NOCS ORCA1 home page

The NOCS ORCA1 home page

Source data for the ORCA1 model bathymetry

The model bathymetry is derived from a slightly modified version of the ETOPO2 2 minute global bathymetry. This dataset was compiled from a montage of Sandwell and Smith satellite derived values (+/-72° ), IBCAO values in the Arctic and DBDB5 values south of 72° S. Full references are provided on the link above. The weakest part of this compilation is the DBDB5 dataset which was assembled by the US Naval Oceanographic Office in the early 1980's from computer interpolation of existing contour maps of ocean basins. Several projects over the last decades have mapped the bathymetry of the Southern Ocean in greater detail and some of the more recent gridded products were patched into our local version of the etopo2 bathymetry before the ORCA1 bathymetry was derived.

These products were taken from the Antarctic Barotropic Tide Models produced by the Seattle based Earth and Space Research Institute ( ESR). The bathymetric data provided with the following models:

were patched into the etopo2 dataset. The two high resolution regional sets simply replaced existing values in those regions. The circum-Antarctic set was only applied along the shelf region ( H < 1200m ) because of its relatively crude longitudinal resolution.

The resulting modified etopo2 dataset is available from our ftp server (in NetCDF):

FTP link:

NOCS modified ETOPO2 Global Bathymetry (netcdf)