Reference Models of Sunspot Chromospheres
Recent observational and theoretical studies of the structure of umbral chromospheres have led us to propose new models of the region. We combine space and ground based determinations of the density, temperature structure of the transition region with existing CaII H, K, and IR triplet spectral data to establish relatively high density, ‘gradient’ models of the sunspot chromosphere.
Avrett in 1981 presented the Sunspot Sunspot Model which can be characterized as a physically extended, low density, plateau model. However, in a similar study, the authors (Beebe et al., 1982) pointed out that the relatively high transition region pressures derived from space observations indeed are required to reproduce high resolution Can spectral features. Studies of the umbral chromosphere as a resonant cavity for slow-mode magneto-acoustic waves producing umbral oscillations (Zhugzhda et al., 1984) also lead to atmospheres of relatively small physical thickness, thus higher densities.
KeywordsSolar Phys Resonant Cavity Sunspot Umbra Solar Maximum Mission Vacuum Tower
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- Avrett, E. H.: 1981, L. E. Cram and J. H. Thomas (eds.), The Physics of Sunspots, Proceedings, Sac. Peak Obs., p. 235.Google Scholar