Abstract:
Wave propagation in sunspot umbrae is analyzed; the stratification in a typical umbra is approximated by a model atmosphere, extending vertically from a depth of a few thousand kilometers below the photosphere, to the transition region. A Rayleigh-Ritz variational technique is used to calculate the normal mode frequencies of the umbra for different values of the horizontal wave number. The nature of the wave modes is examined by decomposing the eigenvectors into longitudinal and transverse components.
