Analyzing supergranular power spectra using helioseismic normal-mode coupling
| Autor: | Katepalli R. Sreenivasan, Shravan M. Hanasoge, Chris S. Hanson |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Coupling
Physics 010504 meteorology & atmospheric sciences Wave propagation FOS: Physical sciences Spectral density Astronomy and Astrophysics Solar radius 01 natural sciences Spectral line Computational physics Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Normal mode Dispersion relation 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics Supergranulation 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) 0105 earth and related environmental sciences |
| Popis: | Normal-mode coupling is a technique applied to probe the solar interior using surface observations of oscillations. The technique, which is straightforward to implement, makes more use of the seismic information in the wavefield than other comparable local imaging techniques and therefore has the potential to significantly improve current capabilities. Here, we examine supergranulation power spectra using mode-coupling analyses of intermediate-to-high-degree modes by invoking a Cartesian-geometric description of wave propagation under the assumption that the localized patches are much smaller in size than the solar radius. We extract the supergranular power spectrum and compare the results with prior helioseismic studies. Measurements of the dispersion relation and life times of supergranulation, obtained using near surface modes (f and p$_1$), are in accord with the literature. We show that the cross-coupling between the p$_2$ and p$_3$ acoustic modes, which are capable of probing greater depths, are also sensitive to supergranulation. 7 pages, 3 figures, Accepted into ApJ |
| Databáze: | OpenAIRE |
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