Numerical modeling of solar convection and oscillations in magnetic regions

I. N. Kitiashvili, L. Jacoutot, Alexander Kosovichev, A. A. Wray, N. N. Mansour

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)

Abstract

Solar observations show that the spectra of turbulent convection and oscillations significantly change in magnetic regions, resulting in interesting phenomena, such as high-frequency "acoustic halos" around active regions. In addition, recent observations from SOHO/MDI revealed significant changes of the wave properties in inclined magnetic field regions of sunspots, which affect helioseismic inferences. We use realistic 3D radiative MHD numerical simulations to investigate properties of solar convection and excitation and propagation of oscillations in magnetic regions. A new feature of these simulations is implementation of a dynamic sub-grid turbulence model, which allows more accurate description of turbulent dissipation and wave excitation. We present the simulation results for a wide range of the field strength and inclination in the top 6 Mm layer of the convection zone. The results show interesting and unexpected effects in the dynamics and large-scale organization of the magnetoconvection (including traveling waves and shearing flows) and also changes in the excitation properties and spectrum of oscillations, suggesting an explanation of the acoustic "halos" observed above the acoustic cut-off frequency.

Original languageEnglish (US)
Title of host publicationStellar Pulsation
Subtitle of host publicationChallenges for Theory and Observation - Proceedings of the International Conference
Pages569-573
Number of pages5
Volume1170
DOIs
StatePublished - Dec 1 2009
Externally publishedYes
EventInternational Conference on Stellar Pulsation: Challenges for Theory and Observation - Santa Fe, NM, United States
Duration: May 31 2009Jun 5 2009

Other

OtherInternational Conference on Stellar Pulsation: Challenges for Theory and Observation
CountryUnited States
CitySanta Fe, NM
Period5/31/096/5/09

Fingerprint

solar oscillations
oscillations
acoustics
halos
convection
excitation
simulation
wave excitation
turbulence models
sunspots
shearing
inference
traveling waves
inclination
field strength
cut-off
dissipation
grids
propagation
magnetic fields

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Kitiashvili, I. N., Jacoutot, L., Kosovichev, A., Wray, A. A., & Mansour, N. N. (2009). Numerical modeling of solar convection and oscillations in magnetic regions. In Stellar Pulsation: Challenges for Theory and Observation - Proceedings of the International Conference (Vol. 1170, pp. 569-573) https://doi.org/10.1063/1.3246564
Kitiashvili, I. N. ; Jacoutot, L. ; Kosovichev, Alexander ; Wray, A. A. ; Mansour, N. N. / Numerical modeling of solar convection and oscillations in magnetic regions. Stellar Pulsation: Challenges for Theory and Observation - Proceedings of the International Conference. Vol. 1170 2009. pp. 569-573
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title = "Numerical modeling of solar convection and oscillations in magnetic regions",
abstract = "Solar observations show that the spectra of turbulent convection and oscillations significantly change in magnetic regions, resulting in interesting phenomena, such as high-frequency {"}acoustic halos{"} around active regions. In addition, recent observations from SOHO/MDI revealed significant changes of the wave properties in inclined magnetic field regions of sunspots, which affect helioseismic inferences. We use realistic 3D radiative MHD numerical simulations to investigate properties of solar convection and excitation and propagation of oscillations in magnetic regions. A new feature of these simulations is implementation of a dynamic sub-grid turbulence model, which allows more accurate description of turbulent dissipation and wave excitation. We present the simulation results for a wide range of the field strength and inclination in the top 6 Mm layer of the convection zone. The results show interesting and unexpected effects in the dynamics and large-scale organization of the magnetoconvection (including traveling waves and shearing flows) and also changes in the excitation properties and spectrum of oscillations, suggesting an explanation of the acoustic {"}halos{"} observed above the acoustic cut-off frequency.",
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Kitiashvili, IN, Jacoutot, L, Kosovichev, A, Wray, AA & Mansour, NN 2009, Numerical modeling of solar convection and oscillations in magnetic regions. in Stellar Pulsation: Challenges for Theory and Observation - Proceedings of the International Conference. vol. 1170, pp. 569-573, International Conference on Stellar Pulsation: Challenges for Theory and Observation, Santa Fe, NM, United States, 5/31/09. https://doi.org/10.1063/1.3246564

Numerical modeling of solar convection and oscillations in magnetic regions. / Kitiashvili, I. N.; Jacoutot, L.; Kosovichev, Alexander; Wray, A. A.; Mansour, N. N.

Stellar Pulsation: Challenges for Theory and Observation - Proceedings of the International Conference. Vol. 1170 2009. p. 569-573.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

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T1 - Numerical modeling of solar convection and oscillations in magnetic regions

AU - Kitiashvili, I. N.

AU - Jacoutot, L.

AU - Kosovichev, Alexander

AU - Wray, A. A.

AU - Mansour, N. N.

PY - 2009/12/1

Y1 - 2009/12/1

N2 - Solar observations show that the spectra of turbulent convection and oscillations significantly change in magnetic regions, resulting in interesting phenomena, such as high-frequency "acoustic halos" around active regions. In addition, recent observations from SOHO/MDI revealed significant changes of the wave properties in inclined magnetic field regions of sunspots, which affect helioseismic inferences. We use realistic 3D radiative MHD numerical simulations to investigate properties of solar convection and excitation and propagation of oscillations in magnetic regions. A new feature of these simulations is implementation of a dynamic sub-grid turbulence model, which allows more accurate description of turbulent dissipation and wave excitation. We present the simulation results for a wide range of the field strength and inclination in the top 6 Mm layer of the convection zone. The results show interesting and unexpected effects in the dynamics and large-scale organization of the magnetoconvection (including traveling waves and shearing flows) and also changes in the excitation properties and spectrum of oscillations, suggesting an explanation of the acoustic "halos" observed above the acoustic cut-off frequency.

AB - Solar observations show that the spectra of turbulent convection and oscillations significantly change in magnetic regions, resulting in interesting phenomena, such as high-frequency "acoustic halos" around active regions. In addition, recent observations from SOHO/MDI revealed significant changes of the wave properties in inclined magnetic field regions of sunspots, which affect helioseismic inferences. We use realistic 3D radiative MHD numerical simulations to investigate properties of solar convection and excitation and propagation of oscillations in magnetic regions. A new feature of these simulations is implementation of a dynamic sub-grid turbulence model, which allows more accurate description of turbulent dissipation and wave excitation. We present the simulation results for a wide range of the field strength and inclination in the top 6 Mm layer of the convection zone. The results show interesting and unexpected effects in the dynamics and large-scale organization of the magnetoconvection (including traveling waves and shearing flows) and also changes in the excitation properties and spectrum of oscillations, suggesting an explanation of the acoustic "halos" observed above the acoustic cut-off frequency.

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Kitiashvili IN, Jacoutot L, Kosovichev A, Wray AA, Mansour NN. Numerical modeling of solar convection and oscillations in magnetic regions. In Stellar Pulsation: Challenges for Theory and Observation - Proceedings of the International Conference. Vol. 1170. 2009. p. 569-573 https://doi.org/10.1063/1.3246564