This figure highlights the clockwise rotation in the ridge, and the counterclockwise rotation in the trough.  Areas of upper divergence are normally found on the backside of a ridge, and on the forward side of a trough, while upper convergence is normally found on the backside of a trough and on the forward side of a ridge.  However, this is a subjective representation of where the maximum areas of divergence/convergence are located.  Depending on the vertical structure of the ridge/trough, the best divergence or convergence could be closer to the axis.