Browsing Bergen Open Research Archive by Author "Sperrevik, Ann Kristin"
Now showing items 1-5 of 5
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Constraining energetic slope currents through assimilation of high-frequency radar observations
Sperrevik, Ann Kristin; Christensen, Kai Håkon; Röhrs, Johannes (Peer reviewed; Journal article, 2015-03-11)Assimilation of high-frequency (HF) radar current observations and CTD hydrography is performed with the 4D-Var analysis scheme implemented in the Regional Ocean Modeling System (ROMS). We consider both an idealized case, ... -
Impact of data assimilation on Eulerian versus Lagrangian estimates of upper ocean transport
Sperrevik, Ann Kristin; Röhrs, Johannes; Christensen, Kai Håkon (Peer reviewed; Journal article, 2017)Using four-dimensional variational analysis, we produce an estimate of the state of a coastal region in Northern Norway during the late winter and spring in 1984. We use satellite sea surface temperature and in situ ... -
Modeling coastal circulation in Norway using a high-resolution 4D-Var ocean assimilation system
Sperrevik, Ann Kristin (Doctoral thesis, 2017-06-23)The circulation along the Norwegian coast is characterized by many transient smallscale features such as eddies and meanders that are challenging to reproduce by means of numerical modeling. In this thesis I investigate ... -
Sub-surface maxima in buoyant fish eggs indicate vertical velocity shear and spatially limited spawning grounds
Strand, Kjersti Opstad; Vikebø, Frode; Sundby, Svein; Sperrevik, Ann Kristin (Peer reviewed; Journal article, 2018)Observed vertical profiles of buoyant particles, in this case pelagic Northeast Arctic cod eggs, occasionally deviate from the vertical diffusion-buoyancy balance by displaying sub-surface maxima. Here we present a mechanism ... -
Subsurface maxima in buoyant fish eggs indicate vertical velocity shearand spatially limited spawning grounds
Strand, Kjersti Opstad; Vikebø, Frode Bendiksen; Sundby, Svein; Sperrevik, Ann Kristin; Breivik, Øyvind (Peer reviewed; Journal article, 2019-05)Observed vertical profiles of buoyant particles, in this case pelagic Northeast Arctic (NEA) cod eggs, occasionally deviate from the vertical diffusion‐buoyancy balance by displaying subsurface maxima. Here, we present a ...