Skip to main content

Active Region Formation through the Negative Effective Magnetic Pressure Instability

  • Chapter
Solar Dynamics and Magnetism from the Interior to the Atmosphere

Abstract

The negative effective magnetic-pressure instability operates on scales encompassing many turbulent eddies, which correspond to convection cells in the Sun. This instability is discussed here in connection with the formation of active regions near the surface layers of the Sun. This instability is related to the negative contribution of turbulence to the mean magnetic pressure that causes the formation of large-scale magnetic structures. For an isothermal layer, direct numerical simulations and mean-field simulations of this phenomenon are shown to agree in many details, for example the onset of the instability occurs at the same depth. This depth increases with increasing field strength, such that the growth rate of this instability is independent of the field strength, provided the magnetic structures are fully contained within the domain. A linear stability analysis is shown to support this finding. The instability also leads to a redistribution of turbulent intensity and gas pressure that could provide direct observational signatures.

Solar Dynamics and Magnetism from the Interior to the Atmosphere

Guest Editors: R. Komm, A. Kosovichev, D. Longcope, and N. Mansour

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 129.00
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 169.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 169.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Koen Kemel .

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2012 Springer Science+Business Media B.V.

About this chapter

Cite this chapter

Kemel, K., Brandenburg, A., Kleeorin, N., Mitra, D., Rogachevskii, I. (2012). Active Region Formation through the Negative Effective Magnetic Pressure Instability. In: Mansour, N.N., Kosovichev, A.G., Komm, R., Longcope, D. (eds) Solar Dynamics and Magnetism from the Interior to the Atmosphere. Springer, New York, NY. https://doi.org/10.1007/978-1-4899-8005-2_19

Download citation

Publish with us

Policies and ethics