Time-distance helioseismology and the magnetic atmoŝphere of the sun

Authors Organisations
Type Conference Proceeding (Non-Journal item)
Original languageEnglish
Title of host publicationProceedings of the Conference SOHO 13 - Waves, Oscillations and Small-Scale Transient Events in the Solar Atmosphere:
Subtitle of host publicationA Joint View from SOHO and TRACE
Pages33-38
Number of pages6
Edition547
Publication statusPublished - 2004
EventProceedings of the Conference SOHO 13 - Waves, Oscillations and Small-Scale Transient Events in the Solar Atmosphere: A Joint View from SOHO and TRACE - Balearic Islands, Spain
Duration: 29 Sep 200303 Oct 2003

Publication series

NameEuropean Space Agency, (Special Publication) ESA SP
ISSN (Print)0379-6566

Conference

ConferenceProceedings of the Conference SOHO 13 - Waves, Oscillations and Small-Scale Transient Events in the Solar Atmosphere: A Joint View from SOHO and TRACE
CountrySpain
CityBalearic Islands
Period29 Sep 200303 Oct 2003
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Abstract

In time-distance helioseismology the travel time of the acoustic waves between different points on the solar surface is measured to infer the local structure and properties of the subsurface layers of the Sun. The presence of the magnetic canopy in the solar atmosphere is expected to modify the behavior of the acoustic waves. The travel time changes due to the atmospheric magnetic field are evaluated theoretically. The uniform magnetic field in the atmosphere shortens the travel time of the acoustic waves due to enhanced rigidity of the interface where the waves are reflected. This effect increases rapidly with increasing frequency and harmonic degree. The effect of the magnetic field on the acoustic wave travel time is compared with the corresponding effect of large-scale sub-surface flows. It is suggested to use the time-distance analysis as a diagnostic tool in determining the local properties of the Sun's atmospheric magnetic field.

Keywords

  • Magnetic canopy, Sun, Time-distance helioseismology