Experiments with a Self-Adaptive Multigrid Hurricane Track Model

                               Scott R. Fulton
                Department of Mathematics and Computer Science
                 Clarkson University, Potsdam, NY 13699--5815


                                   ABSTRACT

Accurate prediction of hurricane tracks may require resolving the flow both
within and around the storm.  Since the spatial scales in these two regions
differ substantially, uniform resolution is inherently inefficient:  the grid
should be refined only near the storm.

This paper describes and evaluates improvements to a hurricane track
prediction model (MUDBAR) described previously.  Based on the nondivergent
barotropic vorticity equation, this model uses an adaptive multigrid scheme to
automatically refine the mesh around the storm as it moves.  The original
model used grid patches of fixed size centered on the storm; we now introduce
a fully self-adaptive version, using estimates of the local truncation error
obtained during multigrid processing to control where to refine or coarsen the
grid.  Improvements to the time stepping algorithm and extension of the model
to spherical geometry will also be described.  Numerical results for a variety
of test cases show up to an order of magnitude improvement in efficiency over
that obtained on a uniform grid.


Scott R. Fulton
Department of Mathematics and Computer Science
Clarkson University
Campus Box 5815
Potsdam, NY 13699-5815
phone:   315-268-2379
FAX:     315-268-6670
email:   fulton@sun.mcs.clarkson.edu