Advanced Ocean Modelling: Using Open-Source Software

134 5 3D Level ModellingFig. 5.6 An ocean eddy of about 20 km in radius. The spirals are ice bands. The photo was takenfrom an airplane flying over the Sea of Okhotsk. From Wakasutchi and Ohshima (1990)regions of cold winter climates and sea ice formation, the trace of eddies can producespectacular and beautiful patterns in the sea ice, such as in the Sea of Okhotsk(Fig. 5.6).Narrow passages connecting ocean basins are called straits. Straits are oftencombined with shallower water depth associated with a sill. The Soya Warm Currententers the Sea of Okhotsk from the Sea of Japan through the Soja Strait andcontinues along the coast of Hokkaido as a coastal boundary current. Instability ofthis coastal current produces spiralling ice patterns which are akin to cloud patternsproduced by hurricanes.5.4.2 AimThe aim of this exercise is to simulate eddy shedding of the Soya Warm Current inthe Sea of Okhotsk with the three-dimensional hydrodynamic model developed inthis book. To this end, an experimental design similar to that used by Ohshima andWakatsuchi (1990) in their numerical study will be employed.5.4.3 Task DescriptionThis exercise requires variable bathymetry resembling that of the Sea of Okhotsk.One option would be to download realistic gridded bathymetric data from the Inter-