Subsurface Circulations Established by Active Regions
Abstract
Using the local helioseismic technique of ring analysis we deduce subsurface flows within and surrounding magnetic active regions. We apply this technique to data from MDI and analyze the resulting flow fields for durations of several months from each of three consecutive years. We compute the mean motion of magnetic plage, mean inflow rates into magnetic complexes and mean circulation speeds around active regions. We find that the plage within active regions rotates more rapidly than quiet sun by roughly 20 m/s, yet advects poleward at the same rate as quiet sun. We also find that almost all active regions possess a mean inflow (20-30 m/s) and a cyclonic circulation ( 5 m/s) at their peripheries; whereas their cores, where the sunspots are located, are zones of strong anticyclonic outflow ( 50 m/s).
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2009
- Pub Date:
- August 2009
- Bibcode:
- 2009shin.confE..17H