A movie of the superfluid condensate |<psi(t,x)>|^2 as it evolves from time t = 0 to t = 300.  Blue indicates zero condensate.   The condensate vanishes at the core of each vortex.  The initial conditions involve a lattice of winding number +6 and -6 vortices.  As the system evolves, the winding number 6 vortices rapidly decay into 6 winding number 1 vortices, which have much smaller cores.  Vortex annihilation then proceeds as soon as individual vortices from neighboring lattice sites find each other.  Large quasi-solitonic waves spread away form each annihilation event.