  We analyze high resolution simulations of compressible, MHD turbulence with
properties resembling conditions in galaxy clusters. The flow is driven to
turbulence Mach number $\mathcal{M}_t \sim 1/2$ in an isothermal medium with an
initially very weak, uniform seed magnetic field ($\beta = P_g/P_B = 10^6$).
Since cluster turbulence is likely to result from a mix of sheared (solenoidal)
and compressive forcing processes, we examine the distinct turbulence
properties for both cases. In one set of simulations velocity forcing is
entirely solenoidal ($\nabla\cdot \delta {\vec u} = 0$), while in the other it
is entirely compressive ($\nabla\times \delta {\vec u} = 0$). Both cases
develop a mixture of solenoidal and compressive turbulent motions, since each
generates the other. The development of compressive turbulent motions leads to
shocks, even when the turbulence is solenoidally forced and subsonic. Shocks,
in turn, produce and amplify vorticity, which is especially important in
compressively forced turbulence. To clarify those processes we include a pair
of appendices that look in detail at vorticity evolution in association with
shocks. From our simulation analyses we find that magnetic fields amplified to
near saturation levels in predominantly solenoidal turbulence can actually
enhance vorticity on small scales by concentrating and stabilizing shear. The
properties, evolution rates and relative contributions of the kinetic and
magnetic turbulent elements depend strongly on the character of the forcing.
Specifically, shocks are stronger, but vorticity evolution and magnetic field
amplification are slower and weaker when the turbulence is compressively
forced. We identify a simple relation to estimate characteristic shock
strengths in terms of the turbulence Mach number and the character of the
forcing. Our results will be helpful in understanding flow motions in galaxy
clusters.
