Activity Related Variations of High-Degree p-Mode Amplitude, Width and Energy in Solar Active Regions

Abstract

We study the properties of high degree p-mode oscillations in flaring and dormant ARs and compare them with those in corresponding quiet regions (QRs) to find the association of mode parameters with magnetic and flare related activities. Our analysis of several flaring and dormant ARs, showed strong association of mode amplitude, width and energy with magnetic and flare activities although their changes are combined effects of foreshortening, filling factor, magnetic activity, flare activity, and measurement uncertainties. We find that the largest decrease in mode amplitude and background power of an AR are caused by the angular distance of the AR from the solar disc centre. After correcting the mode parameters for foreshortening and filling factor, we find that the mode amplitude of flaring and dormant ARs are smaller than in corresponding QRs, and decreases with increasing MAI suggesting a larger mode power suppression in ARs with stronger magnetic fields. The mode widths in ARs are larger than in corresponding QRs and increase with MAI, indicating shorter lifetimes of modes in ARs than in QRs. The largest decrease (increase) in mode amplitude (mode width) of dormant ARs is found in the five minute frequency band. The average mode energy of both the flaring and dormant ARs are smaller than in their corresponding QRs, decreasing with increasing MAI. But the average mode energy decrease rate in flaring ARs are smaller than in dormant ARs. Also, the increase in mode width rate in dormant (flaring) ARs is followed by decrease (increase) in amplitude variation rate. Furthermore, inclusion of mode corrections for MAI shows that mode amplitude and mode energy of flaring ARs increase with FI while mode width shows an opposite trend. The increase (decrease) in mode amplitude (width) is larger in the five minute and higher frequency band. Increase in width variation rate is ...

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Cited by in corpus (2)

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