  We investigate the nonlinear effects of uniform rotation on the Parker
instability in an exponentially-stratified disk through high-resolution
simulations. During the linear stage, the speed of gas motion is subsonic and
the evolution with the rotation is not much different from that without the
rotation. This is because the Coriolis force is small. During the nonlinear
stage, oppositely-directed supersonic flows near a magnetic valley are under
the influence of the Coriolis force with different directions, resulting in
twisted magnetic field lines near the valley. Sheet-like structures, which are
tilted with respect to the initial field direction, are formed with an 1.5
enhancement of column density with respect to its initial value. Even though
uniform rotation doesn't give much impact on density enhancement, it generates
helically twisted field lines, which may become an additional support mechanism
of clouds.
