CHAPLIN, W. J., ELSWORTH, Y., ISAAK, G. R., MILLER, B. A., NEW, R. and TOUTAIN, T. (2003). Does the energy supplied to low-l solar p-modes vary over the activity cycle? Astrophysical journal, 582 (2), L115-L119.Full text not available from this repository.
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.
|Research Institute, Centre or Group:||Materials and Engineering Research Institute > Thin Films Research Centre > Nanotechnology Centre for PVD Research|
|Depositing User:||Ann Betterton|
|Date Deposited:||08 Jun 2010 10:03|
|Last Modified:||08 Jun 2010 10:03|
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