1997/03/17 by J. Theurer, Theurer, J., P. Ulmschneider +3
Earth and Planetary Sciences · Physics and Astronomy · #Astrophysics (astro-ph) #Earthquake Detection and Analysis #FOS: Physical sciences #Solar and Space Plasma Dynamics #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9703106
12 pages, 11 figures, accepted for publication in A & A
arxiv created 1997/03/17 · openalex publication_date 1997/03/17 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We study the response of the solar atmosphere to excitations by large amplitude acoustic waves with radiation damping now included. Monochromatic adiabatic waves, due to unbalanced heating, generate continuously rising chromospheric temperature plateaus in which the low frequency resonances quickly die out. All non-adiabatic calculations lead to stable mean chromospheric temperature distributions determined by shock dissipation and radiative cooling. For non-adiabatic monochromatic wave excitation, a critical frequency fcr ~ 1/25 Hz is confirmed, which separates domains of different resonance behaviour. For waves of frequency f < fcr, the resonances decay, while for waves of f > fcr persistent resonance oscillations occur, which are perpetuated by shock merging. Excitation with acoustic frequency spectra produces distinct dynamical mean chromosphere models where the detailed temperature distributions depend on the shape of the assumed spectra. The stochasticity of the spectra and the ongoing shock merging lead to a persistent resonance behaviour of the atmosphere. The acoustic spectra show a distinct shape evolution with height such that at great height a pure 3 min band becomes increasingly dominant. With our Eulerian code we did not find appreciable mass flows at the top boundary.