  Coronal-hole jets occur ubiquitously in solar coronal holes, at EUV and X-ray
bright points associated with intrusions of minority magnetic polarity. The
embedded-bipole model for these jets posits that they are driven by explosive,
fast reconnection between the stressed closed field of the embedded bipole and
the open field of the surrounding coronal hole. Previous numerical studies in
Cartesian geometry, assuming uniform ambient magnetic field and plasma while
neglecting gravity and solar wind, demonstrated that the model is robust and
can produce jet-like events in simple configurations. We have extended these
investigations by including spherical geometry, gravity, and solar wind in a
nonuniform, coronal hole-like ambient atmosphere. Our simulations confirm that
the jet is initiated by the onset of a kink-like instability of the internal
closed field, which induces a burst of reconnection between the closed and
external open field, launching a helical jet. Our new results demonstrate that
the jet propagation is sustained through the outer corona, in the form of a
traveling nonlinear Alfven wave front trailed by slower-moving plasma density
enhancements that are compressed and accelerated by the wave. This finding
agrees well with observations of white-light coronal-hole jets, and can explain
microstreams and torsional Alfven waves detected in situ in the solar wind. We
also use our numerical results to deduce scaling relationships between
properties of the coronal source region and the characteristics of the
resulting jet, which can be tested against observations.
