Gordovskyy, M., Jain, R. and Hindman, B.W. (2009) The role of mode-mixing in the absorption of p-modes. The Astrophysical Journal, 694 (2). pp. 1602-1609.
Observations show that a p-mode may lose up to 70% of its energy flux when it interacts with a sunspot. Part of the absorbed energy is assumed to be converted into other types of waves, while part of it is re-emitted into modes with different radial orders n. In the present paper, we investigate absorption of p-modes with the azimuthal order m = 0 due to their interaction with magnetic flux tubes and attempt to determine the role of mode mixing in this phenomenon. We consider the linearized magnetohydrodynamic equations in two-dimensional, cylindrical geometry, with all the model parameters depending only on radius r and depth z. It is assumed that the wave field may be decomposed into incoming and outgoing components that separately satisfy the governing equations. These components are calculated numerically using a second-order Runge-Kutta finite difference scheme. The calculations reveal substantial scattering from higher-to-lower radial orders n, predominantly into the f-mode (n = 0). Only weak scattering occurs from lower-to-higher radial orders. At the same time, the amount of energy transferred from the p-modes to the f-mode can account for 25%-30% of the energy lost by an incoming p-mode.
|Institution:||The University of Sheffield|
|Academic Units:||The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematics and Statistics (Sheffield)|
|Depositing User:||Mrs Megan Hobbs|
|Date Deposited:||09 Mar 2010 16:05|
|Last Modified:||16 Nov 2015 11:48|
|Publisher:||Institute of Physics|