A fairly simple idea, really.
When you look at the weather processes on earth, they are substantially circular. Equatorial winds circle the globe. Hadley cells are rolling cylinders. From tornados to hurricanes to high or low pressure cells, winds turn in circles. Polar vortex rotates about the poles, as does the polar night jet.
Yet the climate models are based on grids of square cells. Admittedly bent over a spherical surface in model terms, sort of.
So just how do you properly model a fundamentally circular, cylindrical, spherical process with little square blocks? Winds from one cell into the next cell over will be leaving on a flat parallel face, not with a vector at an angle. I suppose you could have a vector inside the square cell, but even then the mass must move in the square grid.
It seems to me this is fitting a round peg in a square hole and not going to work particularly well.
Pondering this, I thought of a hexagonal grid. Not perfect, but at least then mass can flow in a direction other than 90 degrees. A series of 60 degree changes gives you a hexagonal flow. Not circular, but at least not a straight line.
For 3D space filling, the tetrahedral octahedral honeycomb works.
I know it would tend to complicate how you think about programming the problem, but it just intuitively feels like a better approximation of the real circular processes to have vectors to adjoining cells other than 90 degrees.
Ideas? Speculation? Rock tossing?