Extensive release of methane from Arctic seabed west of Svalbard during summer 2014 does not influence the atmosphere

Author(s): C. Lund Myhre, B. Ferré, S. M. Platt, A. Silyakova, O. Hermansen, G. Allen, I. Pisso, N. Schmidbauer, A. Stohl, J. Pitt, P. Jansson, J. Greinert, C. Percival, A. M. Fjaeraa, S. J. O'Shea, M. Gallagher, M. Le Breton, K. N. Bower, S. J.B. Bauguitte, S. Dalsøren, S. Vadakkepuliyambatta, R. E. Fisher, E. G. Nisbet, D. Lowry, G. Myhre, J. A. Pyle, M. Cain, J. Mienert
Abstract: We find that summer methane (CH₄) release from seabed sediments west of Svalbard substantially increases CH₄ concentrations in the ocean but has limited influence on the atmospheric CH₄ levels. Our conclusion stems from complementary measurements at the seafloor, in the ocean, and in the atmosphere from land-based, ship and aircraft platforms during a summer campaign in 2014. We detected high concentrations of dissolved CH₄ in the ocean above the seafloor with a sharp decrease above the pycnocline. Model approaches taking potential CH₄ emissions from both dissolved and bubble-released CH₄ from a larger region into account reveal a maximum flux compatible with the observed atmospheric CH₄ mixing ratios of 2.4-3.8 nmol m^-2 s^-1. This is too low to have an impact on the atmospheric summer CH₄ budget in the year 2014. Long-term ocean observatories may shed light on the complex variations of Arctic CH₄ cycles throughout the year.
Organisation(s): Department of Meteorology and Geophysics
External organisation(s): Norwegian Institute for Air Research, University of Tromsø - The Arctic University of Norway, National Centre for Atmospheric Sciences (NCAS), University of Manchester, GEOMAR Helmholtz-Zentrum für Ozeanforschung, Christian-Albrechts-Universität zu Kiel, Facility for Airborne Atmospheric Measurments (FAAM), Natural Environment Research Council, Centre for International Climate and Environmental Research, University of London, University of Cambridge
Journal: Geophysical Research Letters
Volume: 43
Pages: 4624-4631
No. of pages: 8
ISSN: 0094-8276
DOI: https://doi.org/10.1002/2016GL068999
Publication date: 05-2016
Peer reviewed: Yes
Austrian Fields of Science 2012: 105206 Meteorology
Keywords
ASJC Scopus subject areas: Geophysics, Earth and Planetary Sciences(all)
Sustainable Development Goals: SDG 13 - Climate Action
Portal url: https://ucrisportal.univie.ac.at/en/publications/extensive-release-of-methane-from-arctic-seabed-west-of-svalbard-during-summer-2014-does-not-influence-the-atmosphere(94698dd3-2546-4ef6-ac4f-681609add1a5).html

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