The flux-surface integrated poloidal and toroidal electromagnetic torque densities acting on the plasma can be written
respectively. Equations (14.3), (14.8), (14.9), (14.44), and (14.58)–(14.60) yield
Let

Note that these quantities are, in general, complex.
It follows that [11,14,16]
where
It can be seen, by analogy with the analysis of Sections 3.3, 3.8, and 3.13, that
is the reconnected magnetic flux at the
th rational surface, whereas
parameterizes the amplitude and phase of the current sheet flowing (parallel to the equilibrium
magnetic field) at the same surface.