Hello, I recently posted a video on youtube that shows the evolution of the perturbation Potential Vorticity for a Gaussian vortex. Initially you see a tripole structure and then a mode 2 structure that is well predicted by the linear theory. This is all done using the QG firedrake code that we've been developing. https://youtu.be/6YLPT7glvlU One thing that is less than ideal is that I am using white noise for the initial perturbations. Someone mentioned that I should probably solve the Poisson problem where white noise is the RHS, and that should clean things up. I will try and do that but it seems that early on, even after the perturbations establish themselves you can still see the grid. In this case I am using a 400x400 rectangular grid. Do people think that an unstructured mesh might make the grid less apparent? Maybe part of the problem is with how it's being plotted in VisIt, I'm not sure but I thought I would ask people's advice. Cheers, Francis ------------------ Francis Poulin Associate Professor Department of Applied Mathematics University of Waterloo email: fpoulin@uwaterloo.ca Web: https://uwaterloo.ca/poulin-research-group/ Telephone: +1 519 888 4567 x32637