The HyperCASL algorithm
This paper outlines a major new extension to the diabatic Contour-Advective Semi-Lagrangian (CASL) algorithm (Dritschel and Ambaum, 1997, 2006). The extension, called the ‘HyperCASL’ (HCASL) algorithm, advects material potential vorticity contours like in CASL, but treats diabatic forcing or damping with a Vortex-In-Cell (VIC) algorithm. As a result, HCASL is fully Lagrangian regarding advection. A conventional underlying grid is used as in CASL for ‘inversion’, namely for obtaining the advecting velocity from the potential vorticity.
KeywordsPotential Vorticity Point Vortex Grid Length Contour Dynamic Node Separation
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