  have forced the definition of a new type of spicule, "type II's", that are
characterized by rising rapidly, having short lives, and by fading away at the
end of their lifetimes. Here, we report on features found in realistic 3D
simulations of the outer solar atmosphere that resemble the observed type II
spicules. These features evolve naturally from the simulations as a consequence
of the magnetohydrodynamical evolution of the model atmosphere. The simulations
span from the upper layer of the convection zone to the lower corona and
include the emergence of horizontal magnetic flux. The state-of-art Oslo
Staggered Code (OSC) is used to solve the full MHD equations with non-grey and
non-LTE radiative transfer and thermal conduction along the magnetic field
lines. We describe in detail the physics involved in a process which we
consider a possible candidate as a driver mechanism to produce type II
spicules. The modeled spicule is composed of material rapidly ejected from the
chromosphere that rises into the corona while being heated. Its source lies in
a region with large field gradients and intense electric currents, which lead
to a strong Lorentz force that squeezes the chromospheric material, resulting
in a vertical pressure gradient that propels the spicule along the magnetic
field, as well as Joule heating, which heats the the jet material, forcing it
to fade.
