ExnerFOAM, a semi-implicit model of the fully-compressible Euler equations, described in:
Curl free pressure gradients over orography in a solution of the fully compressibe Euler equations with implicit treatment of acoustic and gravity waves
Hilary Weller and Ava Shahrokhi
In prep for Monthly Weather Review

Download ExnerFoam

AtmosFOAM and Predicting Mesh Refinement
An example using adaptive mesh refinement: the barotropically unstable jet of Galewsky, Scott and Polvani (Tellus, 2004) run for 18 days.


The mesh adapts every 12 hours based on the combined vorticity and divergence gradients expected to appear over the following 12 hours. In order to calculate what we expect to appear we run a uniform coarse resolution model for 12 hours

The vorticity every three hours. The dots show the mesh cell centres. The vorticity at the same time but before and after each interpolation is shown. The coarse mesh run does not pick up everywhere with high vorticity gradients on the adapted mesh. This is probably a good thing: if we refine everywhere we find a high vorticity gradient we will end up refining everywhere. The coarse mesh run acts as a filter. And means that we do not have to adapt the mesh and interpolate so often. Also notice how new cells appear where they are about to be needed!

In order to run this code you must first install www.opencfd.co.uk

snapshot archive of source code on 32 Jan 2008
simple spherical geometry corrections
quadratic fit interpolation scheme
quadratic fit face gradient scheme

Last update: 23 Sept 2008