Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 12, issue 23
Biogeosciences, 12, 7013–7024, 2015
https://doi.org/10.5194/bg-12-7013-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
Biogeosciences, 12, 7013–7024, 2015
https://doi.org/10.5194/bg-12-7013-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Technical note 07 Dec 2015

Technical note | 07 Dec 2015

Technical note: drifting versus anchored flux chambers for measuring greenhouse gas emissions from running waters

A. Lorke1, P. Bodmer2,3, C. Noss1, Z. Alshboul1, M. Koschorreck4, C. Somlai-Haase1, D. Bastviken5, S. Flury2, D. F. McGinnis2,6, A. Maeck7, D. Müller8,9, and K. Premke2,10 A. Lorke et al.
  • 1Institute for Environmental Sciences, University of Koblenz-Landau, Fortstr. 7, 76829 Landau, Germany
  • 2Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Chemical Analytics and Biogeochemistry, Müggelseedamm 310, 12587 Berlin, Germany
  • 3Institute of Biology, Freie Universität Berlin, 14195 Berlin, Germany
  • 4Helmholtz Centre for Environmental Research – UFZ, Department Lake Research, Brückstr. 3a, 39114 Magdeburg, Germany
  • 5Linköping University, Department of Thematic Studies – Environmental Change, 58183 Linköping, Sweden
  • 6Institute F.-A. Forel, Section of Earth and Environmental Sciences, University of Geneva, Geneva, Switzerland
  • 7Senect GmbH & Co. KG, An 44 – No. 11, 76829 Landau, Germany
  • 8Institute of Environmental Physics (IUP), Otto-Hahn-Allee 1, 28359 Bremen, Germany
  • 9Center for Tropical Marine Ecology (ZMT), Fahrenheitsstr. 8, 28359 Bremen, Germany
  • 10Leibniz Centre for Agricultural Landscape Research, Institute for Landscape Biogeochemistry, Eberswalder Straße 84, 15374 Müncheberg, Germany

Abstract. Stream networks have recently been discovered to be major but poorly constrained natural greenhouse gas (GHG) sources. A fundamental problem is that several measurement approaches have been used without cross-comparisons. Flux chambers represent a potentially powerful methodological approach if robust and reliable ways to use chambers on running water can be defined. Here we compare the use of anchored and freely drifting chambers on various streams with different flow velocities. The study clearly shows that (1) anchored chambers enhance turbulence under the chambers and thus elevate fluxes, (2) drifting chambers have a very small impact on the water turbulence under the chamber and thus generate more reliable fluxes, (3) the bias of the anchored chambers greatly depends on chamber design and sampling conditions, and (4) there is a promising method to reduce the bias from anchored chambers by using a flexible plastic foil collar to seal the chambers to the water surface, rather than having rigid chamber walls penetrating into the water. Altogether, these results provide novel guidance on how to apply flux chambers in running water, which will have important consequences for measurements to constrain the global GHG balances.

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Flux chambers represent a potentially powerful methodological approach for measuring greenhouse gas emissions from running waters. Here we compare the use of anchored and freely drifting chambers on various streams and provide novel guidance on how to apply flux chambers in these systems. The study clearly shows that drifting chambers have a very small impact on the water turbulence under the chamber, while anchored chambers enhance turbulence under the chambers and thus elevate fluxes.
Flux chambers represent a potentially powerful methodological approach for measuring greenhouse...
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