Influence of a magnetic narrow region on the propagation of Type II spicules into the solar corona

In this paper, we study the possible influence of a magnetic narrow region
on the propagation of jets with some characteristics of Type II spicules
into the solar corona using two approximations: thermo-mechanical (TM) and
magnetohydrodynamic (MHD). We motivate the idea of this paper by
considering that some advanced 2.5D numerical simulations of radiation MHD
of the formation of Type II spicules show the narrowing of the magnetic
field lines in the loops where the spicules propagate. In particular, we
propose that the magnetic narrow region be described in terms of a
magnetic bottle configuration. In the TM approximation, we have found that
the magnetic bottle produces that the 9% of the plasma embedded manages to
escape the magnetic confinement, in contrast, the remaining 91% returns to
the bottom of configuration colliding to the raising plasma and generating
a heating process. The heating process could represent a source that
maintains the current temperature of the corona. On the other hand, in the
MHD approximation, through numerical simulations, we found that it occurs
an increase of temperature mainly at the top of the jet, which supports
the idea of sectioning the spicule in the TM approximation. Also, in the
MHD approximation, we show that the magnetic bottle does not directly
affect the propagation of the jet; since the physical conditions of the
ideal MHD equations imply that the magnetic field lines are frozen-in with
the plasma, and no confinement effect is possible.