low Diffusive Methane Emissions From the Main Channel of a Large Amazonian Run-of-the-River Reservoir Attributed to High Methane Oxidation2021Ingår i: Frontiers in Environmental Science, E-ISSN 2296-665X, Vol. 9, artikel-id 655455Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The global development of hydropower dams has rapidly expanded over the last several decades and has spread to historically non-impounded systems such as the Amazon Rivers main low land tributaries in Brazil. Despite the recognized significance of reservoirs to the global methane (CH4) emission, the processes controlling this emission remain poorly understood, especially in Tropical reservoirs. Here we evaluate CH4 dynamics in the main channel and downstream of the Santo Antonio hydroelectric reservoir, a large tropical run-of-the-river (ROR) reservoir in Amazonia. This study is intended to give a snapshot of the CH4 dynamics during the falling water season at the initial stage after the start of operations. Our results show substantial and higher CH4 production in reservoirs littoral sediment than in the naturally flooded areas downstream of the dam. Despite the large production in the reservoir or naturally flooded areas, high CH4 oxidation in the main channel keep the concentration and fluxes of CH4 in the main channel low. Similar CH4 concentrations in the reservoir and downstream close to the dam suggest negligible degassing at the dam, but stable isotopic evidence indicates the presence of a less oxidized pool of CH4 after the dam. ROR reservoirs are designed to disturb the natural river flow dynamics less than traditional reservoirs. If enough mixing and oxygenation remain throughout the reservoirs water column, naturally high CH4 oxidation rates can also remain and limit the diffusive CH4 emissions from the main channel. Nevertheless, it is important to highlight that our results focused on emissions in the deep and oxygenated main channel. High emissions, mainly through ebullition, may occur in the vast and shallow areas represented by bays and tributaries. However, detailed assessments are still required to understand the impacts of this reservoir on the annual emissions of CH4.

    Ladda ner fulltext (pdf)
    fulltext
  • 17.
    Sawakuchi, Henrique
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Umea Univ, Sweden.
    Martin, Gaetan
    Swedish Univ Agr Sci, Sweden.
    Peura, Sari
    Swedish Univ Agr Sci, Sweden.
    Bertilsson, Stefan
    Swedish Univ Agr Sci, Sweden.
    Karlsson, Jan
    Umea Univ, Sweden.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Phosphorus Regulation of Methane Oxidation in Water From Ice-Covered Lakes2021Ingår i: Journal of Geophysical Research - Biogeosciences, ISSN 2169-8953, E-ISSN 2169-8961, Vol. 126, nr 9, artikel-id e2020JG006190Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Winter methane (CH4) accumulation in seasonally ice-covered lakes can contribute to large episodic emissions to the atmosphere during spring ice melt. Biological methane oxidation can significantly mitigate such CH4 emissions, but despite favorable CH4 and O-2 concentrations, CH4 oxidation appears constrained in some lakes for unknown reasons. Here we experimentally test the hypothesis that phosphorus (P) availability is limiting CH4 oxidation, resulting in differences in ice-out emissions among lakes. We observed a positive relationship between potential CH4 oxidation and P concentration across 12 studied lakes and found an increase in CH4 oxidation in response to P amendment, without any parallel change in the methanotrophic community composition. Hence, while an increase in sedimentary CH4 production and ebullitive emissions may happen with eutrophication, our study indicates that the increase in P associated with eutrophication may also enhance CH4 oxidation. The increase in CH4 oxidation may hence play an important role in nutrient-rich ice-covered lakes where bubbles trapped under the ice may to a greater extent be oxidized, reducing the ice-out emissions of CH4. This may be an important factor regulating CH4 emissions from high latitude lakes.

    Ladda ner fulltext (pdf)
    fulltext
  • 18.
    Schenk, Jonathan
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique Oliveira
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sieczko, Anna Katarzyna
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Pajala, Gustav
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Rudberg, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Hagberg, Emelie
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Fors, Kjell
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Laudon, Hjalmar
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Karlsson, Jan
    Department of Ecology and Environmental Science, Climate Impacts Research Centre, Umeå University, Umeå, Sweden.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Data associated with the manuscript "Methane in Lakes: Variability in Stable Carbon Isotopic Composition and the Potential Importance of Groundwater Input"2021Dataset
    Ladda ner fulltext (csv)
    data set 1
    Ladda ner fulltext (csv)
    data set 2
    Ladda ner fulltext (csv)
    data set 3
  • 19.
    Schenk, Jonathan
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique Oliveira
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sieczko, Anna Katarzyna
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Pajala, Gustav
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Rudberg, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Hagberg, Emelie
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Fors, Kjell
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Laudon, Hjalmar
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Karlsson, Jan
    Climate Impacts Research Centre, Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Methane in Lakes: Variability in Stable Carbon Isotopic Composition and the Potential Importance of Groundwater Input2021Ingår i: Frontiers in Earth Science, E-ISSN 2296-6463, Vol. 9, artikel-id 722215Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Methane (CH4) is an important component of the carbon (C) cycling in lakes. CH4 production enables carbon in sediments to be either reintroduced to the food web via CH4 oxidation or emitted as a greenhouse gas making lakes one of the largest natural sources of atmospheric CH4. Large stable carbon isotopic fractionation during CH4 oxidation makes changes in 13C:12C ratio (δ13C) a powerful and widely used tool to determine the extent to which lake CH4 is oxidized, rather than emitted. This relies on correct δ13C values of original CH4 sources, the variability of which has rarely been investigated systematically in lakes. In this study, we measured δ13C in CH4 bubbles in littoral sediments and in CH4 dissolved in the anoxic hypolimnion of six boreal lakes with different characteristics. The results indicate that δ13C of CH4 sources is consistently higher (less 13C depletion) in littoral sediments than in deep waters across boreal and subarctic lakes. Variability in organic matter substrates across depths is a potential explanation. In one of the studied lakes available data from nearby soils showed correspondence between δ13C-CH4 in groundwater and deep lake water, and input from the catchment of CH4 via groundwater exceeded atmospheric CH4 emissions tenfold over a period of 1 month. It indicates that lateral hydrological transport of CH4 can explain the observed δ13C-CH4 patterns and be important for lake CH4 cycling. Our results have important consequences for modelling and process assessments relative to lake CH4 using δ13C, including for CH4 oxidation, which is a key regulator of lake CH4 emissions.

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  • 20.
    Schenk, Jonathan
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sieczko, Anna Katarzyna
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Rudberg, David
    Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutionen för tema, Tema Miljöförändring.
    Pajala, Gustav
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique Oliveira
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Gålfalk, Magnus
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sundgren, Ingrid
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Thanh Duc, Nguyen
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Tekniska fakulteten.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Evaluating Empirical Models of Lake Methane Emission and Surface Water Concentration across Hemiboreal to Subarctic Regions2022Dataset
    Ladda ner fulltext (xlsx)
    Table 1 in the corresponding manuscript
    Ladda ner fulltext (xlsx)
    Table 2 in the corresponding manuscript
  • 21.
    Sieczko, Anna Katarzyna
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Dang, Nguyen Thong
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Schenk, Jonathan
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Pajala, Gustav
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Rudberg, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten. Umea Univ, Sweden.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Diel variability of methane emissions from lakes2020Ingår i: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 117, nr 35, s. 21488-21494Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lakes are considered the second largest natural source of atmospheric methane (CH4). However, current estimates are still uncertain and do not account for diel variability of CH4 emissions. In this study, we performed high-resolution measurements of CH4 flux from several lakes, using an automated and sensor-based flux measurement approach (in total 4,580 measurements), and demonstrated a clear and consistent diel lake CH4 flux pattern during stratification and mixing periods. The maximum of CH4 flux were always noted between 10:00 and 16:00, whereas lower CH4 fluxes typically occurred during the nighttime (00:00-04:00). Regardless of the lake, CH4 emissions were on an average 2.4 higher during the day compared to the nighttime. Fluxes were higher during daytime on nearly 80% of the days. Accordingly, estimates and extrapolations based on daytime measurements only most likely result in overestimated fluxes, and consideration of diel variability is critical to properly assess the total lake CH4 flux, representing a key component of the global CH4 budget. Hence, based on a combination of our data and additional literature information considering diel variability across latitudes, we discuss ways to derive a diel variability correction factor for previous measurements made during daytime only.

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  • 22.
    Sieczko, Anna Katarzyna
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Ekologisk och miljövetenskaplig modellering. Linköpings universitet, Tekniska fakulteten.
    Schenk, Jonathan
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Rudberg, David
    Linköpings universitet, Filosofiska fakulteten. Linköpings universitet, Institutionen för tema, Tema Miljöförändring.
    Nguyen, Thanh Duc
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Tekniska fakulteten.
    Pajala, Gustav
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Data set associated with the manuscript submitted to Science of the Total Environment by Sieczko et.al 20232023Dataset
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  • 23.
    Sieczko, Anna
    et al.
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Schenk, Jonathan
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Rudberg, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Nguyen, Thanh Duc
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Pajala, Gustav
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Bastviken, David
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Minor impacts of rain on methane flux from hemiboreal, boreal, and subarctic lakes2023Ingår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 895, artikel-id 164849Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Methane (CH4) emissions (FCH4) from northern freshwater lakes are not only significant but also highly variable in time and one driver variable suggested to be important is precipitation. Rain can have various, potentially large effects on FCH4 across multiple time frames, and verifying the impact of rain on lake FCH4 is key to understand both contemporary flux regulation, and to predict future FCH4 related to possible changes in frequency and intensity of rainfall from climate change. The main objective of this study was to assess the short-term impact of typically occurring rain events with different intensity on FCH4 from various lake types located in hemiboreal, boreal, and subarctic Sweden. In spite of high time resolution automated flux measurements across different depth zones and covering numerous commonly types of rain events in northern areas, in general, no strong impact on FCH4 during and within 24 h after the rainfall could be observed. Only in deeper lake areas and during longer rain events FCH4 was weakly related to rain (R2 = 0.29, p < 0.05), where a minor FCH4 decrease during the rain was identified, suggesting that direct rainwater input, during greater rainfall, may decrease FCH4 by dilution of surface water CH4. Overall, this study indicates that typical rain events in the studied regions have minor direct short-term effects on FCH4 from northern lakes and do not enhance FCH4 from shallow and deeper parts of lakes during and up to 24-h after the rainfall. Instead, other factors such as wind speed, water temperature and pressure changes were more strongly correlated with lake FCH4.

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  • 24.
    Valerio, Aline M.
    et al.
    Natl Inst Space Res, Brazil.
    Kampel, Milton
    Natl Inst Space Res, Brazil.
    Ward, Nicholas D.
    Pacif Northwest Natl Lab, WA USA; Univ Washington, WA 98195 USA.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Cunha, Alan C.
    Univ Fed Amapa, Brazil.
    Richey, Jeffrey E.
    Univ Washington, WA 98195 USA.
    CO2 partial pressure and fluxes in the Amazon River plume using in situ and remote sensing data2021Ingår i: Continental Shelf Research, ISSN 0278-4343, E-ISSN 1873-6955, Vol. 215, artikel-id 104348Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Estimations of the global carbon budget include a quantitative understanding of the evolving processes that occur along river-to-ocean gradients. However, high spatiotemporal resolution observations of these processes are limited. Here we present in situ measurements of the partial pressure of CO2 (pCO(2)) made through the Amazon River plume (ARP) during different discharge seasons, from 2010 to 2012. We evaluated the spatiotemporal distribution of pCO(2) using Soil Moisture and Ocean Salinity (SMOS) satellite observations for each hydrologic period in the ARP. Regression models were used to estimate pCO(2) at the ARP for the period of 2010-2014. From these distributions we calculated sea-air gas exchange of CO2 between the plume waters and the atmosphere (F-co2(sea)). Intra-annual variability of Fseaco(2) was related to discharge at the river mouth and ocean currents as well as trade winds in the plume. Climatic events during the study period had a significant impact on the Fsea co(2). Including the plume area closer to the river mouth makes the ARP a net source of CO2 with an annual net sea-air flux of 8.6 +/- 7.1 Tg C y(-1) from 2011 to 2014.

  • 25.
    Ward, Nicholas D.
    et al.
    Pacific Northwest Natl Lab, WA 98382 USA; Univ Washington, WA 98195 USA; Univ Florida, FL 32611 USA.
    Bianchi, Thomas S.
    Univ Florida, FL 32611 USA.
    Martin, Jonathan B.
    Univ Florida, FL 32611 USA.
    Quintero, Carlos J.
    Univ Florida, FL USA.
    Sawakuchi, Henrique
    Linköpings universitet, Institutionen för tema, Tema Miljöförändring. Linköpings universitet, Filosofiska fakulteten.
    Cohen, Matthew J.
    Univ Florida, FL 32611 USA.
    Pathways for Methane Emissions and Oxidation that Influence the Net Carbon Balance of a Subtropical Cypress Swamp2020Ingår i: Frontiers in Earth Science, E-ISSN 2296-6463, Vol. 8, artikel-id 573357Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We evaluated the major pathways for methane emissions from wetlands to the atmosphere at four wetland sites in the Big Cypress National Preserve in southwest Florida. Methane oxidation was estimated based on the delta C-13-CH4 of surface water, porewater, and bubbles to evaluate mechanisms that limit surface water emissions. Spatially-scaled methane fluxes were then compared to organic carbon burial rates. The pathway with the lowest methane flux rate was diffusion from surface waters (3.50 +/- 0.22 mmol m(-2) d(-1)). Microbial activity in the surface water environment and/or shallow oxic sediment layer oxidized 26 +/- 3% of the methane delivered from anerobic sediments to the surface waters. The highest rates of diffusion were observed at the site with the lowest extent of oxidation. Ebullition flux rates were 2.2 times greater than diffusion and more variable (7.79 +/- 1.37 mmol m(-2) d(-1)). Methane fluxes from non-inundated soils were 1.6 times greater (18.4 +/- 5.14 mmol m(-2) d(-1)) than combined surface water fluxes. Methane flux rates from cypress knees (emergent cypress tree root structures) were 3.7 and 2.3 times higher (42.0 +/- 6.33 mmol m(-2) d(-1)) than from surface water and soils, respectively. Cypress knee flux rates were highest at the wetland site with the highest porewater methane partial pressure, suggesting that the emergent root structures allow methane produced in anaerobic sediment layers to bypass oxidation in aerobic surface waters or shallow sediments. Scaled across the four wetlands, emissions from surface water diffusion, ebullition, non-inundated soils, and knees contributed to 14 +/- 2%, 25 +/- 6%, 34 +/- 10%, and 26 +/- 5% of total methane emissions, respectively. When considering only the three wetlands with cypress knees present, knee emissions contributed to 39 +/- 5% of the total scaled methane emissions. Finally, the molar ratio of CH4 emissions to OC burial ranged from 0.03 to 0.14 in the wetland centers indicating that all four wetland sites are net sources of atmospheric warming potential on 20-100 yr timescales, but net sinks over longer time scales (500 yr) with the exception of one wetland site that was a net source even over 500 yr time scales.

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