  Two of the most widely observed and yet most puzzling features of the Sun's
magnetic field are coronal loops that are smooth and laminar and
prominences/filaments that are strongly sheared. These two features would seem
to be quite unrelated in that the loops are near their minimum-energy
current-free state, whereas filaments are regions of high magnetic stress and
intense electric currents. We argue that, in fact, these two features are
inextricably linked in that both are due to a single process: the injection of
magnetic helicity into the corona by photospheric motions and the subsequent
evolution of this helicity by coronal reconnection. In this paper, we present
numerical simulations of the response of a \citet{Parker72} corona to
photospheric driving motions that have varying degrees of helicity preference.
We obtain four main conclusions: 1) in agreement with the helicity condensation
model of \citet{Antiochos13}, the inverse cascade of helicity by magnetic
reconnection results in the formation of prominences/filaments localized about
polarity inversion lines (PILs); 2) this same process removes most structure
from the rest of the corona, resulting in smooth and laminar coronal loops; 3)
the amount of remnant tangling in coronal loops is inversely dependent on the
net helicity injected by the driving motions; and 4) the structure of the solar
corona depends only on the helicity preference of the driving motions and not
on their detailed time dependence. We discuss the implications of our results
for high-resolution observations of the corona.
