| UNCW
Mathematics Seminar |
Math Department Bear Hall 207 |
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A new formulation of a semi-implicit,
semi-Lagrangian
spectral method is given together with a conformal mapping of the
underlying
Gaussian grid. The mapping based on the
Schmidt transformation, focuses grid resolution on a particular region.
The
advective form of the vorticity-divergence equations allows the
conformal map
to be incorporated in a semi-Lagrangian transport step while
maintaining an efficient
spectral transform algorithm. The shallow water equations on the sphere
are
solved to test the variable resolution spectral model. By focusing on a
specified location local details of the flow are more accurately
resolved.
Accuracy and stability of the method are compared with uniform spectral
solutions.