The influence of a semi-infinite atmosphere on solar oscillations

4th International Workshop & Summer School on Plasma Physics 2010

González, Ángel De Andrea^1

Departamento de Física, Escuela Politécnica Superior, Universidad Carlos III de Madrid, Av. Universidad 30, 28911 Leganés, Spain^1

关键词: Cartesian coordinate;    Continuous spectrum;    Discrete spectrum;    Gravitational accelerations;    Initial perturbation;    Mathematical procedures;    Solar oscillations;    Stratified fluid;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/516/1/012015/pdf
DOI  :  10.1088/1742-6596/516/1/012015

来源: IOP

【 摘 要 】

The influence of a semi-infinitive atmosphere on solar investigations is investigated using a model in which the corona is represented by a gravitationally stratified fluid. The solar corona can be modeled as a semi-infinitive region of plasma that occupies the space above the xy- plane in Cartesian coordinates with the z-axis taken along the gravitational acceleration gz. This assumption is reasonable, as the plasma density of the atmosphere is much lower than the density of the photosphere. So, we consider the phostosphere as a solid and immobile boundary for the atmosphere. The standard mathematical procedures in Helioseismology field are based on normal mode approach for various solar models. The region is assumed quasi-isothermal and without magnetic fields. In this work, in order to show how the modes appear in the response to an initial perturbation, we consider the initial value problem (IPV). The p-modes and g-modes possess only continuous spectra -as opposed to discrete spectrum like that previous investigators found for this problem- and the solution to the initial value problem is obtained through an appropiate Green's function.