2023-03-22T19:23:17Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/697662022-11-17T02:08:08Zhdl_2115_45007hdl_2115_116Oscillatory damping in long-time evolution of the surface quasi-geostrophic equations with generalised viscosity: a numerical studyOhkitani, KojiSakajo, Takashi410We study numerically the long-time evolution of the surface quasi-geostrophic equation with generalised viscosity of the form $(-¥Delta)^¥alpha$, where global regularity has been proved mathematically for the subcritical parameter range $¥alpha ¥geq ¥frac{1}{2}$. Even in the supercritical range, we have found numerically that smooth evolution persists, but with a very slow and oscillatory damping in the long run. A subtle balance between nonlinear and dissipative terms is observed therein. Notably, qualitative behaviours of the analytic properties of the solution do not change in the super and subcritical ranges, suggesting the current theoretical boundary $¥alpha =¥frac{1}{2}$ is of technical nature.Department of Mathematics, Hokkaido UniversityDepartmental Bulletin Paperapplication/pdfhttp://hdl.handle.net/2115/69766info:doi/10.14943/84106https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/69766/1/pre959.pdfHokkaido University Preprint Series in Mathematics95912010-05-01engpublisher