Simulation of a perfect fluid on the sphere using
QUFLOW.
The evolution of the vorticity field using the Hammer geographical
projection of the sphere is shown. After an initial phase of weak
mixing, four vortex blobs appear. The research hypothesis is that thesefour blobs correspond to the largest number N of point vortices for
which the dynamics is integrable: for the sphere with vanishing angular
momentum this is N = 4.