On the Spatial Dependence of Low-Degree Solar p -Mode Frequency Shifts from Full-Disk and Resolved-Sun Observations

2004 ◽  
Vol 610 (1) ◽  
pp. L65-L68 ◽  
Author(s):  
S. J. Jiménez-Reyes ◽  
R. A. García ◽  
W. J. Chaplin ◽  
S. G. Korzennik
Keyword(s):  
Spatial Dependence ◽  
Mode Frequency ◽  
Frequency Shifts ◽  
Low Degree ◽  
Full Disk

scholarly journals Sensitivity of low-degree solar p modes to active and ephemeral regions: frequency shifts back to the Maunder minimum

2019 ◽  
Vol 489 (1) ◽  
pp. L86-L90 ◽  
Author(s):  
William J Chaplin ◽  
Rachel Howe ◽  
Sarbani Basu ◽  
Yvonne Elsworth ◽  
Timothy W Milbourne ◽  
...  
Keyword(s):  
Active Region ◽  
Magnetic Fields ◽  
Spatial Scales ◽  
Active Regions ◽  
Activity Cycle ◽  
Maunder Minimum ◽  
Field Frequency ◽  
Frequency Shifts ◽  
Near Surface ◽  
Low Degree

ABSTRACT We explore the sensitivity of the frequencies of low-degree solar p modes to near-surface magnetic flux on different spatial scales and strengths, specifically to active regions with strong magnetic fields and ephemeral regions with weak magnetic fields. We also use model reconstructions from the literature to calculate average frequency offsets back to the end of the Maunder minimum. We find that the p-mode frequencies are at least 3 times less sensitive (at 95  per cent confidence) to the ephemeral-region field than they are to the active-region field. Frequency shifts between activity cycle minima and maxima are controlled predominantly by the change of active region flux. Frequency shifts at cycle minima (with respect to a magnetically quiet Sun) are determined largely by the ephemeral flux, and are estimated to have been $0.1\, \rm \mu Hz$ or less over the last few minima. We conclude that at epochs of cycle minimum, frequency shifts due to near-surface magnetic activity are negligible compared to the offsets between observed and model frequencies that arise from inaccurate modelling of the near-surface layers (the so-called surface term). The implication is that this will be the case for other Sun-like stars with similar activity, which has implications for asteroseismic modelling of stars.

scholarly journals About the p-mode frequency shifts in HD 49933

2011 ◽  
Vol 530 ◽  
pp. A127 ◽  
Author(s):  
D. Salabert ◽  
C. Régulo ◽  
J. Ballot ◽  
R. A. García ◽  
S. Mathur
Keyword(s):  
Mode Frequency ◽  
Frequency Shifts

Collective mode frequency shifts in l-serine and a series of isotopologues in the terahertz regime

Talanta ◽  
2012 ◽  
Vol 88 ◽  
pp. 61-65 ◽  
Author(s):  
David C. Hufnagle ◽  
Anita R. Taulbee-Combs ◽  
Wolfgang U. Spendel ◽  
Gilbert E. Pacey
Keyword(s):  
Collective Mode ◽  
Mode Frequency ◽  
Frequency Shifts

Confirmation of solar cycle-dependent intermediate-degree p-mode frequency shifts

1993 ◽  
Vol 406 ◽  
pp. 714 ◽  
Author(s):  
Edward J., Jr. Rhodes ◽  
Alessandro Cacciani ◽  
Sylvain G. Korzennik ◽  
Roger K. Ulrich
Keyword(s):  
Solar Cycle ◽  
Mode Frequency ◽  
Frequency Shifts ◽  
Intermediate Degree ◽  
Cycle Dependent

scholarly journals Changes in the sensitivity of solar p-mode frequency shifts to activity over three solar cycles

2018 ◽  
Vol 480 (1) ◽  
pp. L79-L84 ◽  
Author(s):  
R Howe ◽  
W J Chaplin ◽  
G R Davies ◽  
Y Elsworth ◽  
S Basu ◽  
...  
Keyword(s):  
Mode Frequency ◽  
Solar Cycles ◽  
Frequency Shifts
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