Geir Johnsen

7.9k total citations
145 papers, 5.4k citations indexed

About

Geir Johnsen is a scholar working on Oceanography, Ecology and Global and Planetary Change. According to data from OpenAlex, Geir Johnsen has authored 145 papers receiving a total of 5.4k indexed citations (citations by other indexed papers that have themselves been cited), including 86 papers in Oceanography, 61 papers in Ecology and 23 papers in Global and Planetary Change. Recurrent topics in Geir Johnsen's work include Marine and coastal ecosystems (63 papers), Marine Biology and Ecology Research (21 papers) and Marine and coastal plant biology (21 papers). Geir Johnsen is often cited by papers focused on Marine and coastal ecosystems (63 papers), Marine Biology and Ecology Research (21 papers) and Marine and coastal plant biology (21 papers). Geir Johnsen collaborates with scholars based in Norway, United States and United Kingdom. Geir Johnsen's co-authors include Egil Sakshaug, Per J. Jakobsen, Jørgen Berge, Martin Ludvigsen, Kjersti Andresen, Kasper Hancke, Einar Skarstad Egeland, Suzanne Roy, Carole A. Llewellyn and Asgeir J. Sørensen and has published in prestigious journals such as PLoS ONE, The Science of The Total Environment and Remote Sensing of Environment.

In The Last Decade

Geir Johnsen

140 papers receiving 5.1k citations

Peers — A (Enhanced Table)

Peers by citation overlap · career bar shows stage (early→late) cites · hero ref

Name h Career Trend Papers Cites
Geir Johnsen Norway 43 3.0k 2.0k 957 829 723 145 5.4k
Karen Helen Wiltshire Germany 35 3.2k 1.1× 2.8k 1.4× 1.2k 1.2× 1.1k 1.4× 872 1.2× 193 5.4k
John T. O. Kirk Australia 14 3.6k 1.2× 1.7k 0.9× 1.3k 1.4× 824 1.0× 560 0.8× 28 5.3k
Heidi M. Sosik United States 34 2.7k 0.9× 1.5k 0.8× 628 0.7× 535 0.6× 467 0.6× 95 3.6k
Hiroaki Saito Japan 41 3.0k 1.0× 1.9k 1.0× 517 0.5× 1.3k 1.5× 590 0.8× 224 5.5k
Alan J. Lewitus United States 33 2.6k 0.9× 1.6k 0.8× 2.0k 2.1× 601 0.7× 547 0.8× 68 4.6k
André Visser Denmark 40 2.6k 0.9× 1.8k 0.9× 914 1.0× 1.5k 1.8× 347 0.5× 102 5.3k
Cèlia Marrasé Spain 38 3.4k 1.1× 2.7k 1.3× 946 1.0× 620 0.7× 812 1.1× 108 4.8k
Elena Litchman United States 49 6.5k 2.2× 4.6k 2.3× 3.7k 3.9× 1.3k 1.6× 890 1.2× 99 10.3k
Oscar Schofield United States 57 8.5k 2.9× 5.1k 2.6× 1.7k 1.8× 2.2k 2.6× 1.4k 1.9× 278 12.6k
J. Rozema Belgium 51 807 0.3× 1.9k 0.9× 403 0.4× 513 0.6× 965 1.3× 291 9.6k

Countries citing papers authored by Geir Johnsen

Since Specialization
Citations

This map shows the geographic impact of Geir Johnsen's research. It shows the number of citations coming from papers published by authors working in each country. You can also color the map by specialization and compare the number of citations received by Geir Johnsen with the expected number of citations based on a country's size and research output (numbers larger than one mean the country cites Geir Johnsen more than expected).

Fields of papers citing papers by Geir Johnsen

Since Specialization
Physical SciencesHealth SciencesLife SciencesSocial Sciences

This network shows the impact of papers produced by Geir Johnsen. Nodes represent research fields, and links connect fields that are likely to share authors. Colored nodes show fields that tend to cite the papers produced by Geir Johnsen. The network helps show where Geir Johnsen may publish in the future.

Co-authorship network of co-authors of Geir Johnsen

This figure shows the co-authorship network connecting the top 25 collaborators of Geir Johnsen. A scholar is included among the top collaborators of Geir Johnsen based on the total number of citations received by their joint publications. Widths of edges represent the number of papers authors have co-authored together. Node borders signify the number of papers an author published with Geir Johnsen. Geir Johnsen is excluded from the visualization to improve readability, since they are connected to all nodes in the network.

All Works

20 of 20 papers shown
1.
Utne, Ingrid Bouwer, et al.. (2025). Towards ecological integration into socio-technical risk assessment: A multidisciplinary system-theoretic approach. Ocean Engineering. 335. 121760–121760.
2.
Aldridge, David C., et al.. (2024). Biomass estimations of cultivated kelp using underwater RGB images from a mini-ROV and computer vision approaches. Frontiers in Marine Science. 11. 3 indexed citations
3.
Johnsen, Geir, et al.. (2023). Spectral and RGB analysis of the light climate and its ecological impacts using an all-sky camera system in the Arctic. Applied Optics. 62(19). 5139–5139. 4 indexed citations
4.
5.
Williamson, David, Glaucia M. Fragoso, Sanna Majaneva, et al.. (2023). Monitoring Algal Blooms with Complementary Sensors on Multiple Spatial and Temporal Scales. Oceanography. 5 indexed citations
6.
Banas, Neil S., Jørgen Berge, Finlo Cottier, et al.. (2022). Midnight Sun to Polar Night: A Model of Seasonal Light in the Barents Sea. Journal of Advances in Modeling Earth Systems. 14(10). 12 indexed citations
7.
Berge, Jørgen, Maxime Geoffroy, Malin Daase, et al.. (2020). Artificial light during the polar night disrupts Arctic fish and zooplankton behaviour down to 200 m depth. Communications Biology. 3(1). 102–102. 57 indexed citations
8.
Dumke, Ines, Autun Purser, Yann Marcon, et al.. (2018). Underwater hyperspectral imaging as an in situ taxonomic tool for deep-sea megafauna. Scientific Reports. 8(1). 12860–12860. 45 indexed citations
9.
Kauko, Hanna M., Torbjørn Taskjelle, Philipp Assmy, et al.. (2017). Windows in Arctic sea ice: Light transmission and ice algae in a refrozen lead. Journal of Geophysical Research Biogeosciences. 122(6). 1486–1505. 43 indexed citations
10.
Johnsen, Geir, Martin Ludvigsen, Asgeir J. Sørensen, & Lars Martin Sandvik. (2016). The use of underwater hyperspectral imaging deployed on remotely operated vehicles - methods and applications. IFAC-PapersOnLine. 49(23). 476–481. 59 indexed citations
11.
Cronin, Heather, Jonathan H. Cohen, Jørgen Berge, Geir Johnsen, & Mark A. Moline. (2016). Bioluminescence as an ecological factor during high Arctic polar night. Scientific Reports. 6(1). 36374–36374. 24 indexed citations
12.
Nilssen, Ingunn, Ricardo Coutinho, Ingvar Eide, et al.. (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. 112(Pt A). 68–77. 10 indexed citations
13.
Nymark, Marianne, Kasper Hancke, Per Winge, et al.. (2013). Molecular and Photosynthetic Responses to Prolonged Darkness and Subsequent Acclimation to Re-Illumination in the Diatom Phaeodactylum tricornutum. PLoS ONE. 8(3). e58722–e58722. 104 indexed citations
14.
Roy, Suzanne, Carole A. Llewellyn, Einar Skarstad Egeland, & Geir Johnsen. (2011). Phytoplankton pigments : characterization, chemotaxonomy and applications in oceanography. Cambridge University Press eBooks. 262 indexed citations
15.
Moline, Mark A., et al.. (2011). Ice Detection For Under Ice AUV Navigation. The Twenty-first International Offshore and Polar Engineering Conference. 1 indexed citations
16.
Skaala, Øystein, Geir Johnsen, & Bjørn T. Barlaup. (2010). Prioriterte strakstiltak for sikring av ville bestander av laksefisk i Hardangerfjordbassenget i påvente av langsiktige forvaltningstiltak. Duo Research Archive (University of Oslo). 1 indexed citations
17.
Burghardt, Ingo, Jussi Evertsen, Geir Johnsen, & Heike Wägele. (2005). Solar Powered Seaslugs - Mutualistic Symbiosis of Aeolid Nudibranchia (Mollusca, Gastropoda, Opisthobranchia) with Symbiodinium. Symbiosis. 38(3). 227–250. 28 indexed citations
18.
Akse, Leif, et al.. (2002). Landing av usløyd fisk for utnyttelse av biproduktene. Duo Research Archive (University of Oslo). 2 indexed citations
19.
Sakshaug, Egil & Geir Johnsen. (1996). Light harvesting in bloom-forming marine phytoplankton: species-specificity and photoacclimation. Scientia Marina. 60(1). 47–56. 42 indexed citations
20.
Holm, Jens‐Christian, Per J. Jakobsen, & Geir Johnsen. (1985). Increased growth rate in Atlantic salmon parr by using a two-colour diet. Duo Research Archive (University of Oslo). 1 indexed citations

Rankless uses publication and citation data sourced from OpenAlex, an open and comprehensive bibliographic database. While OpenAlex provides broad and valuable coverage of the global research landscape, it—like all bibliographic datasets—has inherent limitations. These include incomplete records, variations in author disambiguation, differences in journal indexing, and delays in data updates. As a result, some metrics and network relationships displayed in Rankless may not fully capture the entirety of a scholar's output or impact.

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