Combined Surface Flux Transport and Helioseismic Far-Side Active Region Model (FARM).

Maps of the magnetic field at the Sun's surface are commonly used as boundary conditions in space-weather modeling. However, continuous observations are only available from the Earth-facing part of the Sun's surface. One commonly used approach to mitigate the lack of far-side information is to apply a surface flux transport (SFT) model to model the evolution of the magnetic field as the Sun rotates.

The Sun's differential rotation is controlled by high-latitude baroclinically unstable inertial modes.

Rapidly rotating fluids have a rotation profile that depends only on the distance from the rotation axis, in accordance with the Taylor-Proudman theorem. Although the Sun was expected to be such a body, helioseismology showed that the rotation rate in the convection zone is closer to constant on radii. It has been postulated that this deviation is due to the poles being warmer than the equator by a few degrees.

Meridional flow in the Sun's convection zone is a single cell in each hemisphere.

The Sun's magnetic field is generated by subsurface motions of the convecting plasma. The latitude at which the magnetic field emerges through the solar surface (as sunspots) drifts toward the equator over the course of the 11-year solar cycle. We use helioseismology to infer the meridional flow (in the latitudinal and radial directions) over two solar cycles covering 1996-2019.

The Sun is less active than other solar-like stars.

The magnetic activity of the Sun and other stars causes their brightness to vary. We investigated how typical the Sun's variability is compared with other solar-like stars, i.e.