Resources

Forecast

  • Sites are the points at which location-specific forecasts are available. Observations are the points with measured data from instruments.

  • Port site displays surge forecasting designed for specific ports.

  • Metocean data from forecast models and observations presented as map overlays. Metocean forecast layer show raw forecast model parameters.

    The images shown on the map correspond to the time selected in the map time control, as displayed at the top left of the map.

Hindcast

  • Ambient and extreme wind and wave summary statistics (monthly and annual).

  • A numerical model is used to generate the data. WW3 is typically used to create wave data globally or in large regions. Whereas SWAN generally is used to produce high-resolution wave data in small coastal areas.

MetOceanTrack

  • Display individual particle positions.

  • Display individual particle trajectories.

  • Display color-coded heatmap of current particle positions. A heatmap is a data visualization technique that shows magnitude of a phenomenon (here particle density) as colour in two dimensions.

  • Display color-coded heatmap of particle trajectories. A heatmap is a data visualization technique that shows magnitude of a phenomenon (here particle trajectories density) as colour in two dimensions.

  • Use the vertical current velocity from hydrodynamic model to move particles in the vertical direction (only available for 3D hydrodynamic models).

  • Mix particles vertically according to eddy diffusivity (i.e. turbulence) and buoyancy. Particle buoyancy is expressed as terminal velocity, which is the steady-state vertical velocity due to positive or negative buoyant behaviour. It is usually a function of particle density, diameter and shape as well as water density. Vertical particle displacement due to turbulent mixing is calculated using a random walk scheme (Visser et al. 1996) using user-defined or empirical vertical diffusivity profiles.

  • Time step used in the vertical mixing algorithm. The correct computation of the vertical mixing requires a timestep that is usually smaller (30-60 seconds) than usual tracking time steps (5-15 minutes) (see Visser et al. 1996).

  • Temperature and salinity data at particle positions are used to update the terminal velocity during the vertical mixing computations. For example, this is used to compute the sea water density in the pelagic plankton module, which in turn is used to compute particle terminal velocity.

  • Mix particles vertically according to eddy diffusivity and buoyancy .

  • Use surface Stokes drift velocity to advect particles. The Stokes drift velocity must be obtained from a wave model or using lookup tables based on wind speed.

  • Stokes drift is estimated from wind speed based on empirical look-up-tables for given fetch.

  • Wind drift is calculated using the relative wind, that is the wind vector minus ocean surface current vector.

  • Visser, A.: Using random walk models to simulate the vertical distribution of particles in a turbulent water column, Mar. Ecol.Prog. Ser., 158, 275–281, https://doi.org/10.3354/meps158275,1997.

Ocean models

  • Models are simplified representations of reality; they aim to describe and understand the main processes and drivers of whatever it is you are modelling – in this case the ocean. These models mimic how nature behaves by recreating those physical and natural processes and are then used to provide insight into an area of uncertainty.

  • ROMS is a 3D primitive equations ocean model using hydrostatic and Boussinesq approximations. Essentially, the model calculates the solutions for sea surface height, 3D currents and 3D temperature and salinity fields for the given forcing fields and boundary conditions. Forcing fields include, for instance, tides and atmospheric drivers, such as winds, sea level pressure and air-sea heat exchanges. The boundary conditions allows the model to receive information from another wider domain, coarser resolution model. The model terrain-following coordinate system is a benefit in regions of large bathymetry variations, solving all depth-dependent variables within the same number of vertical layers independently of the local depth.

  • SWAN is a third-generation ocean wave propagation model which solves the spectral action density balance equation (Booij et al., 1999). The model simulates the growth, refraction and decay of each frequency-direction component of the complete sea state, providing a realistic description of the wave field as it changes in time and space.

  • WAVEWATCH III® (Tolman 1997, 1999a, 2009) is a third-generation wave model developed at NOAA/NCEP in the spirit of the WAM model (WAMDIG 1988, Komen et al. 1994). It is a further development of the model WAVEWATCH, as developed at Delft University of Technology (Tolman 1989, 1991a) and WAVEWATCH II, developed at NASA, Goddard Space Flight Center (e.g., Tolman 1992). WAVEWATCH III®, however, differs from its predecessors in many important points such as the governing equations, the model structure, the numerical methods and the physical parameterizations. Furthermore, with model version 3.14, WAVEWATCH III® is evolving from a wave model into a wave modelling framework, which allows for easy development of additional physical and numerical approaches to wave modelling.

  • HyCOM is an open-source ocean general circulation modeling system. HyCOM is a primitive equation type of ocean general circulation model.