p-mode interaction with sunspots

P. S. Cally, H. Moradi, S. P. Rajaguru

Research output: Chapter in Book/Report/Conference proceedingChapter (Book)Researchpeer-review

3 Citations (Scopus)


This chapter brings together two of the prominent features of our star the Sun: its well-developed p-mode spectrum of global oscillations excited by near-surface convection, and its magnetic activity famously represented by sunspots. Modern developments in observations of p-mode and sunspot magnetic field interactions have helped bridge the gap between theory and observations: both the oscillations within a sunspot and in the immediate surroundings of the sunspot appear to be due to magnetohydrodynamics waves driven by p-modes with characteristic spatial patterns of frequencies intimately related to magnetic inclination and the height variation of the plasma p = 1 layer. The chapter makes the case that the behavior of waves in sunspots is dominated by four processes: the ramp effect; fast-to-slow mode conversion; fast-wave reflection; and fast-to-Alfvén mode conversion. The chapter then discusses some of the major developments in helioseismic forward and inverse modeling that have occurred over the last decade.
Original languageEnglish
Title of host publicationLow-Frequency Waves in Space Plasmas
EditorsAndreas Keiling, Dong-Hun Lee, Valery Nakariakov
Place of PublicationHoboken NJ USA
PublisherJohn Wiley & Sons
Number of pages14
ISBN (Electronic)9781119055006
ISBN (Print)9781119054955
Publication statusPublished - 12 Feb 2016

Publication series

NameGeophysical Monograph Series
PublisherAmerican Geophysical Union
ISSN (Print)0065-8448
ISSN (Electronic)2328-8779


  • sunspots
  • MHD waves
  • Helioseismology

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