Proper motions, flux and polarization variability from a parsec scale blazar monitoring program

Abstract We review the results from a polarization sensitive, six-epoch (at about 2 month intervals), dual frequency (22 and 15 GHz) VLBA program that monitored rapid changes in the structure and polarization of 12 highly active AGN jets. Our analysis of the proper motion, polarization and flux variability of VLBI ‘components’, is in the context of some key questions addressed at this meeting including, dependence of jet velocities on distance from nucleus, structure and evolution of jet magnetic fields and jet morphology.