  Operating experience from fusion research shows how Spitzer resistivity may
render ohmic heating in the chromosphere self limiting and thus serve to define
the lower margin of the transition region. Its upper margin is at about 6000 K,
where radiative cooling of He:H plasma decelerates sharply. The third and last
stage in the proposed scheme is expansion into the tenuous plasma of space,
which leads to the acceleration of ions to high energies, long recorded by
spacecraft instruments. There is thus dynamic continuity all the way from the
solar interior, the energy source for spinning columns in the Rayleigh Benard
setting of the convection zone, to the coronal exhalation of the solar wind, a
finding which should benefit the analysis of space weather, witness the
association between helium in the solar wind and the incidence of coronal mass
ejections.
