  The magnetic switchbacks observed recently by the Parker Solar Probe have
raised the question about their nature and origin. One of the competing
theories of their origin is the interchange reconnection in the solar corona.
In this scenario, switchbacks are generated at the reconnection site between
open and closed magnetic fields, and are either advected by an upflow or
propagate as waves into the solar wind. In this paper we test the wave
hypothesis, numerically modelling the propagation of a switchback, modelled as
an embedded Alfv\'en wave packet of constant magnetic field magnitude, through
the gravitationally stratified solar corona with different degrees of
background magnetic field expansion. While switchbacks propagating in a uniform
medium with no gravity are relatively stable, as reported previously, we find
that gravitational stratification together with the expansion of the magnetic
field act in multiple ways to deform the switchbacks. These include WKB
effects, which depend on the degree of magnetic field expansion, and also
finite-amplitude effects, such as the symmetry breaking between nonlinear
advection and the Lorentz force. In a straight or radially expanding magnetic
field the propagating switchbacks unfold into waves that cause minimal magnetic
field deflections, while a super-radially expanding magnetic field aids in
maintaining strong deflections. Other important effects are the mass uplift the
propagating switchbacks induce and the reconnection and drainage of plasmoids
contained within the switchbacks. In the Appendix, we examine a series of
setups with different switchback configurations and parameters, which broaden
the scope of our study.
