Now showing items 247-266 of 1194

    • Downscaling an intense precipitation event in complex terrain: the importance of high grid resolution 

      Pontoppidan, Marie; Reuder, Joachim; Mayer, Stephanie; Kolstad, Erik Wilhelm (Peer reviewed; Journal article, 2017)
      Floods due to intense rainfall are a major hazard to both people and infrastructure in western Norway. Here steep orography enhances precipitation and the complex terrain channels the runoff into narrow valleys and small ...
    • Downslope windstorm in Iceland –WRF/MM5 model comparison 

      Rögnvaldsson, Ólafur; Bao, J. W.; Ágústsson, Hálfdán; Ólafsson, Haraldur (Peer reviewed; Journal article, 2011-01-05)
      A severe windstorm downstream of Mt. Öræfajökull in Southeast Iceland is simulated on a grid of 1 km horizontal resolution by using the PSU/NCAR MM5 model and the Advanced Research WRF model. Both models are run with a ...
    • Drag coefficient reduction at very high wind speeds 

      Bye, John A. T.; Jenkins, Alastair D. (Peer reviewed; Journal article, 2006-03-31)
      The correct representation of the 10-m drag coefficient for momentum (K10) at extreme wind speeds is very important for modeling the development of tropical depressions and may also be relevant to the understanding of other ...
    • Drivers of the marine CO2 system in the High Arctic - from the deep basins to the shallow fjords 

      Ericson, Ylva (Doctoral thesis, 2019-02-20)
      The High Arctic is largely undersampled in terms of marine CO2 system data due to the cold dark season and often an extensive sea ice cover. The current understanding of the Arctic carbon cycle is thus vulnerable to both ...
    • Dual lidar wind measurements along an upstream horizontal line perpendicular to a suspension bridge 

      Nafisifard, Mohammad; Jakobsen, Jasna Bogunovic; Cheynet, Etienne; Snæbjörnsson, Jonas Thor; Sjöholm, Mikael; Mikkelsen, Torben (Journal article; Peer reviewed, 2021)
      Remote wind sensing can complement traditional anemometry at a bridge site and contribute to an improved wind-resistant design of long-span bridges. This study examines wind lidar measurement data recorded along a ...
    • Dual staining with CFDA-AM and SYTOX Blue in flow cytometry analysis of UV-irradiated Tetraselmis suecica to evaluate vitality 

      Olsen, Ranveig Ottøy; Hess-Erga, Ole-Kristian; Larsen, Aud; Hoffmann, Friederike; Thuestad, Gunnar; Hoell, Ingunn Alne (Peer reviewed; Journal article, 2016)
      After disinfection of ballast water, it is crucial to detect organisms and determine their vitality to assess the performance of the chosen treatment technique. Ultraviolet (UV) irradiation is a treatment technology commonly ...
    • The dynamic and thermodynamic structure of monsoon low-pressure systems during extreme rainfall events 

      Sørland, Silje Lund; Sorteberg, Asgeir (Peer reviewed; Journal article, 2015-08-12)
      A cyclone-tracking algorithm is used to identify monsoon low-pressure systems (LPS) in the ERA-interim re-analysis (1979–2010). The LPS that are connected to observed extreme rainfall events are picked out and studied with ...
    • Dynamic Modelling of Squirrel Cage Induction Motors for Studying Motor Current Signature Analysis 

      Askvik, Andreas (Master thesis, 2018-06-16)
      This study investigates dynamic modelling of induction motors with a variety of different defects and condition monitoring of these. The focus is directed at squirrel cage induction motors(SCIM) which is the most used ...
    • The dynamic response of offshore wind turbines and their sensitivity to wind field models 

      Haaskjold Myrtvedt, Maylinn; Nybø, Astrid; Nielsen, Finn Gunnar (Journal article; Peer reviewed, 2020)
      As the rotor diameter of offshore wind turbines increases, an improved understanding of the structure of the turbulent wind field approaching the rotor is important. Present standards for computing wind loads are resting ...
    • Dynamical controls on the longevity of a non-linear vortex : The case of the Lofoten Basin Eddy 

      Bosse, Anthony; Fer, Ilker; Lilly, Jonathan M.; Søiland, Henrik (Peer reviewed; Journal article, 2019-09-17)
      The Lofoten Basin is the largest oceanic reservoir of heat in the Nordic Seas, and the site of important heat fluxes to the atmosphere. An intense permanent anticyclone in the basin impacts the regional hydrography, ...
    • Dynamical downscaling of ERA-40 in complex terrain using the WRF regional climate model 

      Heikkilä, Ulla Elina; Sandvik, Anne Dagrun; Sorteberg, Asgeir (Peer reviewed; Journal article, 2010)
      Results from a first-time employment of the WRF regional climate model to climatological simulations in Europe are presented. The ERA-40 reanalysis (resolution 1 ) has been downscaled to a horizontal resolution of 30 and ...
    • Dynamical drivers of Greenland blocking in climate models 

      Michel, Clio; Madonna, Erica; Spensberger, Clemens; Li, Camille; Outten, Stephen (Journal article; Peer reviewed, 2021)
      Blocking over Greenland is known to lead to strong surface impacts, such as ice sheet melting, and a change in its future frequency can have important consequences. However, as previous studies demonstrated, climate models ...
    • Dynamical Perspectives on the Formation and Intensification of Polar Lows 

      Terpstra, Annick (Doctoral thesis, 2014-11-25)
      This thesis consists of a collection of scientific publications addressing dynamical aspects of the formation and intensification of polar lows. Polar lows are small scale, intense, short-lived cyclones developing over ...
    • A dynamical systems characterization of atmospheric jet regimes 

      Messori, Gabriele; Harnik, Nili; Madonna, Erica; Lachmy, Orli; Faranda, Davide (Journal article; Peer reviewed, 2021)
      Atmospheric jet streams are typically separated into primarily “eddy-driven” (or polar-front) jets and primarily “thermally driven” (or subtropical) jets. Some regions also display “merged” jets, resulting from the ...
    • Dynamically combining climate models to "supermodel" the tropical Pacific 

      Shen, Mao-Lin; Keenlyside, Noel; Selten, Frank; Wiegerinck, Wim; Duane, Gregory (Peer reviewed; Journal article, 2016-01)
      We construct an interactive ensemble of two different climate models to improve simulation of key aspects of tropical Pacific climate. Our so-called supermodel is based on two atmospheric general circulation models (AGCMs) ...
    • Dynamics and Predictability of the Extreme Extratropical Cyclone Nina 

      Selberg, Lars Andreas Norheim (Master thesis, 2016-06-01)
      An extreme extratropical cyclone struck western Norway at 12 UTC 10 January 2015 causing significant damage to property due to extreme winds. The European region has a history of being struck by extreme cyclones that cause ...
    • The dynamics of a barotropic current impinging on an ice front 

      Steiger, Nadine; Darelius, Elin Maria K.; Kimura, S; Patmore, Ryan Declan; Wåhlin, A. K. (Journal article; Peer reviewed, 2022)
      The vertical front of ice shelves represents a topographic barrier for barotropic currents that transport a considerable amount of heat toward the ice shelves. The blocking effect of the ice front on barotropic currents ...
    • Dynamics of a CO2-seawater interface in the deep ocean 

      Hove, Joakim; Haugan, Peter Mosby (Journal article, 2005)
      A trough filled with liquid CO2 located at 3940 m depth has been used as a model system for CO2 deposition on the seafloor. To study the intrinsic properties of the interface between CO2 and seawater a wave maker was used ...
    • Dynamics of anomalous stratospheric eddy heat flux events in an idealized model 

      Dunn-Sigouin, Etienne; Shaw, Tiffany (Journal article; Peer reviewed, 2020-05-28)
      Extreme stratospheric eddy and sudden stratospheric warming (SSW) events both involve anomalous stratospheric eddy heat flux. The cause of the anomaly has been hypothesized to be due to tropospheric or stratospheric dynamics. ...
    • Dynamics of concurrent and sequential Central European and Scandinavian heatwaves 

      Spensberger, Clemens; Madonna, Erica; Boettcher, Maxi; Grams, Christian M.; Papritz, Lukas; Quinting, Julian F.; Rothlisberger, Matthias; Sprenger, Michael; Zschenderlein, Philipp (Journal article; Peer reviewed, 2020)
      In both 2003 and 2018 a heatwave in Scandinavia in July was followed by a heatwave in Central Europe in August. Whereas the transition occurred abruptly in 2003, it was gradual in 2018 with a 12-day period of concurrent ...