Care has been taken to ensure that the model bathymetry is as realistic as the model resolution will permit. The links on this menu provide details of the bathymetry source datasets and the processing steps undertaken to derive the model bathymetry. After some initial trials it was decided that the coastlines obtained by the mapping method was too rough. In polar regions this can cause ice to pile-up against isolated headlands and creates excessive numbers of coastal points. The latter was of particular concern to the UKMO because the computation of fluxes in coastal zone gridcells is expensive. Early in 2008, Ian Culverwell of the UKMO produced a version with smoother coastlines and reintroduced a few missing landpoints such as the Galapogos Islands. This has now been adopted as the ORCA1 bathymetry for use with all vertical resolutions. The following four images show different views of this bathmetry held in the
bathy_meter_050308_UKMO.ncfile which can be obtained from the downloads page:
For those interested in viewing the changes, the equivalent unsmoothed images can be viewed using the links beneath each image.