  During Solar Cycle 23, some active regions(ARs) produced extremely energetic
flares and CMEs. These ARs are expected to be characteristically distinct as
compared to dormant ARs and quiet regions (QRs). It would be interesting to
identify whether the internal structure and dynamics of the ARs is related to
their flaring/CME activity levels. For this investigation, we have obtained
sub-surface velocity flows in several ARs and QRs using the ring diagram
technique, and then derived the corresponding vorticity vector and kinetic
helicity density.
