Hierarchy of the characteristic angular frequencies hypothesised in this work. The quantities related to the envelope are specified in the top panel, while the quantities related to the core are noted in the bottom panel. Values for the linear frequencies for the fz model are denoted in parentheses. An Alfvén frequency of ${\omega }_{\mathrm{A},\mathrm{env}}\approx 5\times {10}^{-2}\mu \mathrm{Hz}$ corresponds to an equatorial field strength of ${\mathrm{B}}_0^{\phi }\approx 9\times {10}^4\mathrm{G}$ at the bottom of the radiative zone for the three considered models.