Remote sensing and model simulation studies of the Norwegian coastal current during the algal bloom in May 1988

1989 ◽  
Vol 10 (12) ◽  
pp. 1893-1906 ◽  
Author(s):  
JOHNNY A. JOHANNESSEN ◽  
OLA M. JOHANNESSEN ◽  
PETER M. HAUGAN
Keyword(s):  
Remote Sensing ◽  
Algal Bloom ◽  
Model Simulation ◽  
Coastal Current ◽  
Simulation Studies ◽  
Norwegian Coastal Current

On the Variability in the Onset of the Norwegian Coastal Current

2018 ◽  
Vol 48 (3) ◽  
pp. 723-738 ◽  
Author(s):  
Kai Håkon Christensen ◽  
Ann Kristin Sperrevik ◽  
Göran Broström
Keyword(s):  
Remote Sensing ◽  
High Frequency ◽  
Conceptual Models ◽  
Sea Water ◽  
Surface Current ◽  
Wind Forcing ◽  
Coastal Current ◽  
Norwegian Coastal Current ◽  
Forcing Mechanisms

AbstractA high-resolution reanalysis of the circulation in the Kattegat and Skagerrak is used to investigate the mechanisms that control the variability in the onset of the Norwegian Coastal Current. In the reanalysis, the authors have used all available in situ and remote sensing observations of salinity and temperature and use surface current observations from two coastal high-frequency radars that were ideally placed to monitor the exchange between the two basins. This study finds a strong correlation between the variability in the wind forcing in the Skagerrak and the transport in the Norwegian Coastal Current through the Torungen–Hirtshals section. Two cases with winds into and out of the Skagerrak are studied in more detail, and the results suggest asymmetries in the forcing mechanisms. For winds out of the Skagerrak, strong outflows of Baltic Sea Water associated with a deflection of the Kattegat–Skagerrak Front may disrupt local processes in the Skagerrak, which is not accounted for in previously published conceptual models for the variability of the coastal currents in this region.

scholarly journals Modelling dispersal of eggs and quantifying connectivity among Norwegian coastal cod subpopulations

2013 ◽  
Vol 71 (4) ◽  
pp. 957-969 ◽  
Author(s):  
Mari S. Myksvoll ◽  
Kyung-Mi Jung ◽  
Jon Albretsen ◽  
Svein Sundby
Keyword(s):  
Ocean Model ◽  
Small Scale ◽  
Coastal Current ◽  
Life Stages ◽  
Early Life Stages ◽  
Dispersal Patterns ◽  
Norwegian Coast ◽  
Spawning Areas ◽  
Numerical Ocean Model ◽  
Norwegian Coastal Current

Abstract The Norwegian coast is populated by two cod populations: Northeast Arctic cod and Norwegian Coastal cod. In this paper, we use a further division based on life history: oceanic cod, coastal cod, and fjord cod. A numerical ocean model was implemented for the northern Norwegian coast where all these populations have spawning areas. The model results were used to simulate connectivity and retention of cod eggs from the different subpopulations. The model reproduced the observed variability and mesoscale activity in the Norwegian Coastal Current. Eggs released at an oceanic spawning area were transported northwards along the coastline. Coastal cod eggs had intermediate connectivity with each other and fjord cod eggs had high local retention. Although the high retention of eggs in fjord areas is mainly caused by a subsurface distribution of eggs, the intermediate retention of eggs from coastal spawning areas is caused by small-scale eddies in-between many small islands. The high-resolution ocean model made it possible to reveal these specific dispersal patterns. The high retention of early life stages in fjords combined with strong homing to spawning areas indicates that fjord subpopulations may be described as a metapopulation.

Whirls in the Norwegian Coastal Current

1983 ◽  
pp. 311-320 ◽  
Author(s):  
T. A. McClimans ◽  
J. H. Nilsen
Keyword(s):  
Coastal Current ◽  
Norwegian Coastal Current

scholarly journals Characteristics of the Norwegian Coastal Current during Years with High Recruitment of Norwegian Spring Spawning Herring (Clupea harengus L.)

PLoS ONE ◽  
2015 ◽  
Vol 10 (12) ◽  
pp. e0144117 ◽  
Author(s):  
Øystein Skagseth ◽  
Aril Slotte ◽  
Erling Kåre Stenevik ◽  
Richard D. M. Nash
Keyword(s):  
Clupea Harengus ◽  
Coastal Current ◽  
Norwegian Coastal Current ◽  
High Recruitment

The use of Cs and Sr isotopes as tracers in the Arctic Mediterranean Seas

1988 ◽  
Vol 325 (1583) ◽  
pp. 161-176 ◽  
Keyword(s):  
Deep Water ◽  
Thermohaline Circulation ◽  
Atlantic Water ◽  
The Arctic ◽  
Coastal Current ◽  
Intermediate Water ◽  
Sr Isotopes ◽  
Arctic Ice ◽  
Norwegian Coastal Current

The Arctic Mediterranean Seas constitute an oceanic region in which the thermohaline circulation has a strong advective component and deep ventilation processes are very active relative to other oceanic areas. Details of the nature of these circulation and ventilation processes have been revealed through use of Cs and Sr isotopes from bomb-fallout and nuclear-waste sources as ocean tracers. In both cases, their regional input is dominated by advective supply in the Norwegian Atlantic Current and Norwegian Coastal Current, respectively. The different temporal, spatial, and compositional input patterns of these tracers have been used to study different facets of the regional circulation. These input differences and some representative applications of the use of these tracers are reviewed. The data discussed derive from samples collected both from research vessels and from Arctic ice camps. The topics addressed include: ( a ) the role of Arctic Intermediate Water as source, supplying recent surface water to North Atlantic Deep Water via the Denmark Strait overflow; ( b ) deep convective mixing in the Greenland Sea; ( c ) circulation or recirculation of Atlantic water in the Arctic basins; and ( d ) the role of Arctic shelfwaters in the ventilation of intermediate and deep water in the Eurasian and Canadian basins.

Intercomparison of Phytoplankton functional types dynamics from satellite observations

2021 ◽  
Author(s):  
Marine Bretagnon ◽  
Séverine Alvain ◽  
Astrid Bracher ◽  
Philippe Garnesson ◽  
Svetlana losa ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Marine Environment ◽  
Model Simulation ◽  
Chlorophyll Concentration ◽  
Satellite Observations ◽  
Global Ocean ◽  
Ocean Colour ◽  
Marginal Seas ◽  
Functional Types ◽  
Wide Range

<p>Copernicus marine environment monitoring service (CMEMS) gives users access to a wide range of ocean descriptors. Both physics and biogeochemistry of the marine environment can be studied with complementary source of data, such as in situ data, modelling output and satellite observations at global scale and/or for European marginal seas. Among the ocean descriptors supplied as part of CMEMS, phytoplankton functional types (PFTs) describe the phytoplanktonic composition at global level or over European marginal seas. Studied phytoplankton assemblage is particularly important as it is the basis of the marine food-web. Composition of the first trophic level is a valuable indicator to infer the structure of the ecosystem and its health. Over the last decades, ocean colour remote sensing has been used to estimate the phytoplanktonic composition. The algorithms developed to estimate PFTs composition based on ocean colour observation can be classified in three categories: the spectral approaches, the abundance-based approaches (derived from the chlorophyll concentration) and the ecological approaches. The three approaches can lead to differences or, conversely, to similar patterns. Difference and similarity in PFTs estimation from remote sensing is a useful information for data assimilation or model simulation, as it provides indications on the uncertainties/variability associated to the PFT estimates. Indeed, PFT estimates from satellite observations are increasingly assimilated into ecological models to improve biogeochemical simulations, what highlights the importance to get an index or at least information describing the validity range of such PFTs estimates.</p><p>In this study, four algorithms (two abundance-based, and two spectral approaches) are compared. The aim of this study is to compare the related PFT products spatially and temporally, and to study the agreement of their derived PFT phenology. This study proposes also to compare PFT algorithms developed for the global ocean with those developed for specific regions in order to assess the potential strength and weakness of the different approaches. Once similarities and discrepancies between the different approaches are assessed, this information could be used by model to give an interval of confidence in model simulation.</p>

scholarly journals Dynamics and Patterning of Screw Dislocations in Two Dimensions

2000 ◽  
Vol 653 ◽  
Author(s):  
Robin L. B. Selinger ◽  
Brian B. Smith ◽  
Wei-Dong Luo
Keyword(s):  
Defect Density ◽  
Model Simulation ◽  
Two Dimensions ◽  
Xy Model ◽  
Shear Strain Rate ◽  
Simulation Studies ◽  
Ordered Structures ◽  
Screw Dislocations ◽  
Thermodynamic Forces ◽  
Computer Simulation Studies

AbstractTo understand how dislocations form ordered structures during the deformation of metals, we perform computer simulation studies of the dynamics and patterning of screw dislocations in two dimensions. The simulation is carried out using an idealized atomistic model with anti-plane displacements only; we show that this system is an analog of the two-dimensional XY rotor model. Simulation studies show that under a constant applied shear strain rate, the flow of dislocations spontaneously coalesces to form narrow dislocation-rich channels separated by wide dislocation-free regions, so that the applied strain is localized into slip bands. We argue that this pattern formation represents a phase separation into low/high defect density phases associated with the XY model, and conjecture that thermodynamic forces drive strain localization.

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