タイトル | Direct Measurement of Wave Kernels in Time-Distance Helioseismology |
著者(英) | Duvall, T. L., Jr. |
著者所属(英) | NASA Goddard Space Flight Center |
発行日 | 2006-01-01 |
言語 | eng |
内容記述 | Solar f-mode waves are surface-gravity waves which propagate horizontally in a thin layer near the photosphere with a dispersion relation approximately that of deep water waves. At the power maximum near 3 mHz, the wavelength of 5 Mm is large enough for various wave scattering properties to be observable. Gizon and Birch (2002,ApJ,571,966)h ave calculated kernels, in the Born approximation, for the sensitivity of wave travel times to local changes in damping rate and source strength. In this work, using isolated small magnetic features as approximate point-sourc'e scatterers, such a kernel has been measured. The observed kernel contains similar features to a theoretical damping kernel but not for a source kernel. A full understanding of the effect of small magnetic features on the waves will require more detailed modeling. |
NASA分類 | Geophysics |
権利 | No Copyright |
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