Evidence for solar frequency dependence on sunspot type

摘要

High degree solar mode frequencies as measured by ring diagrams are known tochange in the presence of the strong magnetic fields found in active regions.We examine these changes in frequency for a large sample of active regionsanalyzed with data from the Michelson Doppler Imager (MDI) onboard the SoHOspacecraft, spanning most of solar cycle 23. We confirm that the frequenciesincrease with increasing magnetic field strength, and that this dependence isgenerally linear. We find that the dependence is slightly but significantlydifferent for active regions with different sunspot types.