• Analysis of merged SMMR-SSMI time series of Arctic and Antarctic sea ice parameters 1978-1995 

      Bjørgo, Einar; Johannessen, Ola M.; Miles, Martin W. (Journal article; Peer reviewed, 1997-02-15)
      The most consistent means of investigating the global sea ice cover is by satellite passive microwave sensors, as these are independent of illumination and cloud cover. The Nimbus 7 Scanning Multichannel Microwave Radiometer ...
    • Application of a hybrid EnKF-OI to ocean forecasting 

      Counillon, François; Sakov, Pavel; Bertino, Laurent (Journal article, 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 ...
    • Arctic Sea level Budget Assessment During the GRACE/Argo Time Period 

      Raj, Roshin Pappukutty; Andersen, Ole Baltazar; Johannessen, Johnny Andre; Benjamin, Gutknech; Chatterjee, Sourav; Rose, Stine; Bonaduce, Antonio; Horwath, Martin; Ranndal, Heidi; Richter, Kristin; Palanisamy, Hindumathi; Ludwigsen, Carsten; Bertino, Laurent; Nilsen, Jan Even Øie; Knudsen, Per; Hogg, Anna E.; Cazenave, Anny; Benveniste, Jérôme (Journal article; Peer reviewed, 2020)
      Sea level change is an important indicator of climate change. Our study focuses on the sea level budget assessment of the Arctic Ocean using: (1) the newly reprocessed satellite altimeter data with major changes in the ...
    • Barents Sea seasonal ice zone features and processes from ERS 1 synthetic aperture radar: Seasonal Ice Zone Experiment 1992 

      Sandven, Stein; Johannessen, Ola M.; Miles, Martin W.; Pettersson, Lasse H.; Kloster, Kjell (Journal article; Peer reviewed, 1999-07-15)
      Sea ice features and processes in the Barents Sea were studied during the Seasonal Ice Zone Experiment 1992 (SIZEX92), a dedicated ERS 1 satellite synthetic aperture radar (SAR) field campaign carried out in March 1992. ...
    • Coastal wind field retrievals from ERS synthetic aperture radar images 

      Korsbakken, E.; Johannessen, Johnny A.; Johannessen, Ola M. (Journal article; Peer reviewed, 1998-04-15)
      A unique series of European Remote Sensing Satellite (ERS) 1 and 2 C band synthetic aperture radar (SAR) images was obtained off the southern coast of Norway during the Coast Watch’95 experiment in September 1995. In this ...
    • Cover ERS-1/2 SAR monitoring of dangerous ice phenomena along the western part of Northern Sea Route 

      Johannessen, Ola M.; Sandven, Stein; Kloster, Kjell; Pettersson, Lasse H.; Melentyev, V. V.; Bobylev, Leonid P.; Kondratyev, K. Ya. (Journal article, 1997-08-01)
    • Cover ERS-1/2 SAR monitoring of dangerous ice phenomena along the western part of Northern Sea Route 

      Johannessen, Ola M.; Sandven, Stein; Kloster, Kjell; Pettersson, Lasse H.; Melentyev, V. V.; Bobylev, Leonid P.; Kondratyev, K. Ya. (Journal article; Peer reviewed, 1997-08-01)
    • Diapycnal Mixing in a Conceptual Model of the Atlantic Meridional Overturning Circulation 

      Marzeion, Ben; Drange, Helge (Journal article, 2006)
      A three-box model of the Atlantic Ocean is used to examine the influence different parameterisations of the diapycnal mixing may have on the large scale dynamics of the ocean circulation. Special emphasis is given to the ...
    • An ERS 1 synthetic aperture radar image of atmospheric lee waves 

      Vachon, P. W.; Johannessen, Ola M.; Johannessen, Johnny A. (Journal article; Peer reviewed, 1994-11-15)
      An ERS 1 synthetic aperture radar (SAR) image of the island Hopen shows a distinct 7.6-km wavelength wave phenomenon near the island. This wave phenomenon is interpreted as the surface imprint on open water of atmospheric ...
    • Evaluating Global Ocean Carbon Models: The Importance of Realistic Physics 

      Doney, S. C.; Lindsay, K.; Caldeira, Ken; Campin, J. M.; Drange, Helge; Dutay, J. C.; Follows, M.; Gao, Yongqi; Gnanadesikan, A.; Gruber, N.; Ishida, A.; Joos, Fortunat; Madec, G.; Maier-Reimer, E.; Marshall, J. C.; Matear, R. J.; Monfray, P.; Mouchet, A.; Najjar, R.; Orr, J. C.; Plattner, G. K.; Sarmiento, J. L.; Schlitzer, R.; Slater, R.; Totterdell, I. J.; Weirig, M. F.; Yamanaka, Y.; Yool, A. (Peer reviewed; Journal article, 2004-09-15)
      A suite of standard ocean hydrographic and circulation metrics are applied to the equilibrium physical solutions from 13 global carbon models participating in phase 2 of the Ocean Carbon-cycle Model Intercomparison Project ...
    • Evaluation of ocean carbon cycle models with data-based metrics 

      Matsumoto, K.; Sarmiento, J. L.; Key, R. M.; Aumont, O.; Bullister, J. L.; Caldeira, Ken; Campin, J. M.; Doney, S. C.; Drange, Helge; Dutay, J. C.; Follows, M.; Gao, Yongqi; Gnanadesikan, A.; Gruber, N.; Ishida, A.; Joos, Fortunat; Lindsay, K.; Maier-Reimer, E.; Marshall, J. C.; Matear, R. J.; Monfray, P.; Mouchet, A.; Najjar, R.; Plattner, G. K.; Schlitzer, R.; Slater, R.; Swathi, P. S.; Totterdell, I. J.; Weirig, M. F.; Yamanaka, Y.; Yool, A.; Orr, J. C. (Journal article; Peer reviewed, 2004-04-02)
      New radiocarbon and chlorofluorocarbon-11 data from the World Ocean Circulation Experiment are used to assess a suite of 19 ocean carbon cycle models. We use the distributions and inventories of these tracers as quantitative ...
    • Formulation of the planetary boundary layer feedback in the Earth´s climate system 

      Esau, Igor N. (Journal article, 2008)
      Recent publications have revealed that the state-of-the-art climate models are probably not sensitive enough to observed changes in the surface air temperature. This fact calls for the search of feedback mechanisms making ...
    • 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 (Journal article, 2009-11-16)
    • Greenland Sea Odden sea ice feature: Intra-annual and interannual variability 

      Shuchman, Robert A.; Josberger, Edward G.; Russel, Catherine A.; Fischer, Kenneth W.; Johannessen, Ola M.; Johannessen, Johnny A.; Gloersen, Per (Journal article; Peer reviewed, 1998-06-15)
      The “Odden” is a large sea ice feature that forms in the east Greenland Sea that may protrude eastward to 5 °E from the main sea ice pack (at about 8 °W) between 73° and 77 °N. It generally forms at the beginning of the ...
    • Heat in the Barents Sea: Transport, storage, and surface fluxes 

      Smedsrud, Lars Henrik; Ingvaldsen, Randi; Nilsen, Jan Even Øie; Skagseth, Øystein (Journal article, 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 ...
    • 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 (Journal article, 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 plankton ...
    • A Hybrid Coordinate Ocean Model for shelf sea simulation 

      Winther, Nina Gjerde; Evensen, Geir (Journal article, 2006-03-03)
      The general circulation in the North Sea and Skagerrak is simulated using the Hybrid Coordinate Ocean Model (HYCOM). Although HYCOM was originally de- veloped for simulations of the open ocean, it has a design which should ...
    • The impact of ensemble filter definition on the assimilation of temperature profiles in the tropical Pacific 

      Leeuwenburgh, O.; Evensen, Geir; Bertino, Laurent (Journal article; Peer reviewed, 2005-10)
      The traditional analysis scheme in the Ensemble Kalman Filter (EnKF) uses a stochastic perturbation or randomization of the measurements which ensures a correct variance in the updated ensemble. An alternative so called ...
    • Indian Ocean: Validation of the Miami Isopycnic Coordinate Ocean Model and ENSO events during 1958–1998 

      Haugen, Vibeke E.; Johannessen, Ola M.; Evensen, Geir (Journal article, 2002-05-25)
      In the Indian Ocean, in situ data are sparse both in time and space. Therefore, numerical models are one of the major tools for further understanding of the ocean circulation. We have implemented, validated, and done a 40 ...
    • Influence of horizontal model grid resolution on the simulated primary production in an embedded primary production model in the Norwegian Sea 

      Hansen, Cecilie; Samuelsen, Annette (Journal article, 2009)
      The purpose of this paper is to investigate the influence of horizontal grid resolution in a physical model on an embedded primary production model. The area for the experiment was along the west coast of Norway, from 60◦N ...