Die Kuste, 81 (2014), 255-271 
269 
4 Concluding remarks and perspectives 
In this paper die application of the Lagrangian drift model SeatrackWeb to two real cases 
is presented. In die first case die drift of heavy oil in die Skagerrak released during die 
average of die “Full City” tanker in 2009 is simulated. The reported and simulated beach- 
ings are quite consistent. The other case dealt widi the drift forecast of objects, namely 
containers. The results showed reasonably good agreement with observation considering 
the uncertainties of the weather model and the resolution of the ocean model. We identi 
fied that differences in swell and wind direction lead to errors in the drift forecast. Since 
the wave induced displacement is computed using die so called Stokes drift, which is pa 
rameterized by die wind, tiiis component could be improved by directly using die Stokes 
drift from an operational wave model. The BSH has already access to wave model results 
of WAM (WAMDI 1988) run by die German Weather Service (DWD). In future the 
Stokes drift could be included in the wave model result files and SeatrackWeb could read 
in die Stokes drift velocities instead of computing it internally in the parametrized wave 
model of PADM. As a side effect die computing time of die drift simulation would also 
be reduced. 
Concerning PADM the horizontal spreading of objects and oil is still an ongoing field 
of research. For example die influence of unresolved eddies, Langmuir circulations and 
gusts is an unsolved problem. These processes may increase the spreading. Also die 
thickening of oil in downwind direction and tar ball formation is not yet fully solved in 
SeatrackWeb. 
Anotiier factor for accurate results is die performance of meteorological and ocean 
models. BSHcmod runs only once a day due to limitations of computer resources, so die 
latest meteorological forcing is not used. In general die forecast quality of ocean models 
improves witii die more recent wind forcing. The development of a modernized version 
of BSHcmod (so called HBM, see article in diis journal) aims to have a faster model code 
suitable for modern, parallelized computer architectures. If die validation shows that the 
predicted currents are of the same or even better quality and HBM can run several times 
a day, the drift model forecasts will improve. Changing to HBM would only require small 
changes in die SeatrackWeb routines for reading and producing die setup and forcing 
files. Furdiermore, HBM is already applied to die Elbe estuary. Including Elbe forcing as 
a further nesting level in SeatrackWeb will give finer resolved currents for die Elbe and 
would dierefore increase die drift forecast quality in this region. 
In case of oil spills the Central Command for Emergencies may choose for example 
dispersants and booms for oil combatting at sea. Applying dispersants changes the trajec 
tory of the oil pollution, since the oil disperses in the water column having different cur 
rents and no direct wind drag. Any means of combatting oil will have to fulfill die condi 
tion that die intervention leads to less negative consequences than witiiout. Where die oil 
or oil dispersant mixture will drift is very important information. To give predictions of 
the oil dispersant mixture is not yet possible in SeatrackWeb, but ongoing development 
togetiier witii Helmholtz-Zentrum Geesthacht (HZG). 
Anotiier important means for combatting oil at sea are booms. Booms keep oil in an 
area, prevent furdier spreading and facilitate oil recovery. SMHI currently sets a new ver 
sion of die GUI in operation, where it is possible to simulate the application of booms. It 
is possible to estimate how much oil is trapped by each boom, which facilitates finding