Investigating the rose of strong magnetic fields on helioseismic wave propagation and the consequences for time-distance helioseismology

Hamed Moradi, Shravan M Hanasoge, Paul Stuart Cally

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

Abstract

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. We confirm 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 mode, and finally, (iii) despite its seeming limitations, MHD ray theory appears to succeed in capturing the essence of the travel-time variations as derived from the MHD simulations.
Original languageEnglish
Title of host publicationSolar-Stellar Dynamos as Revealed by Helio-and Asteroseismology: GONG2008/SOHO 21
EditorsM Dikpati, T Arentoft, I Gonzalez Hernandez, C Lindsey, F Hill
Place of PublicationSan Francisco California USA
PublisherAstronomical Society of the Pacific
Pages143 - 146
Number of pages4
Volume416
ISBN (Print)9781583817124
Publication statusPublished - 2009
EventJoint Conference of the Global Oscillation Network Group and Solar and Heliospheric Observatory (GONG/SOHO) 2009 - High Altitude Observatory Boulder Colorado USA, San Francisco California USA
Duration: 1 Jan 2009 → …

Conference

ConferenceJoint Conference of the Global Oscillation Network Group and Solar and Heliospheric Observatory (GONG/SOHO) 2009
CitySan Francisco California USA
Period1/01/09 → …

Cite this

Moradi, H., Hanasoge, S. M., & Cally, P. S. (2009). Investigating the rose of strong magnetic fields on helioseismic wave propagation and the consequences for time-distance helioseismology. In M. Dikpati, T. Arentoft, I. G. Hernandez, C. Lindsey, & F. Hill (Eds.), Solar-Stellar Dynamos as Revealed by Helio-and Asteroseismology: GONG2008/SOHO 21 (Vol. 416, pp. 143 - 146). San Francisco California USA: Astronomical Society of the Pacific.
Moradi, Hamed ; Hanasoge, Shravan M ; Cally, Paul Stuart. / Investigating the rose of strong magnetic fields on helioseismic wave propagation and the consequences for time-distance helioseismology. Solar-Stellar Dynamos as Revealed by Helio-and Asteroseismology: GONG2008/SOHO 21. editor / M Dikpati ; T Arentoft ; I Gonzalez Hernandez ; C Lindsey ; F Hill. Vol. 416 San Francisco California USA : Astronomical Society of the Pacific, 2009. pp. 143 - 146
@inproceedings{25526c40216c4611a7f4001f82f9c24e,
title = "Investigating the rose of strong magnetic fields on helioseismic wave propagation and the consequences for time-distance helioseismology",
abstract = "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. We confirm 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 mode, and finally, (iii) despite its seeming limitations, MHD ray theory appears to succeed in capturing the essence of the travel-time variations as derived from the MHD simulations.",
author = "Hamed Moradi and Hanasoge, {Shravan M} and Cally, {Paul Stuart}",
year = "2009",
language = "English",
isbn = "9781583817124",
volume = "416",
pages = "143 -- 146",
editor = "M Dikpati and T Arentoft and Hernandez, {I Gonzalez} and C Lindsey and F Hill",
booktitle = "Solar-Stellar Dynamos as Revealed by Helio-and Asteroseismology: GONG2008/SOHO 21",
publisher = "Astronomical Society of the Pacific",
address = "United States of America",

}

Moradi, H, Hanasoge, SM & Cally, PS 2009, Investigating the rose of strong magnetic fields on helioseismic wave propagation and the consequences for time-distance helioseismology. in M Dikpati, T Arentoft, IG Hernandez, C Lindsey & F Hill (eds), Solar-Stellar Dynamos as Revealed by Helio-and Asteroseismology: GONG2008/SOHO 21. vol. 416, Astronomical Society of the Pacific, San Francisco California USA, pp. 143 - 146, Joint Conference of the Global Oscillation Network Group and Solar and Heliospheric Observatory (GONG/SOHO) 2009, San Francisco California USA, 1/01/09.

Investigating the rose of strong magnetic fields on helioseismic wave propagation and the consequences for time-distance helioseismology. / Moradi, Hamed; Hanasoge, Shravan M; Cally, Paul Stuart.

Solar-Stellar Dynamos as Revealed by Helio-and Asteroseismology: GONG2008/SOHO 21. ed. / M Dikpati; T Arentoft; I Gonzalez Hernandez; C Lindsey; F Hill. Vol. 416 San Francisco California USA : Astronomical Society of the Pacific, 2009. p. 143 - 146.

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

TY - GEN

T1 - Investigating the rose of strong magnetic fields on helioseismic wave propagation and the consequences for time-distance helioseismology

AU - Moradi, Hamed

AU - Hanasoge, Shravan M

AU - Cally, Paul Stuart

PY - 2009

Y1 - 2009

N2 - 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. We confirm 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 mode, and finally, (iii) despite its seeming limitations, MHD ray theory appears to succeed in capturing the essence of the travel-time variations as derived from the MHD simulations.

AB - 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. We confirm 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 mode, and finally, (iii) despite its seeming limitations, MHD ray theory appears to succeed in capturing the essence of the travel-time variations as derived from the MHD simulations.

M3 - Conference Paper

SN - 9781583817124

VL - 416

SP - 143

EP - 146

BT - Solar-Stellar Dynamos as Revealed by Helio-and Asteroseismology: GONG2008/SOHO 21

A2 - Dikpati, M

A2 - Arentoft, T

A2 - Hernandez, I Gonzalez

A2 - Lindsey, C

A2 - Hill, F

PB - Astronomical Society of the Pacific

CY - San Francisco California USA

ER -

Moradi H, Hanasoge SM, Cally PS. Investigating the rose of strong magnetic fields on helioseismic wave propagation and the consequences for time-distance helioseismology. In Dikpati M, Arentoft T, Hernandez IG, Lindsey C, Hill F, editors, Solar-Stellar Dynamos as Revealed by Helio-and Asteroseismology: GONG2008/SOHO 21. Vol. 416. San Francisco California USA: Astronomical Society of the Pacific. 2009. p. 143 - 146