We explore the fundamental physics of narrow toroidal rings during their nonlinear magnetohydrodynamic evolution at tachocline depths. Using a shallow-water model, we simulate the nonlinear evolution of spot-producing toroidal rings of 6-degree latitudinal width and peak field of 15 kG.

We take a broad look at the problem of identifying the magnetic solar causes of space weather.

Dikpati, et. al., derive magnetic toroids from surface magnetograms by employing a novel optimization method based on Trust Region Reflective algorithm. Toroids obtained are combinations of Fourier modes (amplitudes and phases) with low longitudinal wavenumbers.

Evidence of the existence of hydrodynamic and MHD Rossby waves in the Sun is accumulating rapidly.

Rossby waves arise in thin layers within fluid regions of stars and planets. These global wave-like patterns occur due to the variation in Coriolis forces with latitude. In the past several years observational evidence has indicated that there are also Rossby waves in the Sun.

We demonstrate a novel physical mechanism, namely, that a “solar tsunami” occurring in the Sun’s interior shear-fluid layer can trigger new cycle’s magnetic flux emergence at high latitudes, a few weeks after the cessation of old cycle’s flux emergence near the equator.

Mausumi Dikpati presents a nonlinear magnetohydrodynamic shallow-water model for the solar tachocline (MHD-SWT) that generates quasi-periodic tachocline nonlinear oscillations (TNOs) that can be identified with the recently discovered solar 'seasons'.