• Autonomous methane seep site monitoring offshore western Svalbard: hourly to seasonal variability and associated oceanographic parameters 

      Dølven, Knut Ola; Ferré, Benedicte; Silyakova, Anna; Jansson, Pär; Linke, Peter; Moser, Manuel (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-18)
      Improved quantification techniques of natural sources are needed to explain variations in atmospheric methane. In polar regions, high uncertainties in current estimates of methane release from the seabed remain. We present unique 10- and 3-month time series of bottom water measurements of physical and chemical parameters from two autonomous ocean observatories deployed at separate intense seabed ...
    • The law of the sea and current practices of marine scientific research in the Arctic 

      Woker, Hilde; Schartmüller, Bernhard; Dølven, Knut Ola; Blix, Katalin (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-02-07)
      The rapid changes in both climate and human activity occurring in the Arctic Ocean demands improved knowledge about this region. Combined with eased accessibility due to reduced sea ice cover and new technologies, this has led to increased research activity in the region. These circumstances put pressure on the applicable legal framework, i.e. the United Nations Convention on the Law of the Sea. ...
    • Measuring Methane in the Arctic Ocean - From legal framework to time series analysis via technology innovation 

      Dølven, Knut Ola (Doctoral thesis; Doktorgradsavhandling, 2022-03-24)
      <p>Understanding how the earth system interacts with ongoing climate change is important to find a realistic route towards a sustainable future. The impact of Arctic seabed methane seepage on contemporary and future climate is still poorly constrained, described, and quantified. An important limiting factor in our understanding of seabed seepage in the Arctic is a lack of in situ measurements; ...
    • A new numerical model for understanding free and dissolved gasprogression toward the atmosphere in aquatic methane seepage systems 

      Jansson, Pär; Ferré, Benedicte; Silyakova, Anna; Dølven, Knut Ola; Omstedt, Anders (Journal article; Tidsskriftartikkel; Peer reviewed, 2019-01-16)
      We present a marine two‐phase gas model in one dimension (M2PG1) resolving interaction between the free and dissolved gas phases and the gas propagation toward the atmosphere in aquatic environments. The motivation for the model development was to improve the understanding of benthic methane seepage impact on aquatic environments and its effect on atmospheric greenhouse gas composition. Rising, ...
    • Response time correction of slow-response sensor data by deconvolution of the growth-law equation 

      Dølven, Knut Ola; Vierinen, Juha; Grilli, Roberto; Triest, Jack; Ferré, Benedicte (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-08-11)
      Accurate high-resolution measurements are essential to improve our understanding of environmental processes. Several chemical sensors relying on membrane separation extraction techniques have slow response times due to a dependence on equilibrium partitioning across the membrane separating the measured medium (i.e., a measuring chamber) and the medium of interest (i.e., a solvent). We present a new ...
    • Variability of Marine Methane Bubble Emissions on the Clayoquot Slope, Offshore Vancouver Island, Between 2017 and 2021 

      Marcon, Yann; Römer, Miriam; Scherwath, Martin; Riedel, Michael; Dølven, Knut Ola; Heesemann, Martin (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-03-17)
      Seabed methane gas emissions occur worldwide at cold seeps located along most continental margins. Fluxes of methane gas released from the seabed in the form of bubbles can be extremely variable even over short time intervals. Some factors controlling the variability are still poorly understood. Here, we report on the results of continuous long-term sonar monitoring of bubble emissions at a depth ...