Abstract
We report on the average behavior of the excitation and damping of low angular degree (low l) solar p-mode oscillations over the decade from 1991 to 2000 using both long and short time duration Fourier transforms. The data in question were collected by the ground-based Birmingham Solar Oscillations Network. Throughout most of the period under study, the energy supply rate to the modes remains roughly constant-implying a near-constant level of forcing-while the damping and velocity power show a fairly smooth increase and decrease, respectively, in response to increasing levels of solar activity (in line with previous findings). However, here we uncover evidence of there being a sharp increase in the mode velocity power over a brief period of approximately 100 days centered on 1998 late March. The magnitude and sign of this are contrary to the expectation based on the long-timescale, solar-cycle trend; such unusual behavior is absent in the damping. This implies that the forcing of, or rate of energy supplied to, the modes increased in magnitude over this period.
Original language | English |
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Pages (from-to) | L115-L119 |
Journal | The Astrophysical Journal |
Volume | 582 |
Issue number | 2 |
DOIs | |
Publication status | Published - 10 Jan 2003 |
Keywords
- Sun : activity
- waves
- Sun : oscillations