The HyperCASL algorithm

  • David G. Dritschel
  • Jérôme Fontane
Part of the IUTAM Bookseries book series (IUTAMBOOK, volume 28)


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.


Potential Vorticity Point Vortex Grid Length Contour Dynamic Node Separation 
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© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  1. 1.Mathematical InstituteUniversity of St AndrewsSt AndrewsScotland

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