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Abstract
The solarcyle variation of acoustic mode frequencies has a frequency dependence related to the inverse mode inertia. The discrepancy between model predictions and measured oscillation frequencies for solar and solartype stellar acoustic modes includes a significant frequencydependent term known as the surface term that is also related to the inverse mode inertia. We parametrize both the surface term and the frequency variations for lowdegree solar data from Birmingham SolarOscillations Network (BiSON) and mediumdegree data from the Global Oscillations Network Group (GONG) using the mode inertia together with cubic and inverse frequency terms. We find that for the central frequency of rotationally split multiplets the cubic term dominates both the average surface term and the temporal variation, but for the mediumdegree case the inverse term improves the fit to the temporal variation. We also examine the variation of the evenorder splitting coefficients for the mediumdegree data and find that, as for the central frequency, the latitudedependent frequency variation, which reflects the changing latitudinal distribution of magnetic activity over the solar cycle, can be described by the combination of a cubic and an inverse function of frequency scaled by inverse mode inertia. The results suggest that this simple parametrization could be used to assess the activityrelated frequency variation in solarlike asteroseismic targets.
Original language  English 

Journal  Royal Astronomical Society. Monthly Notices 
Volume  463 
Issue number  2 
Early online date  17 Oct 2016 
DOIs  
Publication status  Epub ahead of print  17 Oct 2016 
Keywords
 Sun
 helioseismology
 oscillations
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Dive into the research topics of 'Parametrizing the timevariation of the ''surface term'' of stellar pmode frequencies: application to helioseismic data'. Together they form a unique fingerprint.Projects
 1 Finished

Asteroseismology and Helioseismology at Birmingham and Queen Mary
Chaplin, B., Elsworth, Y. & Miglio, A.
SCIENCE & TECHNOLOGY FACILITIES COUNCIL
1/04/15 → 30/09/18
Project: Research Councils