A Comparison of Global Intensity and Velocity Helioseismic Data From SOI/MDI and GONG
Abstract
Helioseismology seeks to infer the properties of the solar interior from global oscillation mode parameters (frequency, power, line width). Qualitative differences, such as substantial frequency shifts, have been observed in data obtained simultaneously in Doppler velocity (V) and total intensity (I). Clearly, the physics of the oscillation determining the mode parameters cannot depend on the quantity we observe from the Earth. These differences are thus probably related to the damping and excitation processes of the oscillation modes, which are not completely understood. A comparison of intensity and velocity data is explored both in GONG and MDI data. We first derive the relative phase and coherence between V and I, with the ultimate goals of obtaining the central frequency of the real solar oscillation modes simultaneously from V and I data, and testing models of the damping and excitation processes.
- Publication:
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AGU Spring Meeting Abstracts
- Pub Date:
- May 2001
- Bibcode:
- 2001AGUSM..SP31A12B
- Keywords:
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- 7522 Helioseismology