Now showing items 1-20 of 123

    • Spatial heterogeneity of greening and browning between and within bioclimatic zones in northern West Siberia 

      Miles, Victoria; Esau, Igor (IOP Publishing, 2016-10-26)
      Studies of the normalized difference vegetation index (NDVI) have found broad changes in vegetation productivity in high northern latitudes in the past decades, including increases in NDVI (‘greening’) in tundra regions ...
      Journal article
    • A brief history of climate – the northern seas from the Last Glacial Maximum to global warming 

      Eldevik, Tor; Risebrobakken, Bjørg; Bjune, Anne Elisabeth; Andersson, Carin; Birks, Harry John Betteley; Dokken, Trond Martin; Drange, Helge; Glessmer, Mirjam Sophia; Li, Camille; Nilsen, Jan Even Øie; Otterå, Odd Helge; Richter, Kristin; Skagseth, Øystein (Elsevier, 2014-12)
      The understanding of climate and climate change is fundamentally concerned with two things: a well-defined and sufficiently complete climate record to be explained, for example of observed temperature, and a relevant ...
      Journal article
    • Diagnosing and Understanding the AMOC Biases in NorESM 

      Ivanova, Detelina; Bentsen, Mats; Ilicak, Mehmet; Gao, Chuncheng; Drange, Helge (The Authors, 2014)
      We investigate the Atlantic Meridional Overturning Circulation (AMOC) in the Norwegian Earth System Model (NorESM) featuring isopycnal ocean component (MICOM). The Coupled Model Intercomparison Phase 5 (CMIP5) ...
      Conference object
    • Water mass transformation and the North Atlantic Current in three multi-century climate model simulations 

      Langehaug, Helene Reinertsen; Rhines, Peter B.; Eldevik, Tor; Mignot, Juliette; Lohmann, Katja (American Geophysical Union, 2012-11)
      The warm and saline Subtropical Water carried by the North Atlantic Current undergoes substantial transformation on its way to higher latitudes as heat is released from ocean to atmosphere. The geographical distribution ...
      Journal article
    • Changes in the properties and distribution of the intermediate and deep waters in the Fram Strait 

      Langehaug, Helene Reinertsen; Falck, Eva (Elsevier, 2012-04)
      The Fram Strait is the only deep connection between the Arctic Ocean and the Nordic Seas (Greenland, Iceland, and Norwegian Seas), with a sill depth of approximately 2600 m. Consequently, observations from this area ...
      Journal article
    • Mesoscale Eddies Are Oases for Higher Trophic Marine Life 

      Godø, Olav Rune; Samuelsen, Annette; Macaulay, Gavin J.; Patel, Ruben; Hjøllo, Solfrid Sætre; Horne, John; Kaartvedt, Stein; Johannessen, Johnny A. (Public Library of Science, 2012-01-17)
      Mesoscale eddies stimulate biological production in the ocean, but knowledge of energy transfers to higher trophic levels within eddies remains fragmented and not quantified. Increasing the knowledge base is constrained ...
      Peer reviewedJournal article
    • Arctic/Atlantic exchanges via the Subpolar Gyre 

      Langehaug, Helene Reinertsen; Medhaug, Iselin; Eldevik, Tor; Otterå, Odd Helge (American Meteorological Society, 2012)
      In the present study we investigate the decadal variability in the strength and shape of the Subpolar Gyre (SPG) in a 600-year pre-industrial simulation using the Bergen Climate Model. The atmospheric influence on the ...
      Journal article
    • Circulation and transformation of Atlantic and Arctic water masses in climate models 

      Langehaug, Helene Reinertsen (The University of Bergen, 2011-12-09)
      Ocean heat transport and associated heat loss to the atmosphere contributes significantly to the anomalously mild climate of northwestern Europe and its variability. In this thesis, the circulation and transformation of ...
      Doctoral thesis
    • Critical vulnerabilities of marine and sea ice–based ecosystems in the high Arctic 

      Johannessen, Ola M.; Miles, Martin W. (Springer, 2010-12-01)
      The objectives of this paper are to summarise: (1) observed 20th-century and projected 21st-century changes in key components of the Arctic climate system and (2) probable impacts on the Arctic marine environment, with ...
      Peer reviewedJournal article
    • On the Velocity Gradient in Stably Stratified Sheared Flows. Part 2: Observations and Models 

      Kouznetsov, Rostislav D.; Zilitinkevich, Sergej S. (Springer, 2010-05-12)
      Observations of the dependence of the dimensionless wind speed gradient φm as a function of the Monin–Obukhov stability parameter z/Lo under strong stability diverge from results of large-eddy simulation (LES) modelling. ...
      Peer reviewedJournal article
    • Heat in the Barents Sea: Transport, storage, and surface fluxes 

      Smedsrud, Lars Henrik; Ingvaldsen, Randi; Nilsen, Jan Even Øie; Skagseth, Øystein (Copernicus Publications, 2010-01-11)
      A column model is set up for the Barents Sea to explore sensitivity of surface fluxes and heat storage from varying ocean heat transport. Mean monthly ocean transport and atmospheric forcing are synthesised and force the ...
      Journal article
    • Greenland Ice Sheet Elevation Ehange in Winter and Influence of Atmospheric Teleconnections in the Northern Hemisphere 

      Chen, Lin-Ling; Johannessen, Ola M.; Khvorostovsky, Kirill; Wang, Huijun (Institute of atmospheric physics, Chinese academy of sciences, Science press, 2009-11-16)
      Journal article
    • Application of a hybrid EnKF-OI to ocean forecasting 

      Counillon, François; Sakov, Pavel; Bertino, Laurent (Copernicus Publications on behalf of the European Geosciences Union, 2009-10-01)
      Data assimilation methods often use an ensemble to represent the background error covariance. Two approaches are commonly used; a simple one with a static ensemble, or a more advanced one with a dynamic ensemble. The latter ...
      Journal article
    • Sensitivity of remote sensing – derived phytoplankton productivity to mixed layer depth: Lessons from the carbon-based productivity model 

      Milutinović, Svetlana; Behrenfeld, Michael J.; Johannessen, Johnny A.; Johannessen, Truls (American Geophysical Union, 2009-10-01)
      Mixed layer depth (MLD) has long been recognized as having an important influence on underwater light budget and, thus, net primary productivity (NPP) of phytoplankton. The depth- and wavelength-integrated carbon-based ...
      Peer reviewedJournal article
    • Ocean data assimilation systems for GODAE 

      Cummings, James; Bertino, Laurent; Brasseur, Pierre; Fukumori, Ichiro; Kamachi, Masafumi; Martin, Matthew J.; Mogensen, Kristian; Oke, Peter; Testut, Charles Emmanuel; Verron, Jaques; Weaver, Anthony (The Oceanography Society, 2009-09)
      Ocean data assimilation has matured to the point that observations are now routinely combined with model forecasts to produce a variety of ocean products. Approaches to ocean data assimilation vary widely both in terms ...
      Journal article
    • Remote sensing of sea ice 

      Breivik, Lars-Anders; Carrieres, Tom; Eastwood, Steinar; Fleming, Andrew; Girard-Ardhuin, Fanny; Karvonen, Juha; Kwok, Ron; Meier, Walter N.; Mäkynen, Marko; Pedersen, Leif Toudal; Sandven, Stein; Similä, Markku; Tonboe, Rasmus (2009-09)
      Conference object
    • Validation and intercomparison studies within GODAE 

      Hernandez, F.; Bertino, Laurent; Brassington, Gary; Chassignet, E.; Cummings, James; Davidson, Fraser; Drévillon, M.; Garric, Gilles; Kamachi, Masafumi; Lellouche, J.-M.; Mahdon, R.; Martin, Matthew J.; Ratsimandresy, A.; Regnier, C. (The Oceanography Society, 2009-09)
      During the Global Ocean Data Assimilation Experiment (GODAE), seven international operational centers participated in a dedicated modeling system intercomparison exercise from February to April 2008. The objectives were: ...
      Journal article
    • Evaluating two numerical advection schemes in HYCOM for eddy-resolving modelling of the Agulhas Current 

      Backeberg, Bjørn C.; Bertino, Laurent; Johannessen, Johnny A. (Copernicus Publications on behalf of the European Geosciences Union, 2009-06-02)
      A 4th order advection scheme is applied in a nested eddy-resolving Hybrid Coordinate Ocean Model (HYCOM) of the greater Agulhas Current system for the purpose of testing advanced numerics as a means for improving the model ...
      Journal article
    • Hurricane-driven alteration in plankton community size structure in the Gulf of Mexico: A modeling study 

      Gierach, Michelle M.; Subrahmanyam, Bulusu; Samuelsen, Annette; Ueyoshi, Kyozo (American Geophysical Union, 2009-04-03)
      This was the first study to analyze phytoplankton and zooplankton community size structure during hurricane passage. A three-dimensional biophysical model was used to assess ecosystem dynamics, plankton biomass, and ...
      Journal article
    • Semi-empirical Algorithm for the Retrieval of Ecology-Relevant Water Constituents in Various Aquatic Environments 

      Korosov, A. A.; Pozdnyakov, D. V.; Folkestad, Are; Pettersson, Lasse H.; Sørensen, Kai; Shuchman, Robert A. (Molecular Diversity Preservation International (MDPI), 2009-03-10)
      An advanced operational semi-empirical algorithm for processing satellite remote sensing data in the visible region is described. Based on the Levenberg-Marquardt multivariate optimization procedure, the algorithm is ...
      Journal article