FlexSemFlexSemAarhus University department of Ecoscience

Aalborg Bugt

The Aalborg Bugt setup is a hydrostatic hydrodynamic model for Kattegat. The unstructured computational mesh has open boundaries in the north towards Skagerrak and the North Sea, in the south east at Øresund and in the south west toward Samsø Bælt. The mesh consist of 2840 polygons with a resolution of 200m in Aalborg bugt and a lower resolution of 4.5 km toward Sweden. The model implements 20 vertical z-layers ranging in thickness from 2m in the top 10 layers to 10 meters in the bottom layers. Bathymetry was interpolated from a 50 meter gridded bathymetry provide by the Danish Cadastre. Open boundary forcings of water level, temperature, salinity and velocities was interpolated from data downloaded from Copernicus Marine Environment Monitoring Service (CMEMS) and ajusted with measured data from the Danish Monitoring Programme. Meteorological forcing data of wind velocities, temperature, dew point temperature, cloud cover and precipitation was downloaded from the Copernicus ERA5 hourly data. 14 fresh sources adds fresh water to the model. The model was run for the years 2017, 2018 and 2019, each year initialized with temperature and salinity values from the Copernicus data.
This model is currently being used for the dispersal of eelgrass (Zostera marina) in the area. The dispersal is being simulated with a Lagrangian Individual Based Model (IBM) implemented in the FlexSem framework. Particles represent suspended seeds with a short dispersal phase and reproductive shoots with a longer dispersal phase. Both seeds and shoots are positively buoyant and particles in the model drift in the surface. The connectivity of eelgrass in this area will be analyzed from the model outputs. In addition, centrality measures will be calculated to understand the effect of the connectivity derived from potential and realized larval connectivity networks.