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Numerical models of travel-time inhomogeneities in sunspots View all abstracts by submitter

Hamed Moradi   Submitted: 2008-11-09 00:01

We investigate the direct contribution of strong, sunspot-like magnetic fields to helioseismic wave travel-time shifts via two numerical forward models, a 3D ideal MHD solver and MHD ray theory. The simulated data cubes are analyzed using the traditional time-distance center-to-annulus measurement technique. We also isolate and analyze the direct contribution from purely thermal perturbations to the observed travel-time shifts, confirming some existing ideas and bring forth new ones: (i) that the observed travel-time shifts in the vicinity of sunspots are largely governed by MHD physics, (ii) the travel-time shifts are sensitively dependent on frequency and phase-speed filter parameters and the background power below the p1 ridge, and finally, (iii) despite its seeming limitations, ray theory succeeds in capturing the essence of the travel-time variations as derived from the MHD simulations.

Authors: H. Moradi, S. M. Hanasoge, P. S. Cally
Projects: None

Publication Status: Accepted, ApJ Letters.
Last Modified: 2008-11-09 18:21
Go to main E-Print page  Particle trajectories and acceleration during 3D fan reconnection  Phase Jumps in Local Helioseismology  Edit Entry  Download Preprint  Submitter's Homepage Delete Entry 

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