Lessons from Numerics

• 1) Use as low a dimension as possible. “As simple as possible, but no simpler.”

• 2) Use as analytic a technique as possible.

• Example: Radiation Belt Models.

  • 3-D, averaging over Fm,FJ,FL
  • symmetry in B, allows L = radial distance,
  • thus diffusion in L is separable from convection

• Extension to Ring Current Belt Models?

  • NOT SYMMETRIC! Drift shell splitting, ...
  • NOT SEPARABLE!