- Letter
Rapidly rotating self-gravitating Boussinesq fluid. III. A previously unknown zonal oscillation at the onset of rotating convection
Phys. Rev. Fluids 8, L011501 – Published 30 January, 2023
DOI: https://doi.org/10.1103/PhysRevFluids.8.L011501
Abstract
Realistic rotating fluid under self-gravitation will be oblate due to the centrifugal force. In our previous paper [Li and Kong, Phys. Rev. Fluids 7, 103502 (2022)], for the first time, the problem of convective instabilities was formulated and tackled in rotationally flattened spheroids. Using that method, this paper demonstrates how extraordinary nonsphericity alters the linear onset of thermal inertial convection in internally heated Boussinesq fluid. A significant discovery is that the globally most unstable mode could switch from a non-axisymmetric quasigeostrophic wave to an equatorially symmetric zonal oscillation when the rotational flattening effect gets very strong. This was the only form of global convection not found so far.
