  Dust Dynamics Simulations utilizing a dynamical screening approach are
performed to study the effect of ion-streaming on the self-organized structures
in a three-dimensional spherically confined complex (dusty) plasma. Varying the
Mach number M - the ratio of ion drift velocity to the sound velocity, the
simulations reproduce the experimentally observed cluster configurations in the
two limiting cases: at M=0 strongly correlated crystalline structures
consisting of nested spherical shells (Yukawa balls) and, for M\geq1,
flow-aligned dust chains, respectively. In addition, our simulations reveal a
discontinuous transition between these two limits. It is found that already a
moderate ion drift velocity (M\approx0.1) destabilizes the highly ordered
Yukawa balls and initiates an abrupt melting transition. The critical value of
M is found to be independent of the cluster size.
