Description
In the equatorial region of the stellar convection zone, rotating convection tends to form vortical columns that propagate in a prograde direction. These convective columns are often called “banana cells” or “thermal Rossby waves.” In numerical simulations, they are commonly observed and found to play a significant role in transporting angular momentum, driving solar-like differential rotation. However, they have never been successfully observed in solar surface observations. Bridging this gap between numerical simulations and solar observations remains an open challenge. A physical ingredient likely missing in most numerical models is small-scale dynamo, which is believed to operate vigorously in the Sun and stars but is very costly to resolve numerically. In this talk, we report a series of high-resolution numerical simulations of rotating magneto-convection using a local f-plane box at the equator with varying Rossby numbers. We find that with the presence of small-scale dynamo, thermal Rossby waves have smaller amplitudes and higher longitudinal wavenumbers. We also find that the generation of mean zonal flow is significantly suppressed by the small-scale dynamo, as the Maxwell stresses counteract the Reynolds stresses. Finally, we will briefly discuss possible implications for the convective conundrum.
