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English

Geir Johnsen

Geir Johnsen

Professor
Institutt for biologi

geir.johnsen@ntnu.no
73591581 91897027 Biologisk stasjon, 01.nov, Trondheim, Bynesveien 46
Om Publikasjoner Undervisning Formidling

Om

CV

Geir Johnsen is a professor in marine biology at the Department of Biology (NTNU at Trondhjem biological station, TBS), Prof II at University Centre on Svalbard (UNIS), and is one of the founding partners in a NTNU spin-off company Ecotone using new optical techniques for mapping and monitoring the marine environment. He is a key scientist in the Centre of excellence (CeO) "Autonomous Marine Operations and Systems (AMOS) using enabling technology for marine ecological studies.

He has been at 1 years research stays at University of California at Santa Barbara (1992-93) , Curtin University, Perth, Australia (2010-11) and University of Hawaii at Manoa, Honolulu (2018-19). 

Adviser for 48 MSc and 17 PhD students graduated. Currently he advises 7 PhD candidates and 2 post docs. He have published >140 papers in international scientific journals and been a co-editor for the books "Ecosystem Barents Sea" (Tapir Academic Press, 2009), Phytoplankton pigments: Updates on Characterization, Chemotaxonomy and Applications in Oceanography (Cambridge University Press, 2011) and “Life and Light in the Dead of Night” (Springer-Nature, published end of March 2020).

Research areas

  • Marine ecology and biodiversity in temperate, tropical and arctic regions
  • Bio-optics
  • Photosynthesis and eco-physiology in phytoplankton, ice algae and macroalgae
  • Pigment chemotaxonomy, light harvesting and photo-protective function
  • Underwater robotics and sensor development for in situ identification of organisms
  • Mapping and monitoring of bio-geo-chemical objects of interest in the marine environment
  • Polar night marine ecology
  • Photo-biology - Light as a cue of light


 

Publikasjoner

  • Kronologisk
  • Etter kategori
  • Se alle publikasjoner i Cristin

2023

  • Williamson, David Roddan; Moreira Fragoso, Glaucia; Majaneva, Sanna Kristiina; Dallolio, Alberto; Halvorsen, Daniel Ørnes; Hasler, Oliver Kevin. (2023) Monitoring Algal Blooms with Complementary Sensors on Multiple Spatial and Temporal Scales. Oceanography
    Vitenskapelig artikkel
  • Bakken, Sivert; Henriksen, Marie Bøe; Birkeland, Roger; Langer, Dennis David; Oudijk, Adriënne Esmeralda; Berg, Simen. (2023) HYPSO-1 CubeSat: First Images and In-Orbit Characterization. Remote Sensing
    Vitenskapelig artikkel
  • Summers, Natalie Maria; Moreira Fragoso, Glaucia; Johnsen, Geir. (2023) Photophysiologically active green, red, and brown macroalgae living in the Arctic Polar Night. Scientific Reports
    Vitenskapelig artikkel
  • Grant, Stephen Denis; Johnsen, Geir; McKee, David; Zolich, Artur Piotr; Cohen, Jonathan H.. (2023) Spectral and RGB analysis of the light climate and its ecological impacts using an all-sky camera system in the Arctic. Applied Optics
    Vitenskapelig artikkel
  • Gerland, Sebastian; Ingvaldsen, Randi Brunvær; Reigstad, Marit; Sundfjord, Arild; Bogstad, Bjarte; Chierici, Melissa. (2023) Still Arctic? — The changing Barents Sea. Elementa: Science of the Anthropocene
    Vitenskapelig oversiktsartikkel/review
  • Schartmuller, Bernhard; Anderson, Philip; Mckee, David; Connan-McGinty, Stacey; Kopec, Tomasz Piotr; Daase, Malin Hildegard Elisabeth. (2023) Development and calibration of a high dynamic range and autonomous ocean-light instrument to measure sub-surface profiles in ice-covered waters. Applied Optics
    Vitenskapelig artikkel

2022

  • Nøland, Annecken; Johnsen, Geir; Aberle-Malzahn, Nicole. (2022) Autonomous Underwater Vehicle (AUV) based study of zooplankton communities, using a silhouette camera and artificial intelligence. NTNU
    Mastergradsoppgave
  • Johnsen, Geir; Aberle-Malzahn, Nicole; Fragoso, Glaucia; Thu, Maren. (2022) Phytoplankton Spring Bloom Mapping in Coastal Areas Using Autonomous Underwater Vehicle (AUV) and Optical Approaches. NTNU
    Mastergradsoppgave
  • Zolich, Artur Piotr; Faltynkova, Andrea; Johnsen, Geir; Johansen, Tor Arne. (2022) Portable Catamaran Drone - an uncrewed sampling vehicle for micro-plastics and aquaculture research.
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Summers, Natalie; Johnsen, Geir; Mogstad, Aksel Alstad; Løvås, Håvard; Fragoso, Glaucia Moreira; Berge, Jørgen. (2022) Underwater Hyperspectral Imaging of Arctic Macroalgal Habitats during the Polar Night Using a Novel Mini-ROV-UHI Portable System. Remote Sensing
    Vitenskapelig artikkel
  • Fragoso, Glaucia Moreira; Davies, Emlyn John; Fossum, Trygve Olav; Ullgren, Jenny; Majaneva, Sanna; Aberle-Malzahn, Nicole. (2022) Contrasting phytoplankton-zooplankton distributions observed through autonomous platforms, in-situ optical sensors and discrete sampling. PLOS ONE
    Vitenskapelig artikkel
  • Mogstad, Aksel Alstad; Løvås, Håvard; Sture, Øystein; Johnsen, Geir; Ludvigsen, Martin. (2022) Remote Sensing of the Tautra Ridge: An Overview of the World’s Shallowest Cold-Water Coral Reefs. Frontiers in Marine Science
    Vitenskapelig artikkel
  • Nevstad, Malin Bø; Johnsen, Geir; Bakken, Torkild; Larsen, Martin Kvisvik; Mogstad, Aksel Alstad. (2022) Use of different imaging systems for ROV-based mapping of complex benthic habitats. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Marnor, Camilla Mult; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Mapping distribution patterns of brittle stars using ROV-based imaging. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Bjerkvoll, Mikkel; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Aerial and underwater hyperspectral imagery for shallow benthic nature type mapping. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Søreng, Marte Opsahl; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad; Gryte, Kristoffer. (2022) Mapping of Zostera Habitat in the Sublittoral Zone using Underwater Hyperspectral Imaging and Unmanned Surface Vehicle. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Connan-McGinty, Stacey; Banas, Neil S.; Berge, Jørgen; Cottier, Finlo Robert; Grant, Stephen; Johnsen, Geir. (2022) Midnight Sun to Polar Night: A Model of Seasonal Light in the Barents Sea. Journal of Advances in Modeling Earth Systems
    Vitenskapelig artikkel
  • Oudijk, Esmée; Hasler, Oliver Kevin; Øveraas, Henning; Marty, Sabine; Williamson, David Roddan; Svendsen, Torbjørn Karl. (2022) Campaign For Hyperspectral Data Validation In North Atlantic Coastal Waters. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
    Vitenskapelig artikkel
  • Dona, Angela; Evertsen, Jussi; Johnsen, Geir. (2022) The role of parapodia and lack of photoacclimation in kleptoplasts of the sacoglossan sea slug Plakobranchus ocellatus. Coral reefs
    Vitenskapelig artikkel

2021

  • Cohen, Jonathan H.; Last, Kim; Charpentier, Corie L.; Cottier, Finlo; Daase, Malin; Hobbs, Laura. (2021) Photophysiological cycles in Arctic krill are entrained by weak midday twilight during the Polar Night. PLoS Biology
    Vitenskapelig artikkel
  • Cardwell, CR; Berge, Jørgen; Johnsen, Geir. (2021) Arctic voyage shines light on some cold, hard truths. The Herald, UK
    Populærvitenskapelig artikkel
  • Bazilchuk, Nancy Reney; Berge, Jørgen; Johnsen, Geir. (2021) Lysforurensning I Arktis kan ha ødelagt forskningsresultater. Gemini.no
    Populærvitenskapelig artikkel
  • Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2019) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer.
    Annet produkt
  • Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2018) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer. .
    Annet produkt
  • Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2019) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
    Annet produkt
  • Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2020) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
    Annet produkt
  • Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2017).
    Annet produkt
  • Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2018) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
    Annet produkt
  • Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2020) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
    Annet produkt
  • Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2019) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
    Annet produkt
  • Ringvold, Halldis; Taite, Morag; Allcock, A. Louise; Vecchione, Michael; Péan, Michel; Sandulli, Roberto. (2021) In situ recordings of large gelatinous spheres from NE Atlantic, and the first genetic confirmation of egg mass of Illex coindetii (Vérany, 1839) (Cephalopoda, Mollusca). Scientific Reports
    Vitenskapelig artikkel
  • Bakken, Sivert; Johnsen, Geir; Johansen, Tor Arne. (2021) Analysis and Model Development of Direct Hyperspectral Chlorophyll-A Estimation for Remote Sensing Satellites. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
    Vitenskapelig artikkel
  • Horni, K; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin. (2021) Internasjonalt forskningsmiljø dykker i Mjøsa etter at Oppland Arbeiderblad skrev om forurensning. Oppland arbeiderblad
    Populærvitenskapelig artikkel
  • Bazilchuk, Nancy Reney; Stahl, Annette; Johnsen, Geir; Saad, Aya; Thu, Maren; Nøland, Annecken. (2021) Sporhunden som lukter mikroalger. . Gemini.no
    Populærvitenskapelig artikkel
  • Ringvold, Halldis; Johnsen, Geir; Andersen, Tom. (2021) Studies on Echinodermata from the NE Atlantic Ocean - Spatial distribution and abundance of Asteroidea, including taxonomic and molecular studies on Crossaster and Henricia genera - Value-chain results, including test fishery, biology, market and nutritional analysis on Parastichopus tremulus (Holothuroidea) from the Norwegian coast. Doktoravhandlinger ved NTNU (2021-254)
    Doktorgradsavhandling
  • Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2021) Underwater hyperspectral imaging as a tool for benthic habitat mapping. Doktoravhandlinger ved NTNU (2021/271)
    Doktorgradsavhandling
  • Snyder, Mike; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2021) “Into the dark” documentary by Mike Snyder following Jørgen Berge (UiT), Geir Johnsen (NTNU) and David McKee (Uni Strathclyde) during Polar Night marine ecology work. .
    Film
  • Johnsen, Geir; Zolich, Artur; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan H.; Mckee, David. (2021) All-sky camera system providing high temporal resolution annual time series of irradiance in the arctic. Applied Optics
    Vitenskapelig artikkel
  • Geoffroy, Maxime; Langbehn, Tom Jasper; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Le Bris, Arnault. (2021) Pelagic organisms avoid white, blue, and red artificial light from scientific instruments. Scientific Reports
    Vitenskapelig artikkel
  • Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2019).
    Annet produkt
  • Løvås, Håvard; Mogstad, Aksel Alstad; Sørensen, Asgeir Johan; Johnsen, Geir. (2021) A Methodology for Consistent Georegistration in Underwater Hyperspectral Imaging. IEEE Journal of Oceanic Engineering
    Vitenskapelig artikkel
  • Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2018).
    Annet produkt
  • Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Pictures from an all-sky camera with hourly resolution from the light observatory at Ny-Ålesund, Svalbard, Norway (complete year 2020).
    Annet produkt
  • Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2017) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) .
    Annet produkt
  • Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Photosynthetic active radiation (PAR) time series measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
    Annet produkt
  • Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2017) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer.
    Annet produkt
  • Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) Time series (2020) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from an USSIMO spectroradiometer.
    Annet produkt
  • Berge, Jørgen; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Johnsen, Geir. (2021) USSIMO spectroradiometer raw data time series (2018) measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway).
    Annet produkt
  • Johnsen, Geir; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan; Mckee, David; Kopec, Tomasz Piotr. (2021) Time series (2017) of irradiance in the PAR (photosynthetically active radiation) region measured under the dome of a light observatory in the Arctic (Ny-Ålesund, Svalbard, Norway) derived from SLR camera.
    Annet produkt
  • Faltynkova, Andrea; Johnsen, Geir; Wagner, Martin. (2021) Hyperspectral imaging as an emerging tool to analyze microplastics: A systematic review and recommendations for future development. Microplastics and Nanoplastics
    Vitenskapelig oversiktsartikkel/review

2020

  • Ramirez-Llodra, Eva; Hilário, Ana; Paulsen, Emil; Costa, Carolina; Bakken, Torkild; Johnsen, Geir. (2020) Benthic Communities on the Mohn’s Treasure Mound: Implications for Management of Seabed Mining in the Arctic Mid-Ocean Ridge. Frontiers in Marine Science
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir. (2020) Life and Light at the Dead of Night. Springer
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Johnsen, Geir; Zolich, Artur Piotr. (2020) Light in the Polar Night. Springer
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Mogstad, Aksel Alstad; Berge, Jørgen; Cohen, Jonathan H.. (2020) Operative Habitat Mapping and Monitoring in the Polar Night. Springer
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Berge, Jørgen; Johnsen, Geir. (2020) • Polar Night Exhibitions in Russia 2020. Kaliningrad – World Ocean Museum.
    Museumsutstilling
  • Gibbens, Sarah; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2020) As the Arctic warms, light pollution may pose a new treat to marine life. . National Geographic
    Intervju tidsskrift
  • Johnsen, Geir; Leu, Eva; Gradinger, Rolf. (2020) Marine Micro- and Macroalgae in the Polar Night. Springer
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Berge, Jørgen; Geoffroy, Maxime; Daase, Malin; Cottier, Finlo Robert; Priou, Pierre; Cohen, Jonathan H.. (2020) Artificial light during the polar night disrupts Arctic fish and zooplankton behavior down to 200 m depth. Communications Biology
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Polar night marine ecology - life and light in the dead of night. Springer Advances in Polar Ecology (0)
    Vitenskapelig antologi/Konferanseserie
  • Berge, Jørgen; Johnsen, Geir. (2020) Polar Night exhibition in Karelia (Petrozavodsk, Russia): 03.03 – 03.04.2020 . Polar Night exhibition, Karelia (Petrozavodsk, Russia). March-April 2020
    Museumsutstilling
  • Saad, Aya; Stahl, Annette; Våge, Andreas; Davies, Emlyn John; Nordam, Tor; Aberle-Malzahn, Nicole. (2020) Advancing Ocean Observation with an AI-driven Mobile Robotic Explorer. Oceanography
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Introduction. Springer
    Innledning
  • Fragoso, Glaucia Moreira; Johnsen, Geir; Chauton, Matilde Skogen; Cottier, Finlo Robert; Ellingsen, Ingrid H.. (2020) Phytoplankton community succession and dynamics using optical approaches. Continental Shelf Research
    Vitenskapelig artikkel
  • Mogstad, Aksel Alstad; Ødegård, Øyvind; Nornes, Stein Melvær; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan. (2020) Mapping the Historical Shipwreck Figaro in the High Arctic Using Underwater Sensor-Carrying Robots. Remote Sensing
    Vitenskapelig artikkel

2019

  • Fragoso, Glaucia Moreira; Davies, Emlyn John; Ellingsen, Ingrid H.; Chauton, Matilde Skogen; Fossum, Trygve Olav; Ludvigsen, Martin. (2019) Physical controls on phytoplankton size structure, photophysiology and suspended particles in a Norwegian biological hotspot. Progress in Oceanography
    Vitenskapelig artikkel
  • Kleiven, Wanda; Johnsen, Geir; Ardelan, Murat Van. (2019) Sea surface microlayer and elemental composition in phaeo-, chloro-, and rhodophytes in winter and spring. Journal of Phycology
    Vitenskapelig artikkel
  • Graham, Lisa Kristine Hernandez; Johnsen, Geir; Christensen-Dalsgaard, Signe. (2019) A pilot study assessing drones for mapping and monitoring of European shags. Institutt for biologi, NTNU
    Mastergradsoppgave
  • Mogstad, Aksel Alstad; Johnsen, Geir; Ludvigsen, Martin. (2019) Shallow-Water Habitat Mapping using Underwater Hyperspectral Imaging from an Unmanned Surface Vehicle: A Pilot Study. Remote Sensing
    Vitenskapelig artikkel
  • Kauko, Hanna Maria; Pavlov, Alexey; Johnsen, Geir; Granskog, Mats; Peeken, Ilka; Assmy, Philipp. (2019) Photoacclimation state of an Arctic underice phytoplankton bloom. Journal of Geophysical Research (JGR): Oceans
    Vitenskapelig artikkel
  • Pavlov, Alexey K.; Leu, Eva; Hanelt, Dieter; Bartsch, Inka; Karsten, Ulf; Hudson, Stephen. (2019) The Underwater Light Climate in Kongsfjorden and Its Ecological Implications. Springer
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Bazilchuk, Nancy Reney; Fossum, Trygve Olav; Fragoso, Glaucia Moreira; Ludvigsen, Martin; Johnsen, Geir. (2019) Smart undervannsrobot leter etter plankton. Av N Bazilchuk. Forskning.no. Angående NTNU Entice prosjekt publisert i Science Robotics. Forskning.no
    Populærvitenskapelig artikkel
  • Fossum, Trygve Olav; Fragoso, Glaucia Moreira; Davies, Emlyn John; Ullgren, Jenny; Mendes, Renato; Johnsen, Geir. (2019) Toward adaptive robotic sampling of phytoplankton in the coastal ocean. Science robotics
    Vitenskapelig artikkel
  • Fragoso, Glaucia Moreira; Poulton, Alex James; Pratt, Nicola Jane; Johnsen, Geir; Purdie, Duncan Alastair. (2019) Trait-based analysis of subpolar North Atlantic phytoplankton and plastidic ciliate communities using automated flow cytometer. Limnology and Oceanography
    Vitenskapelig artikkel

2018

  • Fragoso, Glaucia Moreira; Poulton, Alex J.; Yashayaev, Igor M.; Head, Erica J.H.; Johnsen, Geir; Purdie, Duncan A.. (2018) Diatom biogeography from the Labrador Sea revealed through a trait-based approach. Frontiers in Marine Science
    Vitenskapelig artikkel
  • Dumke, Ines; Nornes, Stein Melvær; Purser, Autun; Marcon, Yann; Ludvigsen, Martin; Ellefmo, Steinar Løve. (2018) First hyperspectral imaging survey of the deep seafloor: High-resolution mapping of manganese nodules. Remote Sensing of Environment
    Vitenskapelig artikkel
  • Zolich, Artur Piotr; De La Torre, Pedro R.; Rodwell, Shane; Geoffroy, Maxime; Johnsen, Geir; Berge, Jørgen. (2018) An ice-tethered buoy for fish and plankton research. IEEE conference proceedings
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Fjærtoft, Kaja Lønne; Bakken, Torkild; Johnsen, Geir; Ludvigsen, Martin. (2018) Macroalgal detritus: Physical variables and impacts on the benthic macrofaunal community. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin; Hansen, Roy Edgar; Maarleveld, Thijs. (2018) Towards Autonomous Operations and Systems in Marine Archaeology. Doktoravhandlinger ved NTNU (IMT-12)
    Doktorgradsavhandling
  • Strømsholm, Jørgen; Johnsen, Geir; Ludvigsen, Martin. (2018) Eyes beneath the surface - using a miniROV to reveal habitat and dietary choices of the European shag. NTNU MSc thesis
    Mastergradsoppgave
  • Kauko, Hanna Maria; Johnsen, Geir; Assmy, Phillipp. (2018) Light response and acclimation of macroalgae in a changing Arctic. Doktoravhandlinger ved NTNU (2018)
    Doktorgradsavhandling
  • Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning - enda en kilde til bekymring. Svalbardposten
    Kronikk
  • Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning truer livet i Arktis. Aftenposten Viten
    Kronikk
  • Ludvigsen, Martin; Berge, Jørgen; Geoffroy, Maxime; Cohen, Jonathan H.; De La Torre, Pedro R.; Nornes, Stein Melvær. (2018) Use of an autonomous surface vehicle reveals small-scale diel vertical migrations of zooplankton and susceptibility to light pollution under low solar irradiance. Science Advances
    Vitenskapelig artikkel
  • Nornes, Stein Melvær; Sørensen, Asgeir Johan; Ludvigsen, Martin; Johnsen, Geir; Schjølberg, Ingrid; Ånonsen, Kjetil Bergh. (2018) Guidance and Control of Marine Robotics for Ocean Mapping and Monitoring. Doktoravhandlinger ved NTNU (2018:202)
    Doktorgradsavhandling
  • Ødegård, Øyvind; Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging: a new tool for marine archaeology. Applied Optics
    Vitenskapelig artikkel
  • Fossum, Trygve Olav; Eidsvik, Jo; Ellingsen, Ingrid H.; Alver, Morten; Fragoso, Glaucia Moreira; Johnsen, Geir. (2018) Information-driven robotic sampling in the coastal ocean. Journal of Field Robotics (JFR)
    Vitenskapelig artikkel
  • Kauko, Hanna Maria; Olsen, Lasse Mork; Duarte, Pedro; Peeken, Ilka; Granskog, Mats A.; Johnsen, Geir. (2018) Algal colonization of young arctic sea ice in spring. Frontiers in Marine Science
    Vitenskapelig artikkel
  • Dumke, Ines; Purser, Autun; Marcon, Yann; Nornes, Stein Melvær; Johnsen, Geir; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging as an in situ taxonomic tool for deep-sea megafauna. Scientific Reports
    Vitenskapelig artikkel
  • Liefmann, Stephanie; Järnegren, Johanna; Johnsen, Geir; Murray, Fiona. (2018) Eco-physiological responses of cold-water soft corals to anthropogenic sedimentation and particle shape. Journal of Experimental Marine Biology and Ecology
    Vitenskapelig artikkel
  • Geoffroy, Maxime; Berge, Jørgen; Majaneva, Sanna Kristiina; Johnsen, Geir; Langbehn, Tom; Cottier, Finlo Robert. (2018) Increased occurrence of the jellyfish Periphylla periphylla in the European high Arctic. Polar Biology
    Short communication
  • Johnsen, Geir; Norli, Marit; Moline, Mark A.; Robbins, Ian; Quillfeldt, Cecilie von; Sørensen, Kai. (2018) The advective origin of an under-ice spring bloom in the Arctic Ocean using multiple observational platforms. Polar Biology
    Vitenskapelig artikkel
  • Dumke, Ines; Ludvigsen, Martin; Ellefmo, Steinar Løve; Søreide, Fredrik; Johnsen, Geir; Murton, Bramley J.. (2018) Underwater Hyperspectral Imaging Using a Stationary Platform in the Trans-Atlantic Geotraverse Hydrothermal Field. IEEE Transactions on Geoscience and Remote Sensing
    Vitenskapelig artikkel
  • Gabrielsen, Tove M.; Johnsen, Geir. (2018) Skogen på Svalbard. Svalbardposten
    Populærvitenskapelig artikkel

2017

  • Berge, Jørgen; Johnsen, Geir; Tandberg, Anne helene. (2017) Polar night - Life and light in the dead of night. Russian Science Week - Lomonosov Moscow State University
    Museumsutstilling
  • Otterlei, Inger; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin; Hareide, Nils Roar; Christensen-Dalsgaard, Signe. (2017) 300 000 sjøfugl er forsvunnet fra Runde. Sunnmørsposten
    Intervju tidsskrift
  • Mynors, Julie; Johnsen, Geir; Wernand, Marcel; Volent, Zsolt. (2017) Ocean Colour and Phytoplankton Dynamics - An examination of the Forel-Ule scale in a modern context. NTNU Trondheim
    Mastergradsoppgave
  • Johnsen, Geir; Christiansen, Hanne H; Ravolainen, Virve; Reymert, Per Kyrre; Jenssen, Eva Therese; Arlov, Thor Bjørn. (2017) Utfordrende natur og sikkerhet på Svalbard. Svalbardposten
    Kronikk
  • Kamilla, Sporsheim; Sporsheim, Kamilla; Johnsen, Geir; Reitan, Kjell Inge; Evertsen, Antii Jussi. (2017) Astaxanthin as a biomarker for fish feed loading in the marine ecosystem. NTNU, Trondheim
    Mastergradsoppgave
  • Kjeken, John; Johnsen, Geir; Ludvigsen, Martin; Thorsnes, Terje; Lågstad, Petter Arthur. (2017) The growth of benthic organisms in a dumping ground for military bombs and munitions. NTNU, Trondheim
    Mastergradsoppgave
  • Johnsen, Geir; Sandbu, Marthe; Assmy, Philipp. (2017) High Arctic Sea-Ice Algae: The Use of Rapid Light Curves to Assess Photosynthetic Performance of Different Ice-Algal Communities. Master science NTNU
    Mastergradsoppgave
  • Ostaszewska, Kaja; Balazy, Piotr; Berge, Jørgen; Johnsen, Geir; Staven, Robert. (2017) Seabirds during Arctic Polar Night: underwater observations from Svalbard archipelago, Norway. Waterbirds (De Leon Springs, Fla.)
    Vitenskapelig artikkel
  • Kauko, Hanna Maria; Taskjelle, Torbjørn; Assmy, Philipp; Pavlov, Alexey K.; Mundy, C.J.; Duarte, Pedro. (2017) Windows in Arctic sea ice: light transmission and ice algae in a refrozen lead. Journal of Geophysical Research (JGR): Biogeosciences
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir. (2017) Kunnskapshull om livet i Arktis i mørketiden. Aftenposten Viten
    Kronikk
  • Assmy, Philipp; Fernández-Méndez, Mar; Duarte, Pedro; Meyer, Amelie; Randelhoff, Achim; Mundy, Christopher John. (2017) Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ic. Scientific Reports
    Vitenskapelig artikkel
  • Mogstad, Aksel Alstad; Johnsen, Geir. (2017) Spectral characteristics of coralline algae: a multi-instrumental approach, with emphasis on underwater hyperspectral imaging. Applied Optics
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir. (2017) Om bambus, spøkelseskreps og et Arktis i endring. Svalbardposten
    Kronikk
  • Berge, Jørgen; Johnsen, Geir. (2017) Superkommunisten. Svalbardposten
    Kronikk
  • Andersson, Ingvild Henriette Kristin; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin. (2017) Bio-optical diversity on cold water coral habitats. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Alvsvåg, Dora Marie; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Berge, Jørgen. (2017) Mapping of a seagrass habitat in Hopavågen, Sør-Trøndelag, with the use of an Autonomous Surface Vehicle combined with optical techniques. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Paulsen, Emil; Bakken, Torkild; Ramirez-Llodra, Eva; Johnsen, Geir. (2017) Community structure and biodiversity of the benthic megafauna at the inactive hydrothermal site Mohn's Treasure, on the Mohn's Ridge, Arctic Mid-Ocean Ridge (AMOR) . Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave

2016

  • Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) Opp fra polarnattens mørke. Aftenposten Viten
    Kronikk
  • Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) A bitter-sweet symphony. Svalbardposten
    Kronikk
  • Gätzschmann, Per; Hårsaker, Karstein; Johnsen, Geir; Leite, Stein Roar; Pedersen, Solbjørg; Sørumgård, Marit. (2016) Nye oppdagelser i polarnatta - video. Polarnatt
    Museumsutstilling
  • Berge, Jørgen; Geoffroy, Maxime; Johnsen, Geir; Cottier, Finlo Robert; Bluhm, Bodil; Vogedes, Daniel Ludwig. (2016) Ice-tethered observational platforms in the Arctic Ocean pack ice. IFAC-PapersOnLine
    Vitenskapelig artikkel
  • Cronin, Heather; Cohen, Jonathan H.; Berge, Jørgen; Johnsen, Geir; Moline, Mark A.. (2016) Bioluminescence as an ecological factor during high Arctic polar night. Scientific Reports
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Ludvigsen, Martin; Cohen, Jonathan. (2016) Design for latskap - men med store muligheter. Svalbardposten
    Kronikk
  • Jakobsen, June; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Karlsen, Svein. (2016) The Tautra Cold-Water Coral Reef - Mapping and describing the biodiversity of a cold-water coral reef ecosystem in the Trondheimsfjord by use of multi-beam echo sounding and video mounted on a remotely operated vehicle. NTNU
    Mastergradsoppgave
  • Bondø, Tor-Hartvig; Johnsen, Geir; Berge, Jørgen. (2016) Fant yrende liv i polarnatta. VG : Verdens gang
    Populærvitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir. (2016) Mørkets fyrster med påskrudd lys. Svalbardposten
    Populærvitenskapelig artikkel
  • Bazilchuk, Nancy Reney; Leite, Stein Roar; Johnsen, Geir; Kjeken, John; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2016) Bomber og buss på havbunnen. Gemini
    Populærvitenskapelig artikkel
  • Haudemann-Andersen, Jørn; Lystad, M S; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen. (2016) Blå lys i det kalde dyp. NRK Trøndelag, Nyheter
    Populærvitenskapelig artikkel
  • Haugstad, Tor; Erdal, Ivar; Johnsen, Geir; Sørensen, Asgeir Johan; Fjærvik, Nils. (2016) Gründerne mener dette kameraet kan bli det nye ekkoloddet – Ecotone er kandidat til TU Tech Award. Teknisk Ukeblad
    Populærvitenskapelig artikkel
  • Bjørgan, Espen Halvorsen; Johnsen, Geir; Kjeken, Jon; Ludvigsen, Martin. (2016) Fant buss på 600 m dybde. Adresseavisen
    Populærvitenskapelig artikkel
  • Håpnes, Sverre Julian; Johnsen, Geir; Ludvigsen, Martin; Lågstad, Petter Arthur. (2016) Mapping of demersal fish and benthos by AUV equipped with optical and acoustic imagers at 600 m depth in Trondheimsfjorden. NTNU MSc
    Mastergradsoppgave
  • Liefmann, Stephanie; Johnsen, Geir; Järnegren, Johanna. (2016) Eco-physiological responses of cold-water corals to anthropogenic sedimentation and particle shape. NTNU Mastergrad
    Mastergradsoppgave
  • Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Sørumgård, Marit; Sandbakk, Elin; Johnsen, Tobias Kvendseth. (2016) Polarnatt/Polar Night - ny utstilling med nyheter fra 2015-2016. Polarnattsutstilling ved Vitenskapsmuseet NTNU
    Museumsutstilling
  • Johnsen, Geir; Ludvigsen, Martin; Sørensen, Asgeir Johan; Aas, Lars Martin Sandvik. (2016) The use of underwater hyperspectral imaging deployed on remotely operated vehicle – methods and applications. IFAC-PapersOnLine
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Kinderegg i polarnatten. Svalbardposten
    Kronikk
  • Donahue, Michelle; Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) The age of humans - living in the anthropocene - "Termites of the sea" found munching wood near Arctic shipwrecks. Smithsonian
    Populærvitenskapelig artikkel
  • Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Dark lords, werewolves and Indiana Jones in the polar night. Gemini (English edition)
    Intervju tidsskrift
  • Krüger, Frida Jørstad; Johnsen, Geir; Kjeken, John; Ludvigsen, Martin. (2016) Gammel buss ble korallrev. NRK Viten
    Populærvitenskapelig artikkel
  • Kokkegård, Hanne; Johnsen, Geir; Ludvigsen, Martin; Torre, Pedro De La. (2016) Vitenskab - Bomber fra 2 verdenskrig danner koralrev på 600 m dybde. Danmarks radio
    Populærvitenskapelig artikkel
  • Haugstad, Tormod; Erdal, Ivar; Johnsen, Geir. (2016) Kameraet deres «kan bli det nye ekkoloddet». Nå er det norske selskapet i ferd med å lykkes. Teknisk Ukeblad
    Intervju tidsskrift
  • Johnsen, Geir. (2016) Yrende liv i Isfjorden. Svalbardposten
    Populærvitenskapelig artikkel
  • Aarskog, Karine Nigar; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2016) Et stort løft for arktisk forskning (NTNU & UiT). Universitetet i Tromsø
    Fagartikkel
  • Berge, Jørgen; Falk-Petersen, Stig; Renaud, Paul E.; Daase, Malin; Geoffroy, Maxime; Johnsen, Geir. (2016) En reise mot Ultima Thule. Svalbardposten
    Populærvitenskapelig artikkel
  • Lervik, Frank; Johnsen, Geir; Ludvigsen, Martin; Kjeken, John. (2016) Det ligger flere busser der. Adresseavisen
    Populærvitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Mark spiser opp vrak på havbunnen. Fiskaren
    Populærvitenskapelig artikkel
  • Kintisch, Eli; Berge, Jørgen; Last, Kim; Cohen, Jonathan; Johnsen, Geir. (2016) Voyage into darkness . Science
    Intervju tidsskrift
  • Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Ludvigsen, Martin; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Mørkets fyrster, varulver og Indiana Jones. Gemini
    Populærvitenskapelig artikkel
  • Berge, Jørgen; Renaud, Paul E.; Johnsen, Geir; Darnis, Gerald; Geoffroy, Maxime; Daase, Malin. (2016) I grenselandet (mellom Tull og Thule). Svalbardposten
    Populærvitenskapelig artikkel
  • Førde, Henny; Forbord, Silje; Handå, Aleksander; Fossberg, Julia; Arff, Johanne; Johnsen, Geir. (2016) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. Journal of Applied Phycology
    Vitenskapelig artikkel

2015

  • Nilssen, Ingunn; Dos Santos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral, Marcelo M.; Eide, Ingvar. (2015) Assessing the potential impact of water-based drill cuttings on deep water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
    Vitenskapelig artikkel
  • Nilssen, Ingunn; Santos dos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral Montenegro, Marcelo; Eide, Ingvar. (2015) Assessing the potential impact of water-based drill cuttings on deep-water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan; Nilssen, Ingunn. (2015) Enabling technology for Arctic research. Pan European Networks: Science and Techology Magazine
    Vitenskapelig oversiktsartikkel/review
  • Rodriguez, Francisco; Garrido, J.L.; Sabrino, C; Johnsen, Geir; Riobo, P; Franco, J. (2015) Divinyl chlorophyll a in the marine eukaryotic protist Alexandrium ostenfeldii (Dinophyceae). Environmental Microbiology
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Aarekol, Lena. (2015) Life and light in the dead of night. Museumsutstilling
    Museumsutstilling
  • Nilssen, Ingunn; Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Moline, Mark A.; Berge, Jørgen. (2015) Integrated environmental mapping and monitoring, a methodological approach to optimise knowledge gathering and sampling strategy. Marine Pollution Bulletin
    Vitenskapelig artikkel
  • Aarekol, Lena; Johnsen, Geir; Berge, Jørgen. (2015) Polarnatt. Liv og lys i mulm og mørke Polarnighth. Life and death in dead of night. Utstilling
    Museumsutstilling
  • Ludvigsen, Martin; Thorsnes, Terje; Hansen, Roy Edgar; Sørensen, Asgeir Johan; Johnsen, Geir; Lågstad, Petter Arthur. (2015) Underwater vehicles for environmental management in coastal areas. IEEE conference proceedings
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Tandberg, Anne Helene S.; Berge, Jørgen; Johnsen, Geir; Aarekol, Lena. (2015) POLARNATT - liv og lyst i mulm og mørke. Polarnatt - liv og lyst i mulm og mørke
    Museumsutstilling
  • Berge, Jørgen; Johnsen, Geir. (2015) Polarnatt - Liv og lys i mulm og mørke Polar night - life and light in the dead of night. Utstilling på Polarmuseet i Tromsø
    Museumsutstilling
  • Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Sørensen, Asgeir Johan; Last, Kim; Falk-Petersen, Stig. (2015) Is ambient light during the high Arctic polar night sufficient to act as a visual cue for zooplankton?. PLOS ONE
    Vitenskapelig artikkel
  • Berge, Jørgen; Renaud, Paul; Darnis, Gérald; Cottier, Finlo; Last, Kim; Gabrielsen, Tove M.. (2015) In the dark: a review of ecosystem processes during the Arctic polar night. Progress in Oceanography
    Vitenskapelig artikkel
  • Berge, Jørgen; Daase, Malin; Renaud, Paul; Ambrose, William G. Jr.; Darnis, Gérald; Last, Kim S. (2015) Unexpected levels of biological activity during the polar night offer new perspectives on a warming Arctic. Current Biology
    Vitenskapelig artikkel

2014

  • Pettersen, Ragnhild; Johnsen, Geir; Bruheim, Per; Andreassen, Trygve. (2014) Development of hyperspectral imaging as a bio-optical taxonomic tool for pigmented marine organisms. Organisms Diversity & Evolution
    Vitenskapelig artikkel
  • Valle, Kristin Collier; Nymark, Marianne; Aamot, Inga; Hancke, Kasper; Winge, Per; Andresen, Kjersti. (2014) System responses to equal doses of photosynthetically usable radiation of blue, green, and red light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
    Vitenskapelig artikkel
  • Lund, Lene; Johnsen, Geir; Bakken, Torkild; Gabrielsen, Tove. (2014) Morphological diversity in Laminaria digitata - different species or different phenotypes?. Norwegian University of Science and Technology, Department of Biology
    Mastergradsoppgave
  • Valle, Kristin Collier; Johnsen, Geir; Bones, Atle M. (2014) Photoacclimation mechanisms and light responses in marine micro- and macroalgae. NTNU
    Doktorgradsavhandling
  • Hallerud, Charlotte; Johnsen, Geir; Aamot, Inga. (2014) Pigment composition of macroalgae from a Norwegian kelp forest. NTNU
    Mastergradsoppgave
  • Kjerstad, Ingrid; Johnsen, Geir; Sørensen, Asgeir Johan; Bakken, Torkild. (2014) Underwater Imaging and the effect of Inherent Optical Properties on image quality. NTNU
    Mastergradsoppgave
  • Førde, Henny; Reitan, Kjell Inge; Johnsen, Geir. (2014) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. NTNU
    Mastergradsoppgave
  • Hatlebakk, Maja; Johnsen, Geir; Søreide, Janne. (2014) Effect of lipids and fatty acid composition on success of reproduction in Calanus glacialis. NTNU
    Mastergradsoppgave
  • Ødegård, Øyvind; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan; Dukan, Fredrik. (2014) Managing data from multiple sensors in an interdisciplinary research cruise. Amsterdam University Press
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Kleiven, Wanda; Johnsen, Geir; Ardelan, Murat Van. (2014) Elemental composition in various marine brown, green and red macro algae with respect to season and tissue age. NTNU
    Mastergradsoppgave
  • Kvernvik, Ane Cecilie; Johnsen, Geir; Aamot, Inga. (2014) How lamina age influence photosynthetic response to light variations in Saccharina latissima. NTNU
    Mastergradsoppgave
  • Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Lågstad, Petter Arthur; Ødegård, Øyvind. (2014) Scientific Operations Combining ROV and AUV in the Trondheim Fjord. Marine Technology Society journal
    Vitenskapelig artikkel
  • Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Glowing in the dark: Discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
    Vitenskapelig artikkel
  • Hansen, Ingrid; Pettersen, Ragnhild; Beuchel, Frank; Cochrane, Sabine; Frantzen, marianne; Ekehaug, Stefan. (2014) Underwater hyperspectral imaging (UHI) for environmental mapping and monitoring of seabed habitats. Ocean Optics
    Sammendrag/abstract
  • Cohen, Jonathan; Cronin, Heather; Moline, Mark A.; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Are krill eyes useful in the high Arctic polar night?. Ocean Optics
    Sammendrag/abstract
  • Johnsen, Geir; Ekehaug, Stefan; Hansen, Ingrid; Sørensen, Asgeir Johan. (2014) The use of underwater hyperspectral imaging deployed on remotely operated vehicles to identify, map and monitor bio-geo-chemical objects of interest. Ocean Optics
    Sammendrag/abstract
  • Aamot, Inga; Pokrzywinski, Kaytee; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan. (2014) Light Climate and Status of the Photosynthetic Machinery in Macroalgae in the Polar Night. Ocean Optics
    Sammendrag/abstract
  • Nornes, Stein Melvær; Candeloro, Mauro; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Photomosaic camera as simultaneous data collector and navigation aid on unmanned underwater vehicles. Ocean Optics
    Sammendrag/abstract
  • Nilssen, Ingunn; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen; Nornes, Stein Melvær. (2014) Integrated environmental monitoring; a methodological approach to optimise knowledge gathering and sampling strategy. Ocean Optics
    Sammendrag/abstract
  • Bones, Atle M.; Johnsen, Geir; Brembu, Tore; Valle, Kristin Collier. (2014) Photoacclimation mechanisms and light responses in marine micro- and macroalgae. Doktoravhandlinger ved NTNU (74)
    Doktorgradsavhandling
  • Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Erratum to: Glowing in the dark: discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
    Errata
  • Berge, Jørgen; Cottier, Finlo; Varpe, Øystein; Renaud, Paul; Falk-Petersen, Stig; Kwasniewski, Sawomir. (2014) Arctic complexity: A case study on diel vertical migration of zooplankton. Journal of Plankton Research
    Vitenskapelig artikkel
  • Eldevik, Tor; Reigstad, Marit; Falck, Eva; Gerland, Sebastian; Jentoft, Sissel; Johnsen, Geir. (2014) Arven efter Nansen. Forskningsplan for det sentrale og nordlige Barentshavet. UiT Norges arktiske universitet UiT Norges arktiske universitet
    Rapport
  • Hancke, Kasper; Hovland, Erlend Kjeldsberg; Volent, Zsolt; Pettersen, Ragnhild; Johnsen, Geir; Moline, Mark A.. (2014) Optical properties of CDOM across the Polar Front in the Barents Sea: Origin, distribution and significance. Journal of Marine Systems
    Vitenskapelig artikkel
  • Hovland, Erlend Kjeldsberg; Hancke, Kasper; Alver, Morten; Drinkwater, Kennneth F.; Høkedal, Jo; Johnsen, Geir. (2014) Optical impact of an Emiliania huxleyi bloom in the frontal region of the Barents Sea. Journal of Marine Systems
    Vitenskapelig artikkel

2013

  • Ingrid, Hansen; Johnsen, Geir; Sørensen, Asgeir Johan. (2013) Optical Mapping of Cold-water Corals in Trondheimsfjorden and Svalbard. NTNU
    Mastergradsoppgave
  • Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan. (2013) The use of side scan and synthetic aperture sonar mounted on autonomous underwater vehicles for biological habitat mapping. MSc Thesis (2013)
    Mastergradsoppgave
  • Båtnes, Anna Solvang; Miljeteig, Cecilie; Berge, Jørgen; Greenacre, Michael; Johnsen, Geir. (2013) Quantifying the light sensitivity of Calanus spp. during the polar night: potential for orchestrated migrations conducted by ambient light from the sun, moon, or aurora borealis. Polar Biology
    Vitenskapelig artikkel
  • Pettersen, Ragnhild; Johnsen, Geir. (2013) Identification of marine organisms using Chemotaxonomy and Hyperspectral imaging. Doktoravhandlinger ved NTNU (292)
    Doktorgradsavhandling
  • Båtnes, Anna Solvang; Johnsen, Geir. (2013) Light in the dark – the role of irradiance in the high Arctic marine ecosystem during polar night. Doktoravhandlinger ved NTNU (151)
    Doktorgradsavhandling
  • Johnsen, Geir; Volent, Zsolt; Dierssen, Heidi; Pettersen, Ragnhild; Ardelan, Murat Van; Søreide, Fredrik. (2013) Underwater hyperspectral imagery to create biogeochemical maps of seafloor properties. Woodhead Publishing Limited
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Ludvigsen, Martin; Johnsen, Geir; Lågstad, Petter Arthur; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2013) Scientific operations combining ROV and AUV in the Trondheim Fjord. IEEE conference proceedings
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Bones, Atle M.; Johnsen, Geir; Brembu, Tore; Nymark, Marianne. (2013) Light responses in the marine diatom Phaeodactylum tricornutum. Doktoravhandlinger ved NTNU (378)
    Doktorgradsavhandling
  • Berge, Jørgen; Johnsen, Geir; Falk-Pettersen, Stig. (2013) Mørkets hemmeligheter. Svalbardposten
    Populærvitenskapelig artikkel
  • Nymark, Marianne; Valle, Kristin Collier; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir. (2013) Molecular and photosynthetic responses to prolonged darkness and subsequent acclimation to re-illumination in the diatom Phaeodactylum tricornutum. PLOS ONE
    Vitenskapelig artikkel
  • Hovland, Erlend Kjeldsberg; Dierssen, Heidi; Ferreira, Ana Sofia; Johnsen, Geir. (2013) Dynamics regulating major trends in Barents Sea temperatures and subsequent effect on remotely sensed particulate inorganic carbon. Marine Ecology Progress Series
    Vitenskapelig artikkel

2012

  • Bjørdalsbakke, Lise Kristin; Johnsen, Geir; Bakken, Torkild; Berge, Jørgen. (2012) Population structure, parasitism and prey preference in Sclerocrangon boreas and S. ferox, Svalbard. NTNU
    Hovedfagsoppgave
  • Hovland, Erlend Kjeldsberg; Johnsen, Geir; Sakshaug, Egil; Folkestad, Are. (2012) Bio-optics and ecology in Emiliania huxleyi blooms: Field and remote sensing studies in Norwegian water. NTNU
    Doktorgradsavhandling
  • Berge, Jørgen; Båtnes, Anna Solvang; Johnsen, Geir; Blackwell, Susan; Moline, Mark A.. (2012) Bioluminescence in the high Arctic during the polar night. Marine Biology
    Vitenskapelig artikkel
  • Belseth, Elen; Johnsen, Geir; Berge, Jørgen. (2012) Eco-physiology of the Arctic kelp Laminaria solidungula. NTNU Master thesis
    Mastergradsoppgave
  • Fremstedal, Ane Sofia Viset; Bruheim, Per; Sletta, Håvard; Johnsen, Geir. (2012) Utvikling og optimalisering av protokoll for massespektrometrisk metabolsk profilering av adherente humane celler. NTNU Master theses
    Mastergradsoppgave
  • Gabrielsen, Tove M; Quillfeldt, Cecilie von; Johnsen, Geir; Berge, Jørgen. (2012) Varm vinter, sen vår i fjorden. Svalbardposten
    Leserinnlegg
  • Elde, Anette; Pettersen, Ragnhild; Bruheim, Per; Järnegren, Johanna; Johnsen, Geir. (2012) Pigmentation and Spectral Absorbance Signatures in Deep-Water Corals from the Trondheimsfjord, Norway. Marine Drugs
    Vitenskapelig artikkel
  • Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2012) Phytoplankton Pigments: Characterization, Chemotaxonomy and Applications in Oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2012)
    Vitenskapelig antologi/Konferanseserie

2011

  • Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2011) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
    Vitenskapelig artikkel
  • Andersen, Hanne Kile; Johnsen, Geir; Bakken, Torkild. (2011) Gastropods Associated with Laminaria hyperborea and Saccorhiza polyschides in a Norwegian Kelp Forest: Comparison of Sampling and In Situ Imaging Techniques. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Brunet, Christophe; Johnsen, Geir; Lavaud, Johan; Roy, Suzanne. (2011) Pigments and photoacclimation processes. Cambridge University Press
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Bricaud, Annick; Nelson, Norman; Prézelin, Barbara; Bidigare, Robert. (2011) In vivo bio-optical properties of phytoplankton pigments. Cambridge University Press
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Volent, Zsolt; Johnsen, Geir; Hovland, Erlend Kjeldsberg; Folkestad, Are; Olsen, Lasse Mork; Tangen, Karl. (2011) Improved monitoring of phytoplankton bloom dynamics in a Norwegian fjord by integrating satellite data, pigment analysis, and Ferrybox data with a coastal observation network. Journal of Applied Remote Sensing
    Vitenskapelig artikkel
  • Johnsen, Geir; Moline, Mark; Pettersson, Lasse H.; Pinckney, J. L.; Pozdnyakov, Dmitry; Egeland, Einar Skarstad. (2011) Optical monitoring of phytoplankton bloom pigment signatures. Cambridge University Press
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Llewellyn, Carole A.; Roy, Suzanne; Johnsen, Geir; Egeland, Einar Skarstad; Chauton, Matilde ; Hallegraeff, Gustaff. (2011) Perspectives on future directions. Cambridge University Press
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Preface. Cambridge University Press
    Forord
  • Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Acknowledgements. Cambridge University Press
    Annet
  • Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Phytoplankton pigments : characterization, chemotaxonomy and applications in oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2011)
    Vitenskapelig antologi/Konferanseserie
  • Jouenne, Fabien; Eikrem, Wenche; Le Gall, F; Marie, Dominique; Johnsen, Geir; Vaulot, Daniel. (2011) Prasinoderma singularis sp. nov. (Prasinophyceae, Chlorophyta), a Solitary Coccoid Prasinophyte from the South-East Pacific Ocean. Protist
    Vitenskapelig artikkel
  • Pettersen, Ragnhild; Johnsen, Geir; Berge, Jørgen; Hovland, Erlend Kjeldsberg. (2011) Phytoplankton chemotaxonomy in waters around the Svalbard archipelago reveals high amounts of Chl b and presence of gyroxanthin-diester. Polar Biology
    Vitenskapelig artikkel

2010

  • Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2010) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
    Vitenskapelig artikkel
  • Aamot, Inga; Berge, Jørgen; Hancke, Kasper; Johnsen, Geir; Moline, Mark; Schofield, Oscar. (2010) NORUS - Technology Development for Marine Monitoring and Ocean Observation:An North America-Norway educational program. http://ipy-osc.no/abstract/
    Sammendrag/abstract
  • Johnsen, Geir; Søreide, Fredrik. (2010) Underwater hyperspectral imaging of marine mineral deposits. Underwater Mining meeting Institute (UMI)
    Sammendrag/abstract

2009

  • Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit M.. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
    Fagbok
  • Johnsen, Geir; Nepstad, Ina. (2009) Cloning and characterisation of interleukin-6 and interleukin-11b in Atlantic halibut (Hippoglossus hippoglossus). NTNU, Institutt for biologi
    Mastergradsoppgave
  • Elde, Anette Cecilie; Johnsen, Geir. (2009) Pigmentation in deep-water corals from the Trondheimsfjord, Norway. NTNU, Institutt for biologi
    Mastergradsoppgave
  • Thoen, Hanne Halkinrud; Johnsen, Geir. (2009) Pigmentation in the Arctic deep-sea amphipods Eurythenes gryllus and Anonyx sp. NTNU, Institutt for biologi
    Mastergradsoppgave
  • Øye, Ane-Marte; Johnsen, Geir. (2009) Photobioreactor time-series of a simulated bloom of Emiliania huxleyi. NTNU, Institutt for biologi
    Mastergradsoppgave
  • Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
    Vitenskapelig antologi/Konferanseserie
  • Johnsen, Geir; Volent, Z; Sakshaug, E.; Sigernes, Fred; Pettersson, L.H.. (2009) Remote sensing in the Barents Sea. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Sakshaug, E.; Johnsen, Geir; Kristiansen, Svein; Quillfeldt, C.v.; Rey, F.; Slagstad, D.. (2009) Phytoplankton and primary production. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Sakshaug, E.; Johnsen, Geir; Volent, Z. (2009) Light. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Quillfeldt, C.v.; Hegseth, E.N.; Johnsen, Geir; Sakshaug, E.; Syvertsen, E.E.. (2009) Ice algae. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • von Quillfeldt, Cecilie H.; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik. (2009) Ice algae. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • von Quillfeldt, Cecilie; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik E.. (2009) Ice algae. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Sakshaug, Egil; Johnsen, Geir; Kristiansen, Svein; von Quillfeldt, Cecilie; Rey, Francisco; Slagstad, Dag. (2009) Phytoplankton and primary production. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Sakshaug, Egil; Johnsen, Geir; Volent, Z.. (2009) Light. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Volent, Zsolt; Sakshaug, Egil; Sigernes, Fred; Pettersson, Lasse H.. (2009) Remote sensing in the Barents Sea. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Sakshaug, E.; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
    Lærebok
  • Berge, Jørgen; Cottier, Finlo; Last, Kim S.; Varpe, Øystein; Leu, Eva; Søreide, Janne. (2009) Diel vertical migration of Arctic zooplankton during the polar night. Biology Letters
    Vitenskapelig artikkel
  • Nymark, Marianne; Valle, Kristin Collier; Brembu, Tore; Winge, Per; Hancke, Kasper; Andresen, Kjersti. (2009) An integrated analysis of molecular acclimation to high light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
    Vitenskapelig artikkel
  • Berge, Jørgen; Lønne, Ole Jørgen; Renaud, Paul; Johnsen, Geir; Gulliksen, Bjørn; Varpe, Øystein. (2009) Polartorsken - vil den bli utkonkurrert av sørlige fiskearter?. Svalbardposten
    Populærvitenskapelig artikkel
  • Evertsen, Jussi; Johnsen, Geir. (2009) In vivo and in vitro differences in chloroplast functionality in the two north Atlantic sacoglossans (Gastropoda, Opisthobranchia) Placida dendritica and Elysia viridis. Marine Biology
    Vitenskapelig artikkel
  • Volent, Z; Johnsen, Geir; Sigernes, Fred. (2009) Microscopic hyperspectral imaging used as a bio-optical taxonomic tool for micro- and macroalgae. Applied Optics
    Vitenskapelig artikkel

2008

  • Båtnes, Anna Solvang; Johnsen, Geir. (2008) Trophic interaction between little auks and their zooplankton prey in a high Arctic fjord based on lipid analyses. NTNU, Institutt for biologi
    Mastergradsoppgave
  • Hancke, Torunn Beate; Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2008) Rate of O2 production derived from pulse-amplitude-modulated fluorescence: Testing three biooptical approaches against measured O2-production rate. Journal of Phycology
    Vitenskapelig artikkel
  • Bredholt, Harald; Fjærvik, Espen; Johnsen, Geir; Zotchev, Sergey. (2008) Actinomycetes from sediments in the Trondheim Fjord, Norway: Diversity and biological activity. Marine Drugs
    Vitenskapelig artikkel
  • Bakken, Torkild; Evertsen, Jussi; Johnsen, Geir. (2008) Vitenskapelig dykking - behov for endringer i forskriften. Dykkenytt : informasjonsorgan for dykkeindustrien
    Fagartikkel
  • Hancke, Kasper; Hancke, Torunn Beate; Olsen, Lasse Mork; Johnsen, Geir; Glud, RN. (2008) Temperature effects on microalgal photosynthesis-light responses measured by O2 production, pulse-amplitude-modulated fluorescence, and C-14 assimilation. Journal of Phycology
    Vitenskapelig artikkel
  • Hovland, Erlend Kjeldsberg; Johnsen, Geir; Moline, Mark. (2008) Combined use of AUV and hyperspectral imaging to mapping sea-surface and macroalgae. Ocean Optics
    Sammendrag/abstract

2007

  • Kleiven, Mona; Johnsen, Geir. (2007) Pigmentation in Halocynthia pyriformis from Isfjorden, Spitsbergen. NTNU, Institutt for biologi
    Mastergradsoppgave
  • Hovland, Erlend Kjeldsberg; Sakshaug, Egil; Johnsen, Geir. (2007) Tracing Coccolithophorid Blooms in the Barents Sea Using MODIS Level-3 Imagery. NTNU, Institutt for biologi
    Mastergradsoppgave
  • Stübner, Eike; Johnsen, Geir. (2007) Biogeographical distribution of temperate vs. Arctic benthic species around Svalbard. NTNU, Institutt for biologi
    Mastergradsoppgave
  • Pettersen, Ragnhild; Johnsen, Geir. (2007) Phytoplankton systematics and pigmentation in the Arctic. NTNU, Institutt for biologi
    Mastergradsoppgave
  • Hancke, Kasper; Johnsen, Geir. (2007) Photosynthetic responses as a function of light and temperature: Field and laboratory studies on marine microalgae. NTNU, Institutt for biologi
    Doktorgradsavhandling
  • Johnsen, Geir; Volent, Zsolt; Sigernes, F.. (2007) Fine scale studies using hyper-spectral remote sensing. ESSAS Meeting in Marine Arctic Climate
    Rapport
  • Elvestrand, Jostein; Johnsen, Geir; Sneli, Jon-Arne. (2007) Morphometry and patterns of growth in Acesta excavata (Bivalvia: Limidae) from the Trondheimsfjord, Norway. NTNU, Institutt for biologi
    Hovedfagsoppgave
  • Cibic, Tamara; Blasutto, Oriana; Hancke, Kasper; Johnsen, Geir. (2007) Microphytobenthic species composition, pigment concentration, and primary production in sublittoral sediments of the Trondheimsfjord (Norway). Journal of Phycology
    Vitenskapelig artikkel
  • Evertsen, Jussi; Burghardt, Ingo; Johnsen, Geir; Wägele, Heike. (2007) Retention of functional chloroplasts in some sacoglossans from the Indo-Pacific and Mediterranean. Marine Biology
    Vitenskapelig artikkel
  • Ludvigsen, Martin; Sortland, Bjørn; Johnsen, Geir; Singh, Hanumant. (2007) Applications of Geo-Referenced Underwater Photo Mosaics in Marine Biology and Archaeology. Oceanography
    Vitenskapelig artikkel
  • Johnsen, Geir; Sakshaug, Egil. (2007) Biooptical characteristics of PSII and PSI in 33 species (13 pigment groups) of marine phytoplankton, and the relevance for pulse-amplitude-modulated and fast-repetition-rate fluorometry. Journal of Phycology
    Vitenskapelig artikkel
  • Edvardsen, B; Eikrem, W; Shalchian-Tabrizi, K; Riisberg, I; Johnsen, Geir; Naustvoll, L. (2007) Verrucophora farcimen gen. et sp nov (Dictyochophyceae, Heterokonta) - A bloom-forming ichthyotoxic flagellate from the Skagerrak, Norway. Journal of Phycology
    Vitenskapelig artikkel
  • Johnsen, Geir; Volent, Zsolt; Sigernes, F.; Berge, Jørgen; Hovland, Erlend Kjeldsberg; Sakshaug, Egil. (2007) Local hyperspectral imaging of ocean colour from tethered balloons in the Arctic. In Proceedings from Arctic Frontiers: Balancing human use and ecosystem protection. UiT Norges arktiske universitet UiT Norges arktiske universitet
    Rapport
  • Berge, Jørgen; Schander, C; Pampanin, D.M.; Johnsen, Geir. (2007) The past, present and future of the Mytilus edulis population on Svalbard. In Proceedings from Arctic Frontiers: Balancing human use and ecosystem protection. UiT Norges arktiske universitet UiT Norges arktiske universitet
    Rapport
  • Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2007) Bio-optical properties and spectral attenuation of photosynthetically available radiation: relation to primary productivity and phytoplankton composition. In Proceedings from Arctic Frontiers: balancing human use and ecosystem protection. UiT Norges arktiske universitet UiT Norges arktiske universitet
    Rapport
  • Johnsen, Geir. (2007) Arctic Life: Bridging ecosystem function using remote sensing technologies. Svalbard Science Forum
    Populærvitenskapelig artikkel
  • Carlsen, BP; Johnsen, Geir; Berge, Jørgen; Kuklinski, P. (2007) Biodiversity patterns of macro-epifauna on different lamina parts of Laminaria digitata and Saccharina latissima collected during spring and summer 2004 in Kongsfjorden, Svalbard. Polar Biology
    Vitenskapelig artikkel
  • Volent, Z; Johnsen, Geir; Sigernes, Fred. (2007) Kelp forest mapping by use of airborne hyperspectral imager. Journal of Applied Remote Sensing
    Vitenskapelig artikkel

2006

  • Sylling, Guro; Thingstad, Per Gustav; Johnsen, Geir. (2006) Marin bunndyrfauna (Gastropoda, Bivalvia) - Konsekvenser av åpning av veifylling over Ramsarområdet Tautrasvaet. NTNU, Institutt for biologi
    Mastergradsoppgave
  • Carlsen, Beth Paludan; Johnsen, Geir. (2006) Makroepifauna associeret med Laminaria digitata og L. saccharina, Svalbard. NTNU, Institutt for biologi
    Mastergradsoppgave
  • Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
    Leder
  • Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag; Pampanin, Daniella. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Olsen, Lasse Mork; Öztürk, M.; Sakshaug, Egil; Johnsen, Geir. (2006) Photosynthesis-induced phosphate precipitation in seawater: ecological implications for phytoplankton. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Rodriguez, F; Chauton, Matilde Skogen; Johnsen, Geir; Andresen, Kjersti; Olsen, Lasse Mork; Zapata, M.. (2006) Photoacclimation in phytoplankton: implications for biomass estimates, pigment functionality and chemotaxonomy. Marine Biology
    Vitenskapelig artikkel
  • Roy, Suzanne; Egeland, Einar Skarstad; Johnsen, Geir; Llewellyn, Carole; Wright, Simon. (2006) Report of a Workshop on a Follow-Up Volume of the Book "Phytoplankton Pigments in Oceanography". Scientific Committee on Oceanic Research
    Rapport
  • Johnsen, Geir. (2006) Warming Arctic sees return of blue mussels after 1000 years. National Geographic
    Populærvitenskapelig artikkel
  • Onstad, L; Evertsen, Jussi; Johnsen, Geir. (2006) Snegle på solceller. Gemini
    Populærvitenskapelig artikkel

2005

  • Hilstad, Kari; Johnsen, Geir. (2005) In situ tidsseriemålinger av lyshøstingsegenskaper og cellekjemi hos marine makroalger i Trondheimsfjorden. NTNU, Institutt for biologi
    Hovedfagsoppgave
  • Olsen, Lasse Mork; Johnsen, Geir. (2005) Interactions between marine osmo- and phagotrophs in different physicochemical environments. NTNU, Institutt for biologi
    Doktorgradsavhandling
  • Valle, Kristin Collier; Johnsen, Geir. (2005) Detection of monthly variation in marine red, brown and green macroalgae by means of in situ video, epifluorescence microscopy and numerical digital image analysis. NTNU, Institutt for biologi
    Hovedfagsoppgave
  • Chauton, Matilde Skogen; Johnsen, Geir; Sakshaug, Egil. (2005) Nuclear Magnetic Resonance spectroscopy of marine microalgae: Metabolic profiling and species discrimination from High-resolution Magic Angle Spinning NMR analysis of whole-cell samples. NTNU, Institutt for biologi
    Doktorgradsavhandling
  • Sakshaug, Egil; Johnsen, Geir. (2005) Absorption, fluorescence excitation and photoacclimation in phytoplankton. Multi-Science Publishing
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2005) Ocean temperature oscillations enable reappearance of blue mussels Mytilus edulis in Svalbard after 1000 year absence. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Sakshaug, Egil; Johnsen, Geir. (2005) Algal cultures, Analogues of Blooms and Applications. Multi-Science Publishing Multi-Science Publishing
    Vitenskapelig antologi/Konferanseserie
  • Berge, J; Johnsen, Geir; Nilsen, F; Gulliksen, B; Slagstad, D. (2005) Ocean temperature oscillations causes the reappearance of blue mussels in Svalbard after 1000 years of absence. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Bordvik, Hans Otto; Johnsen, Geir. (2005) “En glupsk nellik”. NEWTON websider (NRK)
    Populærvitenskapelig artikkel
  • Indergaard, M; Nordtvedt, M; Johnsen, Geir. (2005) Satellittmålinger for miljøet (SISCAL project, NTNU, IBI). Gemini
    Populærvitenskapelig artikkel
  • Bordvik, Hans Otto; Johnsen, Geir. (2005) “Forskning og foto under vann”. NEWTON websider (NRK)
    Populærvitenskapelig artikkel
  • Burghardt, Ingo; Evertsen, Jussi; Johnsen, Geir; Wägele, Heike. (2005) Solar powered seaslugs - Mutualistic symbiosis of aeolid nudibranchia (Mollusca, Gastropoda, Opisthobranchia) with Symbiodinium. Symbiosis
    Vitenskapelig artikkel
  • Fossmark, Reidar; Johnsen, Geir; Waldum, Helge; Johannesen, Eli Marie. (2005) Rebound acid hypersecretion after long-term inhibition of gastric acid secretion. Alimentary Pharmacology and Therapeutics
    Vitenskapelig artikkel

2004

  • Hancke, Torunn Beate; Johnsen, Geir. (2004) SISCAL processor evaluation document. www.siscal.net
    Rapport
  • Chauton, Matilde Skogen; Tilstone, Gavin; Legrand, Catherine; Johnsen, Geir. (2004) Changes in pigmentation, bio-optical characteristics and photophysiology, during phytoflagellate succession in mesocosms. Journal of Plankton Research
    Vitenskapelig artikkel

2003

  • Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL prototype evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
    Vitenskapelig artikkel
  • Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL End User Requirement evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
    Vitenskapelig artikkel
  • Chauton, Matilde Skogen; Optun, Odd Inge; Bathen, F. T; Volent, Z.; Gribbestad, Ingrid S.; Johnsen, Geir. (2003) HR MAS 1H NMR spectroscopy analysis of whole cells of marine microalgae. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Figueroa, F. L.; Escassi, L.; Perez-Rodriguez, E.; Korbee, N.; Johnsen, Geir. (2003) Effects of the irradiance in the short-term on accumulation of mycosporine like amino acids in sun and shade species of the red algal genus Porphyra. Photochemistry and Photobiology
    Vitenskapelig artikkel

2002

  • Johansen, Torunn Beate; Johnsen, Geir. (2002) End User Requirements document. [Mangler utgivernavn]
    Rapport
  • Johansen, Torunn Beate; Johnsen, Geir. (2002) End User requirement evaluation document. [Mangler utgivernavn]
    Rapport
  • Gileptis, Laura; Johnsen, Geir; Moxness, Helge; Norwich, Inger; Vangen, Steffen. (2002) Modul for mønstergjenkjenning/klassifisering i DynamicImager ved bruk av backpropagation-algoritmen. Piksel'n : Organ for NOBIM (Norsk forening for bildebehandling og mønstergjenkjenning)
    Vitenskapelig artikkel
  • Millie, David; Schofield, Oscar; Kirkpatrick, Gary J.; Johnsen, Geir; Evens, Tim J.. (2002) Using absorbance and fluorescence spectra to discriminate microalgae. European journal of phycology
    Vitenskapelig artikkel
  • Johnsen, Geir; Børsheim, Knut Yngve; Johansen, Torunn Beate. (2002) Production and mortality of phytoplankton and sea-ice microalgae in the southern ocean. Rapportserie (Norsk polarinstitutt)
    Vitenskapelig artikkel

2001

  • Johnsen, Geir. (2001) SISCAL End User Requirement Satellite-based Information System on Coastal Areas and Lakes. Information Society Technologies Programme funded by the European Comm
    Rapport
  • Wägele, Heike; Johnsen, Geir. (2001) New results on histology and photosynthetic performance of solar-powered� opisthobranchs (Mollusca, Gastropoda, Opisthobranchia) containing symbiotic chloroplasts or zooxanthellae. Organisms Diversity & Evolution
    Vitenskapelig artikkel
  • Legrand, Catherine; Johnsen, Geir; Graneli, Edna; Sakshaug, Egil. (2001) (Proceedings of the 9th International conference on Harmful Algal Blooms. Hobart, Tasmania, 7-11 February 2000.) Effect of polyamines on growth and toxicity of Chrysochromulina leadbeateri, Haptophytae. Phycologia
    Vitenskapelig artikkel
  • Graneli, Edna; Legrand, Catherine; Carlsson, Per; Johnsen, Geir; Maestrini, Serge Y.; Reichelt, Michael. (2001) (Proceedings of the 9th International conference on Harmful Algal Blooms. Hobart, Tasmania, 7-11 February 20). Structuration of marine phytoplankton communities subjected to different levels of N, P and Si limitation in a mesocosm experiment (summary paper). Phycologia
    Vitenskapelig artikkel
  • Legrand, Catherine; Johansson, Niclas; Johnsen, Geir; Børsheim, Knut Yngve; Graneli, Edna. (2001) Phagotrophy and toxicity in the photosynthetic Prymnesium patelliferum (Haptophyte). Limnology and Oceanography
    Vitenskapelig artikkel

1998

  • Johnsen, Geir; Samset, O.; Sakshaug, Egil. (1998) Bio-optical classification of potential harmful chlorophyll c -containing prymnesiophyte blooms in Scandinavian water.
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Seppala, J; Johnsen, Geir; Babichenko, S; Leeben, A; Poryvkina, L; Shalapyonok, [Mangler fornavn]. (1998) In vivo light absorption by photosynthetic and photoprotective algal pigments: Methodology and the effects of light acclimation and nutrient limitation. Report Series in Geophysics
    Vitenskapelig artikkel
  • Johnsen, Geir; Dalløkken, Runar; Aure, J; Skjoldal, H. R. (1998) Photophysiology and environmental conditions during a toxic bloom of Chrysochromulina leadbeateri (Prymnesiophyceae). International symposium on Harmful Algal Blooms
    Vitenskapelig artikkel
  • Johnsen, Geir; Eikrem, W.; Dalløkken, R.; Aure, J.; Skjoldal, H. R.. (1998) Physiology and environmental conditions during a toxic blooms of Chrysochromulina leadbeateri Prymnesiophyceae. Journal of Phycology
    Vitenskapelig artikkel

1997

  • Johnsen, Geir; Volent, Z.; Tangen, K.; Sakshaug, Egil. (1997) Time series of harmful and benign phytoplankton blooms in northwest European waters using the Seawatch buoy system.
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Volent, Z.; Tangen, K.; Sakshaug, Egil. (1997) Time series of harmful and benign phytoplankton blooms in northwest European waters using the Seawatch buoy system.
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Grzymski, J.; Johnsen, Geir; Sakshaug, Egil. (1997) The significance of intracellular self-shadingon the bio-optical properties of brown, red and green macroalgal species. Journal of Phycology
    Vitenskapelig artikkel
  • Johnsen, Geir; Prezelin, B. B.; Jovine, R. V. M.. (1997) Fluorescence excitation spectra and light utiliation in two red tide dinoflagellates. Limnology and Oceanography
    Vitenskapelig artikkel
  • Millie, D.; Schofield, O. M.; Kirkpatrick, G. J.; Johnsen, Geir; Tester, P. A.; Vinyard, B. T.. (1997) Phytoplankton pigments and absorption spectra as potential bio-markers for harmful algal blooms: A case study of the Florida red-tide dinoflagellat Gymnodinium breve. Limnology and Oceanography
    Vitenskapelig artikkel
  • Grzymski, J.; Johnsen, Geir; Sakshaug, Egil. (1997) The significance of intracellular self-shading on the bio-optical properties of brown, red and green macroalgal species. Journal of Phycology
    Vitenskapelig artikkel

1996

  • Vernet, M.; Mitchell, B.G.; Sakshaug, Egil; Johnsen, Geir; Iturriaga, R.; Wassmann, P.. (1996) Evidence for a novel pigment with in vivo absorption maximum at 708 nm associated with Phaeocystis cf. pouchetii blooms. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Schofield, O.; Prezelin, B. B.; Johnsen, Geir. (1996) Wavelength-dependency of maximum quantum yield of carbon fixation for two red tide dinoflagellates, Heterocapsa pygmaea and prorocentrum minimum. Journal of Phycology
    Vitenskapelig artikkel
  • Johnsen, Geir; Sakshaug, Egil. (1996) Light harvesting in bloom-forming marine phytoplankton: Species-specifity and photoacclimation,. Scientia Marina
    Vitenskapelig artikkel
  • Johnsen, Geir; Volent, Z; Tangen, K; Sakshaug, Egil. (1996) Time-series of potential toxic phytoplankton blooms in North European waters in 1993 using the SEAWATCH-Europe buoy system. EOS
    Vitenskapelig artikkel
  • Vernet, M.; Mitchell, B. G.; Sakshaug, Egil; Johnsen, Geir; Iturriaga, R.; Wassmann, P.. (1996) Evidence for a novel pigment with in vivo absorption maximum at 708 nm associated with Phaeocystis sp. blooms. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Millie, D; Shofield, O. M; Kirkpatrick, G. J; Tester, P. A; Johnsen, Geir. (1996) Using bio-optical characterisics as bio-markers for harmful algal blooms: A case study of the Florida red-tide dinoflagellate,. EOS
    Vitenskapelig artikkel

1995

  • Johnsen, Geir; Sakshaug, Egil. (1995) Light harvesting in bloom-forming marine phytoplankton: species-specificity and photoadaption. Scientia Marina
    Vitenskapelig artikkel
  • Egeland, E.; Johnsen, Geir; Eikrem, W.; Liaaen-Jensen, S.; Throndsen, J.. (1995) The pigments of Bathycoccus prasinos. Journal of Phycology
    Vitenskapelig artikkel
  • Jovine, R. V.; Johnsen, Geir; Prezelin, B. B.. (1995) Isolation of membrane bound chlorophyll a-chlorofhyll c binding light harvesting complexes from the dinoflagellates heterocapsa pygmaea and Prorocentrum minimum. Photosynthesis Research
    Vitenskapelig artikkel

1994

  • Johnsen, Geir. (1994) Light Harvesting and Utiliation in Marine Phytoplankton: Species-Specific and Photoadaptive Responses. Dr. Scient. Thesis in Marine Botany, University of Trondheim
    Doktorgradsavhandling
  • Johnsen, Geir; Nelson, N. B.; Jovine, R. V. M.; Prezelin, B. B.. (1994) Chromoprotein- and pigment-dependent modeling of spectral light absorption in two dinoflagellates, Prorocentrum minimum and Heterocapsa pygmaea. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Jovine, R. V; Johnsen, Geir; Prezelin, B. B. (1994) Photoadaptation of Prorocentrum minimum and Heterocapsa pygmaea (Dinoflagellates): Chromoprotein changes and the consequenses for spectral absorption. EOS
    Vitenskapelig artikkel
  • Jovine, R. V.; Schofield, O.; Johnsen, Geir; Prezelin, B. B.. (1994) Photoacclimatory differences in the light-harvesting complex of the bloom forming dinoflagellates Heterocapsa pygmaea and Prorocentrum minimum. Journal of Phycology
    Vitenskapelig artikkel
  • Johnsen, Geir; Samset, O.; Granskog, L.; Sakshaug, Egil. (1994) In vivo absorption characteristics in 10 classes of phytoplankton: Taxonomic characteristics and responses to photoadaption by means of discriminant and HPLC analysis. Marine Ecology Progress Series
    Vitenskapelig artikkel

1993

  • Johnsen, Geir; Sakshaug, Egil. (1993) Bio-optical characteristics and photoadaptive responses in the toxic and bloomforming dinoflagellates Gyrodinium aureolum, Gymnodinium galatheanum two strains of Prorocentrum minium. Journal of Phycology
    Vitenskapelig artikkel
  • Gilstad, Mona; Johnsen, Geir; Sakshaug, Egil. (1993) Photosynthetic parameters, pigment composition and respiration rates of the marine diatom Skeletonema costatum grown in continuous light and a 12:1 light-dark cycle. Journal of Plankton Research
    Vitenskapelig artikkel
  • Volent, Zsolt; Johnsen, Geir. (1993) Presentation of an optical sensor-"OPTISENS" designed for Eulerian measurements of Phytoplankton on a buoy. Underwater light measurements. Proceedings from International Symposium on high latitude optics.
    Vitenskapelig artikkel

1992

  • Syvertsen, E.; Hegseth, E; Johnsen, Geir; Sakshaug, Egil; Gulliksen, B; Lønne, O. J. (1992) Livet i isen (The life in the ice). In Økosystem Barentshavet. [Mangler utgivernavn]
    Fagbok
  • Sakshaug, Egil; Kristiansen, S; Syvertsen, E; Eilertsen, H. C; Gilstad, M; Hegseth, E. N. (1992) Planktonalger (Phytoplankton). In Økosystem Barentshavet. [Mangler utgivernavn]
    Fagbok
  • Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1992) Bio-optical characteristicts of phytoplankton in relation to remote sensing. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
    Vitenskapelig artikkel
  • Volent, Zsolt; Johnsen, Geir. (1992) Presentation of an optical sensor-"OPTISENS" designed for Eulerian measurements of Phytoplankton on a moored buoy. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
    Vitenskapelig artikkel
  • Johnsen, Geir; Sakshaug, Egil; Vernet, Maria. (1992) Pigment composition, spectral characteriation and photosynthetic parameters in Chrysochromulina polylepis. Marine Ecology Progress Series
    Vitenskapelig artikkel

1991

  • Johnsen, Geir. (1991) Proceedings from a scientific working meeting. Fisken og Havet
    Vitenskapelig artikkel
  • Johnsen, Geir; Hegseth, Else Nøst. (1991) Photoadaptation of sea-ice microalgae in the Barents Sea. Polar Biology
    Vitenskapelig artikkel
  • Johnsen, Geir. (1991) Identification of Chrysochromulina leadbeateri by means of remote sensing. Fisken og Havet
    Vitenskapelig artikkel
  • Sakshaug, Egil; Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1991) Identification of phytoplankton blooms by means of remote sensing. Environment Northern Seas
    Vitenskapelig artikkel
  • Sakshaug, Egil; Johnsen, Geir; Andresen, Kjersti; Vernet, Maria. (1991) Modeling of light-dependent algal photosynthesis and growth: Experiments with the Barents Sea diatoms Thalassiosira nordensskioeldii and Chaetocero furcellatus. Deep-Sea Research Part II: Topical Studies in Oceanography
    Vitenskapelig artikkel

Tidsskriftspublikasjoner

  • Williamson, David Roddan; Moreira Fragoso, Glaucia; Majaneva, Sanna Kristiina; Dallolio, Alberto; Halvorsen, Daniel Ørnes; Hasler, Oliver Kevin. (2023) Monitoring Algal Blooms with Complementary Sensors on Multiple Spatial and Temporal Scales. Oceanography
    Vitenskapelig artikkel
  • Bakken, Sivert; Henriksen, Marie Bøe; Birkeland, Roger; Langer, Dennis David; Oudijk, Adriënne Esmeralda; Berg, Simen. (2023) HYPSO-1 CubeSat: First Images and In-Orbit Characterization. Remote Sensing
    Vitenskapelig artikkel
  • Summers, Natalie Maria; Moreira Fragoso, Glaucia; Johnsen, Geir. (2023) Photophysiologically active green, red, and brown macroalgae living in the Arctic Polar Night. Scientific Reports
    Vitenskapelig artikkel
  • Grant, Stephen Denis; Johnsen, Geir; McKee, David; Zolich, Artur Piotr; Cohen, Jonathan H.. (2023) Spectral and RGB analysis of the light climate and its ecological impacts using an all-sky camera system in the Arctic. Applied Optics
    Vitenskapelig artikkel
  • Gerland, Sebastian; Ingvaldsen, Randi Brunvær; Reigstad, Marit; Sundfjord, Arild; Bogstad, Bjarte; Chierici, Melissa. (2023) Still Arctic? — The changing Barents Sea. Elementa: Science of the Anthropocene
    Vitenskapelig oversiktsartikkel/review
  • Schartmuller, Bernhard; Anderson, Philip; Mckee, David; Connan-McGinty, Stacey; Kopec, Tomasz Piotr; Daase, Malin Hildegard Elisabeth. (2023) Development and calibration of a high dynamic range and autonomous ocean-light instrument to measure sub-surface profiles in ice-covered waters. Applied Optics
    Vitenskapelig artikkel
  • Summers, Natalie; Johnsen, Geir; Mogstad, Aksel Alstad; Løvås, Håvard; Fragoso, Glaucia Moreira; Berge, Jørgen. (2022) Underwater Hyperspectral Imaging of Arctic Macroalgal Habitats during the Polar Night Using a Novel Mini-ROV-UHI Portable System. Remote Sensing
    Vitenskapelig artikkel
  • Fragoso, Glaucia Moreira; Davies, Emlyn John; Fossum, Trygve Olav; Ullgren, Jenny; Majaneva, Sanna; Aberle-Malzahn, Nicole. (2022) Contrasting phytoplankton-zooplankton distributions observed through autonomous platforms, in-situ optical sensors and discrete sampling. PLOS ONE
    Vitenskapelig artikkel
  • Mogstad, Aksel Alstad; Løvås, Håvard; Sture, Øystein; Johnsen, Geir; Ludvigsen, Martin. (2022) Remote Sensing of the Tautra Ridge: An Overview of the World’s Shallowest Cold-Water Coral Reefs. Frontiers in Marine Science
    Vitenskapelig artikkel
  • Connan-McGinty, Stacey; Banas, Neil S.; Berge, Jørgen; Cottier, Finlo Robert; Grant, Stephen; Johnsen, Geir. (2022) Midnight Sun to Polar Night: A Model of Seasonal Light in the Barents Sea. Journal of Advances in Modeling Earth Systems
    Vitenskapelig artikkel
  • Oudijk, Esmée; Hasler, Oliver Kevin; Øveraas, Henning; Marty, Sabine; Williamson, David Roddan; Svendsen, Torbjørn Karl. (2022) Campaign For Hyperspectral Data Validation In North Atlantic Coastal Waters. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
    Vitenskapelig artikkel
  • Dona, Angela; Evertsen, Jussi; Johnsen, Geir. (2022) The role of parapodia and lack of photoacclimation in kleptoplasts of the sacoglossan sea slug Plakobranchus ocellatus. Coral reefs
    Vitenskapelig artikkel
  • Cohen, Jonathan H.; Last, Kim; Charpentier, Corie L.; Cottier, Finlo; Daase, Malin; Hobbs, Laura. (2021) Photophysiological cycles in Arctic krill are entrained by weak midday twilight during the Polar Night. PLoS Biology
    Vitenskapelig artikkel
  • Cardwell, CR; Berge, Jørgen; Johnsen, Geir. (2021) Arctic voyage shines light on some cold, hard truths. The Herald, UK
    Populærvitenskapelig artikkel
  • Bazilchuk, Nancy Reney; Berge, Jørgen; Johnsen, Geir. (2021) Lysforurensning I Arktis kan ha ødelagt forskningsresultater. Gemini.no
    Populærvitenskapelig artikkel
  • Ringvold, Halldis; Taite, Morag; Allcock, A. Louise; Vecchione, Michael; Péan, Michel; Sandulli, Roberto. (2021) In situ recordings of large gelatinous spheres from NE Atlantic, and the first genetic confirmation of egg mass of Illex coindetii (Vérany, 1839) (Cephalopoda, Mollusca). Scientific Reports
    Vitenskapelig artikkel
  • Bakken, Sivert; Johnsen, Geir; Johansen, Tor Arne. (2021) Analysis and Model Development of Direct Hyperspectral Chlorophyll-A Estimation for Remote Sensing Satellites. Workshop on Hyperspectral Image and Signal Processing, Evolution in Remote Sensing
    Vitenskapelig artikkel
  • Horni, K; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin. (2021) Internasjonalt forskningsmiljø dykker i Mjøsa etter at Oppland Arbeiderblad skrev om forurensning. Oppland arbeiderblad
    Populærvitenskapelig artikkel
  • Bazilchuk, Nancy Reney; Stahl, Annette; Johnsen, Geir; Saad, Aya; Thu, Maren; Nøland, Annecken. (2021) Sporhunden som lukter mikroalger. . Gemini.no
    Populærvitenskapelig artikkel
  • Johnsen, Geir; Zolich, Artur; Grant, Stephen; Bjørgum, Rune; Cohen, Jonathan H.; Mckee, David. (2021) All-sky camera system providing high temporal resolution annual time series of irradiance in the arctic. Applied Optics
    Vitenskapelig artikkel
  • Geoffroy, Maxime; Langbehn, Tom Jasper; Priou, Pierre; Varpe, Øystein; Johnsen, Geir; Le Bris, Arnault. (2021) Pelagic organisms avoid white, blue, and red artificial light from scientific instruments. Scientific Reports
    Vitenskapelig artikkel
  • Løvås, Håvard; Mogstad, Aksel Alstad; Sørensen, Asgeir Johan; Johnsen, Geir. (2021) A Methodology for Consistent Georegistration in Underwater Hyperspectral Imaging. IEEE Journal of Oceanic Engineering
    Vitenskapelig artikkel
  • Faltynkova, Andrea; Johnsen, Geir; Wagner, Martin. (2021) Hyperspectral imaging as an emerging tool to analyze microplastics: A systematic review and recommendations for future development. Microplastics and Nanoplastics
    Vitenskapelig oversiktsartikkel/review
  • Ramirez-Llodra, Eva; Hilário, Ana; Paulsen, Emil; Costa, Carolina; Bakken, Torkild; Johnsen, Geir. (2020) Benthic Communities on the Mohn’s Treasure Mound: Implications for Management of Seabed Mining in the Arctic Mid-Ocean Ridge. Frontiers in Marine Science
    Vitenskapelig artikkel
  • Gibbens, Sarah; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2020) As the Arctic warms, light pollution may pose a new treat to marine life. . National Geographic
    Intervju tidsskrift
  • Berge, Jørgen; Geoffroy, Maxime; Daase, Malin; Cottier, Finlo Robert; Priou, Pierre; Cohen, Jonathan H.. (2020) Artificial light during the polar night disrupts Arctic fish and zooplankton behavior down to 200 m depth. Communications Biology
    Vitenskapelig artikkel
  • Saad, Aya; Stahl, Annette; Våge, Andreas; Davies, Emlyn John; Nordam, Tor; Aberle-Malzahn, Nicole. (2020) Advancing Ocean Observation with an AI-driven Mobile Robotic Explorer. Oceanography
    Vitenskapelig artikkel
  • Fragoso, Glaucia Moreira; Johnsen, Geir; Chauton, Matilde Skogen; Cottier, Finlo Robert; Ellingsen, Ingrid H.. (2020) Phytoplankton community succession and dynamics using optical approaches. Continental Shelf Research
    Vitenskapelig artikkel
  • Mogstad, Aksel Alstad; Ødegård, Øyvind; Nornes, Stein Melvær; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan. (2020) Mapping the Historical Shipwreck Figaro in the High Arctic Using Underwater Sensor-Carrying Robots. Remote Sensing
    Vitenskapelig artikkel
  • Fragoso, Glaucia Moreira; Davies, Emlyn John; Ellingsen, Ingrid H.; Chauton, Matilde Skogen; Fossum, Trygve Olav; Ludvigsen, Martin. (2019) Physical controls on phytoplankton size structure, photophysiology and suspended particles in a Norwegian biological hotspot. Progress in Oceanography
    Vitenskapelig artikkel
  • Kleiven, Wanda; Johnsen, Geir; Ardelan, Murat Van. (2019) Sea surface microlayer and elemental composition in phaeo-, chloro-, and rhodophytes in winter and spring. Journal of Phycology
    Vitenskapelig artikkel
  • Mogstad, Aksel Alstad; Johnsen, Geir; Ludvigsen, Martin. (2019) Shallow-Water Habitat Mapping using Underwater Hyperspectral Imaging from an Unmanned Surface Vehicle: A Pilot Study. Remote Sensing
    Vitenskapelig artikkel
  • Kauko, Hanna Maria; Pavlov, Alexey; Johnsen, Geir; Granskog, Mats; Peeken, Ilka; Assmy, Philipp. (2019) Photoacclimation state of an Arctic underice phytoplankton bloom. Journal of Geophysical Research (JGR): Oceans
    Vitenskapelig artikkel
  • Bazilchuk, Nancy Reney; Fossum, Trygve Olav; Fragoso, Glaucia Moreira; Ludvigsen, Martin; Johnsen, Geir. (2019) Smart undervannsrobot leter etter plankton. Av N Bazilchuk. Forskning.no. Angående NTNU Entice prosjekt publisert i Science Robotics. Forskning.no
    Populærvitenskapelig artikkel
  • Fossum, Trygve Olav; Fragoso, Glaucia Moreira; Davies, Emlyn John; Ullgren, Jenny; Mendes, Renato; Johnsen, Geir. (2019) Toward adaptive robotic sampling of phytoplankton in the coastal ocean. Science robotics
    Vitenskapelig artikkel
  • Fragoso, Glaucia Moreira; Poulton, Alex James; Pratt, Nicola Jane; Johnsen, Geir; Purdie, Duncan Alastair. (2019) Trait-based analysis of subpolar North Atlantic phytoplankton and plastidic ciliate communities using automated flow cytometer. Limnology and Oceanography
    Vitenskapelig artikkel
  • Fragoso, Glaucia Moreira; Poulton, Alex J.; Yashayaev, Igor M.; Head, Erica J.H.; Johnsen, Geir; Purdie, Duncan A.. (2018) Diatom biogeography from the Labrador Sea revealed through a trait-based approach. Frontiers in Marine Science
    Vitenskapelig artikkel
  • Dumke, Ines; Nornes, Stein Melvær; Purser, Autun; Marcon, Yann; Ludvigsen, Martin; Ellefmo, Steinar Løve. (2018) First hyperspectral imaging survey of the deep seafloor: High-resolution mapping of manganese nodules. Remote Sensing of Environment
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning - enda en kilde til bekymring. Svalbardposten
    Kronikk
  • Berge, Jørgen; Johnsen, Geir. (2018) Lysforurensning truer livet i Arktis. Aftenposten Viten
    Kronikk
  • Ludvigsen, Martin; Berge, Jørgen; Geoffroy, Maxime; Cohen, Jonathan H.; De La Torre, Pedro R.; Nornes, Stein Melvær. (2018) Use of an autonomous surface vehicle reveals small-scale diel vertical migrations of zooplankton and susceptibility to light pollution under low solar irradiance. Science Advances
    Vitenskapelig artikkel
  • Ødegård, Øyvind; Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging: a new tool for marine archaeology. Applied Optics
    Vitenskapelig artikkel
  • Fossum, Trygve Olav; Eidsvik, Jo; Ellingsen, Ingrid H.; Alver, Morten; Fragoso, Glaucia Moreira; Johnsen, Geir. (2018) Information-driven robotic sampling in the coastal ocean. Journal of Field Robotics (JFR)
    Vitenskapelig artikkel
  • Kauko, Hanna Maria; Olsen, Lasse Mork; Duarte, Pedro; Peeken, Ilka; Granskog, Mats A.; Johnsen, Geir. (2018) Algal colonization of young arctic sea ice in spring. Frontiers in Marine Science
    Vitenskapelig artikkel
  • Dumke, Ines; Purser, Autun; Marcon, Yann; Nornes, Stein Melvær; Johnsen, Geir; Ludvigsen, Martin. (2018) Underwater hyperspectral imaging as an in situ taxonomic tool for deep-sea megafauna. Scientific Reports
    Vitenskapelig artikkel
  • Liefmann, Stephanie; Järnegren, Johanna; Johnsen, Geir; Murray, Fiona. (2018) Eco-physiological responses of cold-water soft corals to anthropogenic sedimentation and particle shape. Journal of Experimental Marine Biology and Ecology
    Vitenskapelig artikkel
  • Geoffroy, Maxime; Berge, Jørgen; Majaneva, Sanna Kristiina; Johnsen, Geir; Langbehn, Tom; Cottier, Finlo Robert. (2018) Increased occurrence of the jellyfish Periphylla periphylla in the European high Arctic. Polar Biology
    Short communication
  • Johnsen, Geir; Norli, Marit; Moline, Mark A.; Robbins, Ian; Quillfeldt, Cecilie von; Sørensen, Kai. (2018) The advective origin of an under-ice spring bloom in the Arctic Ocean using multiple observational platforms. Polar Biology
    Vitenskapelig artikkel
  • Dumke, Ines; Ludvigsen, Martin; Ellefmo, Steinar Løve; Søreide, Fredrik; Johnsen, Geir; Murton, Bramley J.. (2018) Underwater Hyperspectral Imaging Using a Stationary Platform in the Trans-Atlantic Geotraverse Hydrothermal Field. IEEE Transactions on Geoscience and Remote Sensing
    Vitenskapelig artikkel
  • Gabrielsen, Tove M.; Johnsen, Geir. (2018) Skogen på Svalbard. Svalbardposten
    Populærvitenskapelig artikkel
  • Otterlei, Inger; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin; Hareide, Nils Roar; Christensen-Dalsgaard, Signe. (2017) 300 000 sjøfugl er forsvunnet fra Runde. Sunnmørsposten
    Intervju tidsskrift
  • Johnsen, Geir; Christiansen, Hanne H; Ravolainen, Virve; Reymert, Per Kyrre; Jenssen, Eva Therese; Arlov, Thor Bjørn. (2017) Utfordrende natur og sikkerhet på Svalbard. Svalbardposten
    Kronikk
  • Ostaszewska, Kaja; Balazy, Piotr; Berge, Jørgen; Johnsen, Geir; Staven, Robert. (2017) Seabirds during Arctic Polar Night: underwater observations from Svalbard archipelago, Norway. Waterbirds (De Leon Springs, Fla.)
    Vitenskapelig artikkel
  • Kauko, Hanna Maria; Taskjelle, Torbjørn; Assmy, Philipp; Pavlov, Alexey K.; Mundy, C.J.; Duarte, Pedro. (2017) Windows in Arctic sea ice: light transmission and ice algae in a refrozen lead. Journal of Geophysical Research (JGR): Biogeosciences
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir. (2017) Kunnskapshull om livet i Arktis i mørketiden. Aftenposten Viten
    Kronikk
  • Assmy, Philipp; Fernández-Méndez, Mar; Duarte, Pedro; Meyer, Amelie; Randelhoff, Achim; Mundy, Christopher John. (2017) Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ic. Scientific Reports
    Vitenskapelig artikkel
  • Mogstad, Aksel Alstad; Johnsen, Geir. (2017) Spectral characteristics of coralline algae: a multi-instrumental approach, with emphasis on underwater hyperspectral imaging. Applied Optics
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir. (2017) Om bambus, spøkelseskreps og et Arktis i endring. Svalbardposten
    Kronikk
  • Berge, Jørgen; Johnsen, Geir. (2017) Superkommunisten. Svalbardposten
    Kronikk
  • Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) Opp fra polarnattens mørke. Aftenposten Viten
    Kronikk
  • Berge, Jørgen; Ødegård, Øyvind; Johnsen, Geir. (2016) A bitter-sweet symphony. Svalbardposten
    Kronikk
  • Berge, Jørgen; Geoffroy, Maxime; Johnsen, Geir; Cottier, Finlo Robert; Bluhm, Bodil; Vogedes, Daniel Ludwig. (2016) Ice-tethered observational platforms in the Arctic Ocean pack ice. IFAC-PapersOnLine
    Vitenskapelig artikkel
  • Cronin, Heather; Cohen, Jonathan H.; Berge, Jørgen; Johnsen, Geir; Moline, Mark A.. (2016) Bioluminescence as an ecological factor during high Arctic polar night. Scientific Reports
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Ludvigsen, Martin; Cohen, Jonathan. (2016) Design for latskap - men med store muligheter. Svalbardposten
    Kronikk
  • Bondø, Tor-Hartvig; Johnsen, Geir; Berge, Jørgen. (2016) Fant yrende liv i polarnatta. VG : Verdens gang
    Populærvitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir. (2016) Mørkets fyrster med påskrudd lys. Svalbardposten
    Populærvitenskapelig artikkel
  • Bazilchuk, Nancy Reney; Leite, Stein Roar; Johnsen, Geir; Kjeken, John; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2016) Bomber og buss på havbunnen. Gemini
    Populærvitenskapelig artikkel
  • Haudemann-Andersen, Jørn; Lystad, M S; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen. (2016) Blå lys i det kalde dyp. NRK Trøndelag, Nyheter
    Populærvitenskapelig artikkel
  • Haugstad, Tor; Erdal, Ivar; Johnsen, Geir; Sørensen, Asgeir Johan; Fjærvik, Nils. (2016) Gründerne mener dette kameraet kan bli det nye ekkoloddet – Ecotone er kandidat til TU Tech Award. Teknisk Ukeblad
    Populærvitenskapelig artikkel
  • Bjørgan, Espen Halvorsen; Johnsen, Geir; Kjeken, Jon; Ludvigsen, Martin. (2016) Fant buss på 600 m dybde. Adresseavisen
    Populærvitenskapelig artikkel
  • Johnsen, Geir; Ludvigsen, Martin; Sørensen, Asgeir Johan; Aas, Lars Martin Sandvik. (2016) The use of underwater hyperspectral imaging deployed on remotely operated vehicle – methods and applications. IFAC-PapersOnLine
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Kinderegg i polarnatten. Svalbardposten
    Kronikk
  • Donahue, Michelle; Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) The age of humans - living in the anthropocene - "Termites of the sea" found munching wood near Arctic shipwrecks. Smithsonian
    Populærvitenskapelig artikkel
  • Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Dark lords, werewolves and Indiana Jones in the polar night. Gemini (English edition)
    Intervju tidsskrift
  • Krüger, Frida Jørstad; Johnsen, Geir; Kjeken, John; Ludvigsen, Martin. (2016) Gammel buss ble korallrev. NRK Viten
    Populærvitenskapelig artikkel
  • Kokkegård, Hanne; Johnsen, Geir; Ludvigsen, Martin; Torre, Pedro De La. (2016) Vitenskab - Bomber fra 2 verdenskrig danner koralrev på 600 m dybde. Danmarks radio
    Populærvitenskapelig artikkel
  • Haugstad, Tormod; Erdal, Ivar; Johnsen, Geir. (2016) Kameraet deres «kan bli det nye ekkoloddet». Nå er det norske selskapet i ferd med å lykkes. Teknisk Ukeblad
    Intervju tidsskrift
  • Johnsen, Geir. (2016) Yrende liv i Isfjorden. Svalbardposten
    Populærvitenskapelig artikkel
  • Aarskog, Karine Nigar; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2016) Et stort løft for arktisk forskning (NTNU & UiT). Universitetet i Tromsø
    Fagartikkel
  • Berge, Jørgen; Falk-Petersen, Stig; Renaud, Paul E.; Daase, Malin; Geoffroy, Maxime; Johnsen, Geir. (2016) En reise mot Ultima Thule. Svalbardposten
    Populærvitenskapelig artikkel
  • Lervik, Frank; Johnsen, Geir; Ludvigsen, Martin; Kjeken, John. (2016) Det ligger flere busser der. Adresseavisen
    Populærvitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Ødegård, Øyvind. (2016) Mark spiser opp vrak på havbunnen. Fiskaren
    Populærvitenskapelig artikkel
  • Kintisch, Eli; Berge, Jørgen; Last, Kim; Cohen, Jonathan; Johnsen, Geir. (2016) Voyage into darkness . Science
    Intervju tidsskrift
  • Bazilchuk, Nancy Reney; Johnsen, Geir; Berge, Jørgen; Ludvigsen, Martin; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2016) Mørkets fyrster, varulver og Indiana Jones. Gemini
    Populærvitenskapelig artikkel
  • Berge, Jørgen; Renaud, Paul E.; Johnsen, Geir; Darnis, Gerald; Geoffroy, Maxime; Daase, Malin. (2016) I grenselandet (mellom Tull og Thule). Svalbardposten
    Populærvitenskapelig artikkel
  • Førde, Henny; Forbord, Silje; Handå, Aleksander; Fossberg, Julia; Arff, Johanne; Johnsen, Geir. (2016) Development of bryozoan fouling on cultivated kelp (Saccharina latissima) in Norway. Journal of Applied Phycology
    Vitenskapelig artikkel
  • Nilssen, Ingunn; Dos Santos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral, Marcelo M.; Eide, Ingvar. (2015) Assessing the potential impact of water-based drill cuttings on deep water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
    Vitenskapelig artikkel
  • Nilssen, Ingunn; Santos dos, Francisco; Coutinho, Ricardo; Gomes, Natalia; Cabral Montenegro, Marcelo; Eide, Ingvar. (2015) Assessing the potential impact of water-based drill cuttings on deep-water calcareous red algae using species specific impact categories and measured oceanographic and discharge data. Marine Environmental Research
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan; Nilssen, Ingunn. (2015) Enabling technology for Arctic research. Pan European Networks: Science and Techology Magazine
    Vitenskapelig oversiktsartikkel/review
  • Rodriguez, Francisco; Garrido, J.L.; Sabrino, C; Johnsen, Geir; Riobo, P; Franco, J. (2015) Divinyl chlorophyll a in the marine eukaryotic protist Alexandrium ostenfeldii (Dinophyceae). Environmental Microbiology
    Vitenskapelig artikkel
  • Nilssen, Ingunn; Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Moline, Mark A.; Berge, Jørgen. (2015) Integrated environmental mapping and monitoring, a methodological approach to optimise knowledge gathering and sampling strategy. Marine Pollution Bulletin
    Vitenskapelig artikkel
  • Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Sørensen, Asgeir Johan; Last, Kim; Falk-Petersen, Stig. (2015) Is ambient light during the high Arctic polar night sufficient to act as a visual cue for zooplankton?. PLOS ONE
    Vitenskapelig artikkel
  • Berge, Jørgen; Renaud, Paul; Darnis, Gérald; Cottier, Finlo; Last, Kim; Gabrielsen, Tove M.. (2015) In the dark: a review of ecosystem processes during the Arctic polar night. Progress in Oceanography
    Vitenskapelig artikkel
  • Berge, Jørgen; Daase, Malin; Renaud, Paul; Ambrose, William G. Jr.; Darnis, Gérald; Last, Kim S. (2015) Unexpected levels of biological activity during the polar night offer new perspectives on a warming Arctic. Current Biology
    Vitenskapelig artikkel
  • Pettersen, Ragnhild; Johnsen, Geir; Bruheim, Per; Andreassen, Trygve. (2014) Development of hyperspectral imaging as a bio-optical taxonomic tool for pigmented marine organisms. Organisms Diversity & Evolution
    Vitenskapelig artikkel
  • Valle, Kristin Collier; Nymark, Marianne; Aamot, Inga; Hancke, Kasper; Winge, Per; Andresen, Kjersti. (2014) System responses to equal doses of photosynthetically usable radiation of blue, green, and red light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
    Vitenskapelig artikkel
  • Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Lågstad, Petter Arthur; Ødegård, Øyvind. (2014) Scientific Operations Combining ROV and AUV in the Trondheim Fjord. Marine Technology Society journal
    Vitenskapelig artikkel
  • Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Glowing in the dark: Discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
    Vitenskapelig artikkel
  • Hansen, Ingrid; Pettersen, Ragnhild; Beuchel, Frank; Cochrane, Sabine; Frantzen, marianne; Ekehaug, Stefan. (2014) Underwater hyperspectral imaging (UHI) for environmental mapping and monitoring of seabed habitats. Ocean Optics
    Sammendrag/abstract
  • Cohen, Jonathan; Cronin, Heather; Moline, Mark A.; Berge, Jørgen; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Are krill eyes useful in the high Arctic polar night?. Ocean Optics
    Sammendrag/abstract
  • Johnsen, Geir; Ekehaug, Stefan; Hansen, Ingrid; Sørensen, Asgeir Johan. (2014) The use of underwater hyperspectral imaging deployed on remotely operated vehicles to identify, map and monitor bio-geo-chemical objects of interest. Ocean Optics
    Sammendrag/abstract
  • Aamot, Inga; Pokrzywinski, Kaytee; Johnsen, Geir; Berge, Jørgen; Sørensen, Asgeir Johan. (2014) Light Climate and Status of the Photosynthetic Machinery in Macroalgae in the Polar Night. Ocean Optics
    Sammendrag/abstract
  • Nornes, Stein Melvær; Candeloro, Mauro; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan. (2014) Photomosaic camera as simultaneous data collector and navigation aid on unmanned underwater vehicles. Ocean Optics
    Sammendrag/abstract
  • Nilssen, Ingunn; Ødegård, Øyvind; Johnsen, Geir; Sørensen, Asgeir Johan; Berge, Jørgen; Nornes, Stein Melvær. (2014) Integrated environmental monitoring; a methodological approach to optimise knowledge gathering and sampling strategy. Ocean Optics
    Sammendrag/abstract
  • Johnsen, Geir; Candeloro, Mauro; Berge, Jørgen; Moline, Mark A.. (2014) Erratum to: Glowing in the dark: discriminating patterns of bioluminescence from different taxa during the Arctic polar night. Polar Biology
    Errata
  • Berge, Jørgen; Cottier, Finlo; Varpe, Øystein; Renaud, Paul; Falk-Petersen, Stig; Kwasniewski, Sawomir. (2014) Arctic complexity: A case study on diel vertical migration of zooplankton. Journal of Plankton Research
    Vitenskapelig artikkel
  • Hancke, Kasper; Hovland, Erlend Kjeldsberg; Volent, Zsolt; Pettersen, Ragnhild; Johnsen, Geir; Moline, Mark A.. (2014) Optical properties of CDOM across the Polar Front in the Barents Sea: Origin, distribution and significance. Journal of Marine Systems
    Vitenskapelig artikkel
  • Hovland, Erlend Kjeldsberg; Hancke, Kasper; Alver, Morten; Drinkwater, Kennneth F.; Høkedal, Jo; Johnsen, Geir. (2014) Optical impact of an Emiliania huxleyi bloom in the frontal region of the Barents Sea. Journal of Marine Systems
    Vitenskapelig artikkel
  • Båtnes, Anna Solvang; Miljeteig, Cecilie; Berge, Jørgen; Greenacre, Michael; Johnsen, Geir. (2013) Quantifying the light sensitivity of Calanus spp. during the polar night: potential for orchestrated migrations conducted by ambient light from the sun, moon, or aurora borealis. Polar Biology
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Falk-Pettersen, Stig. (2013) Mørkets hemmeligheter. Svalbardposten
    Populærvitenskapelig artikkel
  • Nymark, Marianne; Valle, Kristin Collier; Hancke, Kasper; Winge, Per; Andresen, Kjersti; Johnsen, Geir. (2013) Molecular and photosynthetic responses to prolonged darkness and subsequent acclimation to re-illumination in the diatom Phaeodactylum tricornutum. PLOS ONE
    Vitenskapelig artikkel
  • Hovland, Erlend Kjeldsberg; Dierssen, Heidi; Ferreira, Ana Sofia; Johnsen, Geir. (2013) Dynamics regulating major trends in Barents Sea temperatures and subsequent effect on remotely sensed particulate inorganic carbon. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Berge, Jørgen; Båtnes, Anna Solvang; Johnsen, Geir; Blackwell, Susan; Moline, Mark A.. (2012) Bioluminescence in the high Arctic during the polar night. Marine Biology
    Vitenskapelig artikkel
  • Gabrielsen, Tove M; Quillfeldt, Cecilie von; Johnsen, Geir; Berge, Jørgen. (2012) Varm vinter, sen vår i fjorden. Svalbardposten
    Leserinnlegg
  • Elde, Anette; Pettersen, Ragnhild; Bruheim, Per; Järnegren, Johanna; Johnsen, Geir. (2012) Pigmentation and Spectral Absorbance Signatures in Deep-Water Corals from the Trondheimsfjord, Norway. Marine Drugs
    Vitenskapelig artikkel
  • Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2011) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
    Vitenskapelig artikkel
  • Volent, Zsolt; Johnsen, Geir; Hovland, Erlend Kjeldsberg; Folkestad, Are; Olsen, Lasse Mork; Tangen, Karl. (2011) Improved monitoring of phytoplankton bloom dynamics in a Norwegian fjord by integrating satellite data, pigment analysis, and Ferrybox data with a coastal observation network. Journal of Applied Remote Sensing
    Vitenskapelig artikkel
  • Jouenne, Fabien; Eikrem, Wenche; Le Gall, F; Marie, Dominique; Johnsen, Geir; Vaulot, Daniel. (2011) Prasinoderma singularis sp. nov. (Prasinophyceae, Chlorophyta), a Solitary Coccoid Prasinophyte from the South-East Pacific Ocean. Protist
    Vitenskapelig artikkel
  • Pettersen, Ragnhild; Johnsen, Geir; Berge, Jørgen; Hovland, Erlend Kjeldsberg. (2011) Phytoplankton chemotaxonomy in waters around the Svalbard archipelago reveals high amounts of Chl b and presence of gyroxanthin-diester. Polar Biology
    Vitenskapelig artikkel
  • Thoen, Hanne Halkinrud; Johnsen, Geir; Berge, Jørgen. (2010) Pigmentation and spectral absorbance in the deep-sea arctic amphipods Eurythenes gryllus and Anonyx sp. Polar Biology
    Vitenskapelig artikkel
  • Aamot, Inga; Berge, Jørgen; Hancke, Kasper; Johnsen, Geir; Moline, Mark; Schofield, Oscar. (2010) NORUS - Technology Development for Marine Monitoring and Ocean Observation:An North America-Norway educational program. http://ipy-osc.no/abstract/
    Sammendrag/abstract
  • Johnsen, Geir; Søreide, Fredrik. (2010) Underwater hyperspectral imaging of marine mineral deposits. Underwater Mining meeting Institute (UMI)
    Sammendrag/abstract
  • Berge, Jørgen; Cottier, Finlo; Last, Kim S.; Varpe, Øystein; Leu, Eva; Søreide, Janne. (2009) Diel vertical migration of Arctic zooplankton during the polar night. Biology Letters
    Vitenskapelig artikkel
  • Nymark, Marianne; Valle, Kristin Collier; Brembu, Tore; Winge, Per; Hancke, Kasper; Andresen, Kjersti. (2009) An integrated analysis of molecular acclimation to high light in the marine diatom Phaeodactylum tricornutum. PLOS ONE
    Vitenskapelig artikkel
  • Berge, Jørgen; Lønne, Ole Jørgen; Renaud, Paul; Johnsen, Geir; Gulliksen, Bjørn; Varpe, Øystein. (2009) Polartorsken - vil den bli utkonkurrert av sørlige fiskearter?. Svalbardposten
    Populærvitenskapelig artikkel
  • Evertsen, Jussi; Johnsen, Geir. (2009) In vivo and in vitro differences in chloroplast functionality in the two north Atlantic sacoglossans (Gastropoda, Opisthobranchia) Placida dendritica and Elysia viridis. Marine Biology
    Vitenskapelig artikkel
  • Volent, Z; Johnsen, Geir; Sigernes, Fred. (2009) Microscopic hyperspectral imaging used as a bio-optical taxonomic tool for micro- and macroalgae. Applied Optics
    Vitenskapelig artikkel
  • Hancke, Torunn Beate; Hancke, Kasper; Johnsen, Geir; Sakshaug, Egil. (2008) Rate of O2 production derived from pulse-amplitude-modulated fluorescence: Testing three biooptical approaches against measured O2-production rate. Journal of Phycology
    Vitenskapelig artikkel
  • Bredholt, Harald; Fjærvik, Espen; Johnsen, Geir; Zotchev, Sergey. (2008) Actinomycetes from sediments in the Trondheim Fjord, Norway: Diversity and biological activity. Marine Drugs
    Vitenskapelig artikkel
  • Bakken, Torkild; Evertsen, Jussi; Johnsen, Geir. (2008) Vitenskapelig dykking - behov for endringer i forskriften. Dykkenytt : informasjonsorgan for dykkeindustrien
    Fagartikkel
  • Hancke, Kasper; Hancke, Torunn Beate; Olsen, Lasse Mork; Johnsen, Geir; Glud, RN. (2008) Temperature effects on microalgal photosynthesis-light responses measured by O2 production, pulse-amplitude-modulated fluorescence, and C-14 assimilation. Journal of Phycology
    Vitenskapelig artikkel
  • Hovland, Erlend Kjeldsberg; Johnsen, Geir; Moline, Mark. (2008) Combined use of AUV and hyperspectral imaging to mapping sea-surface and macroalgae. Ocean Optics
    Sammendrag/abstract
  • Cibic, Tamara; Blasutto, Oriana; Hancke, Kasper; Johnsen, Geir. (2007) Microphytobenthic species composition, pigment concentration, and primary production in sublittoral sediments of the Trondheimsfjord (Norway). Journal of Phycology
    Vitenskapelig artikkel
  • Evertsen, Jussi; Burghardt, Ingo; Johnsen, Geir; Wägele, Heike. (2007) Retention of functional chloroplasts in some sacoglossans from the Indo-Pacific and Mediterranean. Marine Biology
    Vitenskapelig artikkel
  • Ludvigsen, Martin; Sortland, Bjørn; Johnsen, Geir; Singh, Hanumant. (2007) Applications of Geo-Referenced Underwater Photo Mosaics in Marine Biology and Archaeology. Oceanography
    Vitenskapelig artikkel
  • Johnsen, Geir; Sakshaug, Egil. (2007) Biooptical characteristics of PSII and PSI in 33 species (13 pigment groups) of marine phytoplankton, and the relevance for pulse-amplitude-modulated and fast-repetition-rate fluorometry. Journal of Phycology
    Vitenskapelig artikkel
  • Edvardsen, B; Eikrem, W; Shalchian-Tabrizi, K; Riisberg, I; Johnsen, Geir; Naustvoll, L. (2007) Verrucophora farcimen gen. et sp nov (Dictyochophyceae, Heterokonta) - A bloom-forming ichthyotoxic flagellate from the Skagerrak, Norway. Journal of Phycology
    Vitenskapelig artikkel
  • Johnsen, Geir. (2007) Arctic Life: Bridging ecosystem function using remote sensing technologies. Svalbard Science Forum
    Populærvitenskapelig artikkel
  • Carlsen, BP; Johnsen, Geir; Berge, Jørgen; Kuklinski, P. (2007) Biodiversity patterns of macro-epifauna on different lamina parts of Laminaria digitata and Saccharina latissima collected during spring and summer 2004 in Kongsfjorden, Svalbard. Polar Biology
    Vitenskapelig artikkel
  • Volent, Z; Johnsen, Geir; Sigernes, Fred. (2007) Kelp forest mapping by use of airborne hyperspectral imager. Journal of Applied Remote Sensing
    Vitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
    Leder
  • Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag; Pampanin, Daniella. (2006) The Mytilus edulis population in Svalbard: how and why. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Olsen, Lasse Mork; Öztürk, M.; Sakshaug, Egil; Johnsen, Geir. (2006) Photosynthesis-induced phosphate precipitation in seawater: ecological implications for phytoplankton. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Rodriguez, F; Chauton, Matilde Skogen; Johnsen, Geir; Andresen, Kjersti; Olsen, Lasse Mork; Zapata, M.. (2006) Photoacclimation in phytoplankton: implications for biomass estimates, pigment functionality and chemotaxonomy. Marine Biology
    Vitenskapelig artikkel
  • Johnsen, Geir. (2006) Warming Arctic sees return of blue mussels after 1000 years. National Geographic
    Populærvitenskapelig artikkel
  • Onstad, L; Evertsen, Jussi; Johnsen, Geir. (2006) Snegle på solceller. Gemini
    Populærvitenskapelig artikkel
  • Berge, Jørgen; Johnsen, Geir; Nilsen, Frank; Gulliksen, Bjørn; Slagstad, Dag. (2005) Ocean temperature oscillations enable reappearance of blue mussels Mytilus edulis in Svalbard after 1000 year absence. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Berge, J; Johnsen, Geir; Nilsen, F; Gulliksen, B; Slagstad, D. (2005) Ocean temperature oscillations causes the reappearance of blue mussels in Svalbard after 1000 years of absence. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Bordvik, Hans Otto; Johnsen, Geir. (2005) “En glupsk nellik”. NEWTON websider (NRK)
    Populærvitenskapelig artikkel
  • Indergaard, M; Nordtvedt, M; Johnsen, Geir. (2005) Satellittmålinger for miljøet (SISCAL project, NTNU, IBI). Gemini
    Populærvitenskapelig artikkel
  • Bordvik, Hans Otto; Johnsen, Geir. (2005) “Forskning og foto under vann”. NEWTON websider (NRK)
    Populærvitenskapelig artikkel
  • Burghardt, Ingo; Evertsen, Jussi; Johnsen, Geir; Wägele, Heike. (2005) Solar powered seaslugs - Mutualistic symbiosis of aeolid nudibranchia (Mollusca, Gastropoda, Opisthobranchia) with Symbiodinium. Symbiosis
    Vitenskapelig artikkel
  • Fossmark, Reidar; Johnsen, Geir; Waldum, Helge; Johannesen, Eli Marie. (2005) Rebound acid hypersecretion after long-term inhibition of gastric acid secretion. Alimentary Pharmacology and Therapeutics
    Vitenskapelig artikkel
  • Chauton, Matilde Skogen; Tilstone, Gavin; Legrand, Catherine; Johnsen, Geir. (2004) Changes in pigmentation, bio-optical characteristics and photophysiology, during phytoflagellate succession in mesocosms. Journal of Plankton Research
    Vitenskapelig artikkel
  • Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL prototype evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
    Vitenskapelig artikkel
  • Johansen, Torunn Beate; Johnsen, Geir. (2003) SISCAL End User Requirement evaluation document. www.siscal.net. Satellite-based Information System on Coastal Areas and Lakes. IST 2000
    Vitenskapelig artikkel
  • Chauton, Matilde Skogen; Optun, Odd Inge; Bathen, F. T; Volent, Z.; Gribbestad, Ingrid S.; Johnsen, Geir. (2003) HR MAS 1H NMR spectroscopy analysis of whole cells of marine microalgae. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Figueroa, F. L.; Escassi, L.; Perez-Rodriguez, E.; Korbee, N.; Johnsen, Geir. (2003) Effects of the irradiance in the short-term on accumulation of mycosporine like amino acids in sun and shade species of the red algal genus Porphyra. Photochemistry and Photobiology
    Vitenskapelig artikkel
  • Gileptis, Laura; Johnsen, Geir; Moxness, Helge; Norwich, Inger; Vangen, Steffen. (2002) Modul for mønstergjenkjenning/klassifisering i DynamicImager ved bruk av backpropagation-algoritmen. Piksel'n : Organ for NOBIM (Norsk forening for bildebehandling og mønstergjenkjenning)
    Vitenskapelig artikkel
  • Millie, David; Schofield, Oscar; Kirkpatrick, Gary J.; Johnsen, Geir; Evens, Tim J.. (2002) Using absorbance and fluorescence spectra to discriminate microalgae. European journal of phycology
    Vitenskapelig artikkel
  • Johnsen, Geir; Børsheim, Knut Yngve; Johansen, Torunn Beate. (2002) Production and mortality of phytoplankton and sea-ice microalgae in the southern ocean. Rapportserie (Norsk polarinstitutt)
    Vitenskapelig artikkel
  • Wägele, Heike; Johnsen, Geir. (2001) New results on histology and photosynthetic performance of solar-powered� opisthobranchs (Mollusca, Gastropoda, Opisthobranchia) containing symbiotic chloroplasts or zooxanthellae. Organisms Diversity & Evolution
    Vitenskapelig artikkel
  • Legrand, Catherine; Johnsen, Geir; Graneli, Edna; Sakshaug, Egil. (2001) (Proceedings of the 9th International conference on Harmful Algal Blooms. Hobart, Tasmania, 7-11 February 2000.) Effect of polyamines on growth and toxicity of Chrysochromulina leadbeateri, Haptophytae. Phycologia
    Vitenskapelig artikkel
  • Graneli, Edna; Legrand, Catherine; Carlsson, Per; Johnsen, Geir; Maestrini, Serge Y.; Reichelt, Michael. (2001) (Proceedings of the 9th International conference on Harmful Algal Blooms. Hobart, Tasmania, 7-11 February 20). Structuration of marine phytoplankton communities subjected to different levels of N, P and Si limitation in a mesocosm experiment (summary paper). Phycologia
    Vitenskapelig artikkel
  • Legrand, Catherine; Johansson, Niclas; Johnsen, Geir; Børsheim, Knut Yngve; Graneli, Edna. (2001) Phagotrophy and toxicity in the photosynthetic Prymnesium patelliferum (Haptophyte). Limnology and Oceanography
    Vitenskapelig artikkel
  • Seppala, J; Johnsen, Geir; Babichenko, S; Leeben, A; Poryvkina, L; Shalapyonok, [Mangler fornavn]. (1998) In vivo light absorption by photosynthetic and photoprotective algal pigments: Methodology and the effects of light acclimation and nutrient limitation. Report Series in Geophysics
    Vitenskapelig artikkel
  • Johnsen, Geir; Dalløkken, Runar; Aure, J; Skjoldal, H. R. (1998) Photophysiology and environmental conditions during a toxic bloom of Chrysochromulina leadbeateri (Prymnesiophyceae). International symposium on Harmful Algal Blooms
    Vitenskapelig artikkel
  • Johnsen, Geir; Eikrem, W.; Dalløkken, R.; Aure, J.; Skjoldal, H. R.. (1998) Physiology and environmental conditions during a toxic blooms of Chrysochromulina leadbeateri Prymnesiophyceae. Journal of Phycology
    Vitenskapelig artikkel
  • Grzymski, J.; Johnsen, Geir; Sakshaug, Egil. (1997) The significance of intracellular self-shadingon the bio-optical properties of brown, red and green macroalgal species. Journal of Phycology
    Vitenskapelig artikkel
  • Johnsen, Geir; Prezelin, B. B.; Jovine, R. V. M.. (1997) Fluorescence excitation spectra and light utiliation in two red tide dinoflagellates. Limnology and Oceanography
    Vitenskapelig artikkel
  • Millie, D.; Schofield, O. M.; Kirkpatrick, G. J.; Johnsen, Geir; Tester, P. A.; Vinyard, B. T.. (1997) Phytoplankton pigments and absorption spectra as potential bio-markers for harmful algal blooms: A case study of the Florida red-tide dinoflagellat Gymnodinium breve. Limnology and Oceanography
    Vitenskapelig artikkel
  • Grzymski, J.; Johnsen, Geir; Sakshaug, Egil. (1997) The significance of intracellular self-shading on the bio-optical properties of brown, red and green macroalgal species. Journal of Phycology
    Vitenskapelig artikkel
  • Vernet, M.; Mitchell, B.G.; Sakshaug, Egil; Johnsen, Geir; Iturriaga, R.; Wassmann, P.. (1996) Evidence for a novel pigment with in vivo absorption maximum at 708 nm associated with Phaeocystis cf. pouchetii blooms. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Schofield, O.; Prezelin, B. B.; Johnsen, Geir. (1996) Wavelength-dependency of maximum quantum yield of carbon fixation for two red tide dinoflagellates, Heterocapsa pygmaea and prorocentrum minimum. Journal of Phycology
    Vitenskapelig artikkel
  • Johnsen, Geir; Sakshaug, Egil. (1996) Light harvesting in bloom-forming marine phytoplankton: Species-specifity and photoacclimation,. Scientia Marina
    Vitenskapelig artikkel
  • Johnsen, Geir; Volent, Z; Tangen, K; Sakshaug, Egil. (1996) Time-series of potential toxic phytoplankton blooms in North European waters in 1993 using the SEAWATCH-Europe buoy system. EOS
    Vitenskapelig artikkel
  • Vernet, M.; Mitchell, B. G.; Sakshaug, Egil; Johnsen, Geir; Iturriaga, R.; Wassmann, P.. (1996) Evidence for a novel pigment with in vivo absorption maximum at 708 nm associated with Phaeocystis sp. blooms. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Millie, D; Shofield, O. M; Kirkpatrick, G. J; Tester, P. A; Johnsen, Geir. (1996) Using bio-optical characterisics as bio-markers for harmful algal blooms: A case study of the Florida red-tide dinoflagellate,. EOS
    Vitenskapelig artikkel
  • Johnsen, Geir; Sakshaug, Egil. (1995) Light harvesting in bloom-forming marine phytoplankton: species-specificity and photoadaption. Scientia Marina
    Vitenskapelig artikkel
  • Egeland, E.; Johnsen, Geir; Eikrem, W.; Liaaen-Jensen, S.; Throndsen, J.. (1995) The pigments of Bathycoccus prasinos. Journal of Phycology
    Vitenskapelig artikkel
  • Jovine, R. V.; Johnsen, Geir; Prezelin, B. B.. (1995) Isolation of membrane bound chlorophyll a-chlorofhyll c binding light harvesting complexes from the dinoflagellates heterocapsa pygmaea and Prorocentrum minimum. Photosynthesis Research
    Vitenskapelig artikkel
  • Johnsen, Geir; Nelson, N. B.; Jovine, R. V. M.; Prezelin, B. B.. (1994) Chromoprotein- and pigment-dependent modeling of spectral light absorption in two dinoflagellates, Prorocentrum minimum and Heterocapsa pygmaea. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Jovine, R. V; Johnsen, Geir; Prezelin, B. B. (1994) Photoadaptation of Prorocentrum minimum and Heterocapsa pygmaea (Dinoflagellates): Chromoprotein changes and the consequenses for spectral absorption. EOS
    Vitenskapelig artikkel
  • Jovine, R. V.; Schofield, O.; Johnsen, Geir; Prezelin, B. B.. (1994) Photoacclimatory differences in the light-harvesting complex of the bloom forming dinoflagellates Heterocapsa pygmaea and Prorocentrum minimum. Journal of Phycology
    Vitenskapelig artikkel
  • Johnsen, Geir; Samset, O.; Granskog, L.; Sakshaug, Egil. (1994) In vivo absorption characteristics in 10 classes of phytoplankton: Taxonomic characteristics and responses to photoadaption by means of discriminant and HPLC analysis. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Johnsen, Geir; Sakshaug, Egil. (1993) Bio-optical characteristics and photoadaptive responses in the toxic and bloomforming dinoflagellates Gyrodinium aureolum, Gymnodinium galatheanum two strains of Prorocentrum minium. Journal of Phycology
    Vitenskapelig artikkel
  • Gilstad, Mona; Johnsen, Geir; Sakshaug, Egil. (1993) Photosynthetic parameters, pigment composition and respiration rates of the marine diatom Skeletonema costatum grown in continuous light and a 12:1 light-dark cycle. Journal of Plankton Research
    Vitenskapelig artikkel
  • Volent, Zsolt; Johnsen, Geir. (1993) Presentation of an optical sensor-"OPTISENS" designed for Eulerian measurements of Phytoplankton on a buoy. Underwater light measurements. Proceedings from International Symposium on high latitude optics.
    Vitenskapelig artikkel
  • Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1992) Bio-optical characteristicts of phytoplankton in relation to remote sensing. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
    Vitenskapelig artikkel
  • Volent, Zsolt; Johnsen, Geir. (1992) Presentation of an optical sensor-"OPTISENS" designed for Eulerian measurements of Phytoplankton on a moored buoy. ABOOS (Autonomous Bio-Optical Observing Systems) Scientific Symposium : Abstracts
    Vitenskapelig artikkel
  • Johnsen, Geir; Sakshaug, Egil; Vernet, Maria. (1992) Pigment composition, spectral characteriation and photosynthetic parameters in Chrysochromulina polylepis. Marine Ecology Progress Series
    Vitenskapelig artikkel
  • Johnsen, Geir. (1991) Proceedings from a scientific working meeting. Fisken og Havet
    Vitenskapelig artikkel
  • Johnsen, Geir; Hegseth, Else Nøst. (1991) Photoadaptation of sea-ice microalgae in the Barents Sea. Polar Biology
    Vitenskapelig artikkel
  • Johnsen, Geir. (1991) Identification of Chrysochromulina leadbeateri by means of remote sensing. Fisken og Havet
    Vitenskapelig artikkel
  • Sakshaug, Egil; Johnsen, Geir; Samset, Oddgeir; Zsolt, Volent. (1991) Identification of phytoplankton blooms by means of remote sensing. Environment Northern Seas
    Vitenskapelig artikkel
  • Sakshaug, Egil; Johnsen, Geir; Andresen, Kjersti; Vernet, Maria. (1991) Modeling of light-dependent algal photosynthesis and growth: Experiments with the Barents Sea diatoms Thalassiosira nordensskioeldii and Chaetocero furcellatus. Deep-Sea Research Part II: Topical Studies in Oceanography
    Vitenskapelig artikkel

Kunstneriske produksjoner

  • Snyder, Mike; Berge, Jørgen; Johnsen, Geir; Mckee, David. (2021) “Into the dark” documentary by Mike Snyder following Jørgen Berge (UiT), Geir Johnsen (NTNU) and David McKee (Uni Strathclyde) during Polar Night marine ecology work. .
    Film

Bøker

  • Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Polar night marine ecology - life and light in the dead of night. Springer Advances in Polar Ecology (0)
    Vitenskapelig antologi/Konferanseserie
  • Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2012) Phytoplankton Pigments: Characterization, Chemotaxonomy and Applications in Oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2012)
    Vitenskapelig antologi/Konferanseserie
  • Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Phytoplankton pigments : characterization, chemotaxonomy and applications in oceanography. Cambridge University Press Cambridge Environmental Chemistry Series (2011)
    Vitenskapelig antologi/Konferanseserie
  • Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit M.. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
    Fagbok
  • Sakshaug, Egil; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
    Vitenskapelig antologi/Konferanseserie
  • Sakshaug, E.; Johnsen, Geir; Kovacs, Kit. (2009) Ecosystem Barents Sea. Tapir Akademisk Forlag Tapir Akademisk Forlag
    Lærebok
  • Sakshaug, Egil; Johnsen, Geir. (2005) Algal cultures, Analogues of Blooms and Applications. Multi-Science Publishing Multi-Science Publishing
    Vitenskapelig antologi/Konferanseserie
  • Syvertsen, E.; Hegseth, E; Johnsen, Geir; Sakshaug, Egil; Gulliksen, B; Lønne, O. J. (1992) Livet i isen (The life in the ice). In Økosystem Barentshavet. [Mangler utgivernavn]
    Fagbok
  • Sakshaug, Egil; Kristiansen, S; Syvertsen, E; Eilertsen, H. C; Gilstad, M; Hegseth, E. N. (1992) Planktonalger (Phytoplankton). In Økosystem Barentshavet. [Mangler utgivernavn]
    Fagbok

Del av bok/rapport

  • Zolich, Artur Piotr; Faltynkova, Andrea; Johnsen, Geir; Johansen, Tor Arne. (2022) Portable Catamaran Drone - an uncrewed sampling vehicle for micro-plastics and aquaculture research.
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Berge, Jørgen; Johnsen, Geir. (2020) Life and Light at the Dead of Night. Springer
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Cohen, Jonathan H.; Berge, Jørgen; Moline, Mark A.; Johnsen, Geir; Zolich, Artur Piotr. (2020) Light in the Polar Night. Springer
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Mogstad, Aksel Alstad; Berge, Jørgen; Cohen, Jonathan H.. (2020) Operative Habitat Mapping and Monitoring in the Polar Night. Springer
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Leu, Eva; Gradinger, Rolf. (2020) Marine Micro- and Macroalgae in the Polar Night. Springer
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Berge, Jørgen; Johnsen, Geir; Cohen, Jonathan H.. (2020) Introduction. Springer
    Innledning
  • Pavlov, Alexey K.; Leu, Eva; Hanelt, Dieter; Bartsch, Inka; Karsten, Ulf; Hudson, Stephen. (2019) The Underwater Light Climate in Kongsfjorden and Its Ecological Implications. Springer
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Zolich, Artur Piotr; De La Torre, Pedro R.; Rodwell, Shane; Geoffroy, Maxime; Johnsen, Geir; Berge, Jørgen. (2018) An ice-tethered buoy for fish and plankton research. IEEE conference proceedings
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Ludvigsen, Martin; Thorsnes, Terje; Hansen, Roy Edgar; Sørensen, Asgeir Johan; Johnsen, Geir; Lågstad, Petter Arthur. (2015) Underwater vehicles for environmental management in coastal areas. IEEE conference proceedings
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Ødegård, Øyvind; Ludvigsen, Martin; Johnsen, Geir; Sørensen, Asgeir Johan; Ekehaug, Stefan; Dukan, Fredrik. (2014) Managing data from multiple sensors in an interdisciplinary research cruise. Amsterdam University Press
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Volent, Zsolt; Dierssen, Heidi; Pettersen, Ragnhild; Ardelan, Murat Van; Søreide, Fredrik. (2013) Underwater hyperspectral imagery to create biogeochemical maps of seafloor properties. Woodhead Publishing Limited
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Ludvigsen, Martin; Johnsen, Geir; Lågstad, Petter Arthur; Sørensen, Asgeir Johan; Ødegård, Øyvind. (2013) Scientific operations combining ROV and AUV in the Trondheim Fjord. IEEE conference proceedings
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Brunet, Christophe; Johnsen, Geir; Lavaud, Johan; Roy, Suzanne. (2011) Pigments and photoacclimation processes. Cambridge University Press
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Bricaud, Annick; Nelson, Norman; Prézelin, Barbara; Bidigare, Robert. (2011) In vivo bio-optical properties of phytoplankton pigments. Cambridge University Press
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Moline, Mark; Pettersson, Lasse H.; Pinckney, J. L.; Pozdnyakov, Dmitry; Egeland, Einar Skarstad. (2011) Optical monitoring of phytoplankton bloom pigment signatures. Cambridge University Press
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Llewellyn, Carole A.; Roy, Suzanne; Johnsen, Geir; Egeland, Einar Skarstad; Chauton, Matilde ; Hallegraeff, Gustaff. (2011) Perspectives on future directions. Cambridge University Press
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Preface. Cambridge University Press
    Forord
  • Roy, Suzanne; Llewellyn, Carole; Egeland, Einar Skarstad; Johnsen, Geir. (2011) Acknowledgements. Cambridge University Press
    Annet
  • Johnsen, Geir; Volent, Z; Sakshaug, E.; Sigernes, Fred; Pettersson, L.H.. (2009) Remote sensing in the Barents Sea. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Sakshaug, E.; Johnsen, Geir; Kristiansen, Svein; Quillfeldt, C.v.; Rey, F.; Slagstad, D.. (2009) Phytoplankton and primary production. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Sakshaug, E.; Johnsen, Geir; Volent, Z. (2009) Light. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Quillfeldt, C.v.; Hegseth, E.N.; Johnsen, Geir; Sakshaug, E.; Syvertsen, E.E.. (2009) Ice algae. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • von Quillfeldt, Cecilie H.; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik. (2009) Ice algae. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • von Quillfeldt, Cecilie; Hegseth, Else Nøst; Johnsen, Geir; Sakshaug, Egil; Syvertsen, Erik E.. (2009) Ice algae. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Sakshaug, Egil; Johnsen, Geir; Kristiansen, Svein; von Quillfeldt, Cecilie; Rey, Francisco; Slagstad, Dag. (2009) Phytoplankton and primary production. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Sakshaug, Egil; Johnsen, Geir; Volent, Z.. (2009) Light. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Volent, Zsolt; Sakshaug, Egil; Sigernes, Fred; Pettersson, Lasse H.. (2009) Remote sensing in the Barents Sea. Tapir Akademisk Forlag
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Sakshaug, Egil; Johnsen, Geir. (2005) Absorption, fluorescence excitation and photoacclimation in phytoplankton. Multi-Science Publishing
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Samset, O.; Sakshaug, Egil. (1998) Bio-optical classification of potential harmful chlorophyll c -containing prymnesiophyte blooms in Scandinavian water.
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Volent, Z.; Tangen, K.; Sakshaug, Egil. (1997) Time series of harmful and benign phytoplankton blooms in northwest European waters using the Seawatch buoy system.
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel
  • Johnsen, Geir; Volent, Z.; Tangen, K.; Sakshaug, Egil. (1997) Time series of harmful and benign phytoplankton blooms in northwest European waters using the Seawatch buoy system.
    Vitenskapelig Kapittel/Artikkel/Konferanseartikkel

Rapport

  • Nøland, Annecken; Johnsen, Geir; Aberle-Malzahn, Nicole. (2022) Autonomous Underwater Vehicle (AUV) based study of zooplankton communities, using a silhouette camera and artificial intelligence. NTNU
    Mastergradsoppgave
  • Johnsen, Geir; Aberle-Malzahn, Nicole; Fragoso, Glaucia; Thu, Maren. (2022) Phytoplankton Spring Bloom Mapping in Coastal Areas Using Autonomous Underwater Vehicle (AUV) and Optical Approaches. NTNU
    Mastergradsoppgave
  • Nevstad, Malin Bø; Johnsen, Geir; Bakken, Torkild; Larsen, Martin Kvisvik; Mogstad, Aksel Alstad. (2022) Use of different imaging systems for ROV-based mapping of complex benthic habitats. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Marnor, Camilla Mult; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Mapping distribution patterns of brittle stars using ROV-based imaging. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Bjerkvoll, Mikkel; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad. (2022) Aerial and underwater hyperspectral imagery for shallow benthic nature type mapping. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Søreng, Marte Opsahl; Johnsen, Geir; Bakken, Torkild; Mogstad, Aksel Alstad; Gryte, Kristoffer. (2022) Mapping of Zostera Habitat in the Sublittoral Zone using Underwater Hyperspectral Imaging and Unmanned Surface Vehicle. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Ringvold, Halldis; Johnsen, Geir; Andersen, Tom. (2021) Studies on Echinodermata from the NE Atlantic Ocean - Spatial distribution and abundance of Asteroidea, including taxonomic and molecular studies on Crossaster and Henricia genera - Value-chain results, including test fishery, biology, market and nutritional analysis on Parastichopus tremulus (Holothuroidea) from the Norwegian coast. Doktoravhandlinger ved NTNU (2021-254)
    Doktorgradsavhandling
  • Mogstad, Aksel Alstad; Johnsen, Geir; Sørensen, Asgeir Johan; Ludvigsen, Martin. (2021) Underwater hyperspectral imaging as a tool for benthic habitat mapping. Doktoravhandlinger ved NTNU (2021/271)
    Doktorgradsavhandling
  • Graham, Lisa Kristine Hernandez; Johnsen, Geir; Christensen-Dalsgaard, Signe. (2019) A pilot study assessing drones for mapping and monitoring of European shags. Institutt for biologi, NTNU
    Mastergradsoppgave
  • Fjærtoft, Kaja Lønne; Bakken, Torkild; Johnsen, Geir; Ludvigsen, Martin. (2018) Macroalgal detritus: Physical variables and impacts on the benthic macrofaunal community. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Ødegård, Øyvind; Sørensen, Asgeir Johan; Johnsen, Geir; Ludvigsen, Martin; Hansen, Roy Edgar; Maarleveld, Thijs. (2018) Towards Autonomous Operations and Systems in Marine Archaeology. Doktoravhandlinger ved NTNU (IMT-12)
    Doktorgradsavhandling
  • Strømsholm, Jørgen; Johnsen, Geir; Ludvigsen, Martin. (2018) Eyes beneath the surface - using a miniROV to reveal habitat and dietary choices of the European shag. NTNU MSc thesis
    Mastergradsoppgave
  • Kauko, Hanna Maria; Johnsen, Geir; Assmy, Phillipp. (2018) Light response and acclimation of macroalgae in a changing Arctic. Doktoravhandlinger ved NTNU (2018)
    Doktorgradsavhandling
  • Nornes, Stein Melvær; Sørensen, Asgeir Johan; Ludvigsen, Martin; Johnsen, Geir; Schjølberg, Ingrid; Ånonsen, Kjetil Bergh. (2018) Guidance and Control of Marine Robotics for Ocean Mapping and Monitoring. Doktoravhandlinger ved NTNU (2018:202)
    Doktorgradsavhandling
  • Mynors, Julie; Johnsen, Geir; Wernand, Marcel; Volent, Zsolt. (2017) Ocean Colour and Phytoplankton Dynamics - An examination of the Forel-Ule scale in a modern context. NTNU Trondheim
    Mastergradsoppgave
  • Kamilla, Sporsheim; Sporsheim, Kamilla; Johnsen, Geir; Reitan, Kjell Inge; Evertsen, Antii Jussi. (2017) Astaxanthin as a biomarker for fish feed loading in the marine ecosystem. NTNU, Trondheim
    Mastergradsoppgave
  • Kjeken, John; Johnsen, Geir; Ludvigsen, Martin; Thorsnes, Terje; Lågstad, Petter Arthur. (2017) The growth of benthic organisms in a dumping ground for military bombs and munitions. NTNU, Trondheim
    Mastergradsoppgave
  • Johnsen, Geir; Sandbu, Marthe; Assmy, Philipp. (2017) High Arctic Sea-Ice Algae: The Use of Rapid Light Curves to Assess Photosynthetic Performance of Different Ice-Algal Communities. Master science NTNU
    Mastergradsoppgave
  • Andersson, Ingvild Henriette Kristin; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin. (2017) Bio-optical diversity on cold water coral habitats. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Alvsvåg, Dora Marie; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Berge, Jørgen. (2017) Mapping of a seagrass habitat in Hopavågen, Sør-Trøndelag, with the use of an Autonomous Surface Vehicle combined with optical techniques. Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Paulsen, Emil; Bakken, Torkild; Ramirez-Llodra, Eva; Johnsen, Geir. (2017) Community structure and biodiversity of the benthic megafauna at the inactive hydrothermal site Mohn's Treasure, on the Mohn's Ridge, Arctic Mid-Ocean Ridge (AMOR) . Norges teknisk-naturvitenskapelige universitet Norges teknisk-naturvitenskapelige universitet
    Mastergradsoppgave
  • Jakobsen, June; Johnsen, Geir; Bakken, Torkild; Ludvigsen, Martin; Karlsen, Svein. (2016) The Tautra Cold-Water Coral Reef - Mapping and describing the biodiversity of a cold-water coral reef ecosystem in the Trondheimsfjord by use of multi-beam echo sounding and video mounted on a remotely operated vehicle. NTNU
    Mastergradsoppgave
  • Håpnes, Sverre Julian; Johnsen, Geir; Ludvigsen, Martin; Lågstad, Petter Arthur. (2016) Mapping of demersal fish and benthos by AUV equipped with optical and acoustic imagers at 600 m depth in Trondheimsfjorden. NTNU MSc
    Mastergradsoppgave
  • Liefmann, Stepha