Numerical modelling of physical processes governing larval transport in the southern North Sea
Tiessen, M.C.H.; Fernand, L.; Gerkema, T.; van der Molen, J.; Ruardij, P.; van der Veer, H.W. (2014). Numerical modelling of physical processes governing larval transport in the southern North Sea. Ocean Sci. 10: 357-376. http://dx.doi.org/10.5194/os-10-357-2014
In: Ocean Science. Copernicus: Göttingen. ISSN 1812-0784; e-ISSN 1812-0792, meer
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| Auteurs | | Top |
- Tiessen, M.C.H., meer
- Fernand, L.
- Gerkema, T., meer
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- van der Molen, J.
- Ruardij, P., meer
- van der Veer, H.W., meer
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| Abstract |
A three-dimensional hydrodynamic model(GETM) was coupled with a particle tracking routine(GITM) to study the inter-annual variability in transportpaths of particles in the North Sea and English Channel. Forvalidation, a comparison with observed drifter trajectoriesis also presented here. This research investigated to whatextent variability in the hydrodynamic conditions alone(reflecting passive particle transport) contributed to interannualvariability in the transport of eggs and larvae. In thisidealised study, no a priori selection of specific spawninggrounds or periods was made and no active behaviour(vertical migration) or mortality was included. In this study,egg and larval development towards coastal nursery areaswas based solely on sea water temperature, while settlementareas were defined by a threshold water depth. Resultsshowed strong inter-annual variability in drift directionand distance, caused by a combination of wind speed anddirection. Strong inter-annual variability was observed bothin absolute amount of settlement in several coastal areas, andin the relative importance of the different areas. The effectsof wind and temperature variability are minor for settlementalong the western shores of the North Sea and in the EnglishChannel, but have a very significant impact on settlementalong the eastern shores of the North Sea. Years with strongsouth-westerly winds across the Dover Straight resultedin higher settlement figures along its eastern shores of theNorth Sea (standard deviation 37% of the mean annualsettlement value). Settlement in the western Dutch WaddenSea did not only show inter-annual variability, but patternswere also variable within each year and revealed seasonalchanges in the origin of particles: during winter, strongercurrents along with colder temperatures generally result inparticles originating from further away. |
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