• All-sky camera system providing high temporal resolution annual time series of irradiance in the arctic 

      Johnsen, Geir; Zolich, Artur; Grant, Stephen; Bjorgum, Rune; Cohen, Jonathan H.; Mckee, David; Kopec, Tomasz Piotr; Vogedes, Daniel Ludwig; Berge, Jorgen (Journal article; Peer reviewed, 2021)
      The ArcLight observatory provides hourly continuous time series of light regime data (intensity, spectral composition, and photoperiod) from the Arctic, Svalbard at 79° N. Until now, no complete annual time series of ...
    • Artificial light during the polar night disrupts Arctic fish and zooplankton behavior down to 200 m depth 

      Berge, Jørgen; Geoffroy, Maxime; Daase, Malin; Cottier, Finlo Robert; Priou, Pierre; Cohen, Jonathan H.; Johnsen, Geir; McKee, David; Kostakis, I; Renaud, Paul E.; Vogedes, Daniel Ludwig; Anderson, Philip J.; Last, Kim; Gauthier, Stephane (Peer reviewed; Journal article, 2020)
      For organisms that remain active in one of the last undisturbed and pristine dark environments on the planet—the Arctic Polar Night—the moon, stars and aurora borealis may provide important cues to guide distribution and ...
    • Bioluminescence as an ecological factor during high Arctic polar night 

      Cronin, Heather; Cohen, Jonathan H.; Berge, Jørgen; Johnsen, Geir; Moline, Mark A. (Journal article; Peer reviewed, 2016)
      Bioluminescence commonly influences pelagic trophic interactions at mesopelagic depths. Here we characterize a vertical gradient in structure of a generally low species diversity bioluminescent community at shallower ...
    • Is ambient light during the high Arctic polar night sufficient to act as a visual cue for zooplankton? 

      Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Sørensen, Asgeir Johan; Last, Kim; Falk-Petersen, Stig; Renaud, Paul; Leu, Eva; Grenvald, Julie Cornelius; Cottier, Finlo; Cronin, Heather; Menze, Sebastian; Norgren, Petter; Varpe, Øystein; Daase, Malin; Darnis, Gérald; Johnsen, Geir (Journal article, 2015)
      The light regime is an ecologically important factor in pelagic habitats, influencing a range of biological processes. However, the availability and importance of light to these processes in high Arctic zooplankton communities ...
    • Light in the Polar Night 

      Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Johnsen, Geir; Zolich, Artur Piotr (Chapter, 2020)
      How much light isa vailable for biological processes during Polar Night? This question appears simple enough. But the reality is that conventional light sen- sors for measuring visible light (~350 to ~700 nm) have not been ...
    • A marine zooplankton community vertically structured by light across diel to interannual timescales 

      Hobbs, Laura; Banas, Neil S.; Cohen, Jonathan H.; Cottier, Finlo Robert; Berge, Jørgen; Varpe, Øystein (Journal article; Peer reviewed, 2021)
      The predation risk of many aquatic taxa is dominated by visually searching predators, commonly a function of ambient light. Several studies propose that changes in visual predation will become a major climate-change impact ...
    • Operative Habitat Mapping and Monitoring in the Polar Night 

      Johnsen, Geir; Mogstad, Aksel Alstad; Berge, Jørgen; Cohen, Jonathan H. (Chapter, 2020)
      The Polar Night has long been regarded as a period of no biological activity. As a logical consequence, environmental management has mainly been neglected in this period. We will use the Northguider accident in December ...
    • Pelagic organisms avoid white, blue, and red artificial light from scientific instruments 

      Geoffroy, Maxime; Langbehn, Tom; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Le Bris, Arnault; Fisher, Jonathan A. D.; Daase, Malin; Mckee, David; Cohen, Jonathan H.; Berge, Jørgen (Journal article; Peer reviewed, 2021)
      In situ observations of pelagic fish and zooplankton with optical instruments usually rely on external light sources. However, artificial light may attract or repulse marine organisms, which results in biased measurements. ...
    • Photophysiological cycles in Arctic krill are entrained by weak midday twilight during the Polar Night 

      Cohen, Jonathan H.; Last, Kim; Charpentier, Corie L.; Cottier, Finlo; Daase, Malin; Hobbs, Laura; Johnsen, Geir; Berge, Jørgen (Peer reviewed; Journal article, 2021)
      Light plays a fundamental role in the ecology of organisms in nearly all habitats on Earth and is central for processes such as vision and the entrainment of the circadian clock. The poles represent extreme light regimes ...
    • Use of an Autonomous Surface Vehicle reveals small-scale diel vertical migrations of zooplankton and susceptibility to light pollution under low solar irradiance 

      Ludvigsen, Martin; Berge, Jørgen; Geoffroy, Maxime; Cohen, Jonathan H.; De La Torre, Pedro R.; Nornes, Stein Melvær; Singh, Hanumant; Sørensen, Asgeir Johan; Daase, Malin; Johnsen, Geir (Journal article; Peer reviewed, 2018)
      Light is a major cue for nearly all life on Earth. However, most of our knowledge concerning the importance of light is based on organisms’ response to light during daytime, including the dusk and dawn phase. When it is ...