They say (in popular videos and articles) that tangled magnetic fields on Sun explode. But i don't understand why and how magnetic fields, tangled or not, explode. Could anyone explain?

I understand that we can use the Heisenberg picture to show, for a Hamiltonian of the form $$ \hat{H}=\frac{\hat{P}^{2}}{2m}+\hat{V}(\hat{X}) $$ the Ehrenfest theorem: $$ m\partial_{t}\langle \hat{X}\rangle=\langle \hat{P}\rangle\ \text{ and } \partial_{t}\langle \hat{P}\rangle=-\langle \hat{...