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Solar Oscillation Frequency Changes on Time Scales of Nine Days

S. C. Tripathy·F. Hill·K. Jain·J. W. Leibacher
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Abstract

We establish that global solar p-mode frequencies can be measured with sufficient precision on time scales as short as nine days to detect activity-related shifts. Using ten years of GONG data, we report that mode-mass and error-weighted frequency shifts derived from nine days are significantly correlated with the strength of solar activity and are consistent with long duration measurements from GONG and the MDI/SOHO instrument. However, the correlation varies from year to year and appears to be a complex phenomena. For the short-duration observations, the analysis indicates a higher sensitivity to activity. We also find that magnetic indices behave differently in the rising and falling phases of the activity cycle.

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S. C. Tripathy, F. Hill, K. Jain, J. W. Leibacher. 2007-07-10. Solar Oscillation Frequency Changes on Time Scales of Nine Days. https://doi.org/10.1007/s11207-007-9000-z

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