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Can I read Modelling and Observations of Photospheric Magnetic Helicity on EtoBox?
Modelling and Observations of Photospheric Magnetic Helicity by P. Démoulin; E. Pariat is a Physics and Astronomy article available to read on EtoBox.
What is Modelling and Observations of Photospheric Magnetic Helicity about?
Mounting observational evidence of the emergence of twisted magnetic flux tubes through the photosphere have now been published. Such flux tubes, formed by the solar dynamo and transported through the convection zone, eventually reach the solar atmosphere. Their accumulation in the solar corona leads to flares and coronal mass ejections. Since reconnections occur during the evolution of the flux tubes, the concepts of twist and magnetic stress become inappropriate. Magnetic helicity, as a well preserved quantity, in particular in plasma with high magnetic Reynolds number, is a more suitable physical quantity to use, even if reconnection is involved. Only recently, it has been realized that the flux of magnetic helicity can be derived from magnetogram time series. This paper reviews the advances made in measuring the helicity injection rate at the photospheric level, mostly in active regions. It relates the observations to our present theoretical understanding of the emergence process. Most of the helicity injection is found during magnetic flux emergence, whereas the effect of differential rotation is small, and the long-term evolution of active regions is still puzzling. The photo
Who reads Modelling and Observations of Photospheric Magnetic Helicity?
It is typically read by researchers, students, and practitioners in Physics and Astronomy.
- Author
- P. Démoulin; E. Pariat
- Publisher
- Elsevier Science; Elsevier ; Elsevier Ltd.; Elsevier BV (ISSN 0273-1177)
- Published
- 2009
- Language
- EN
- Field
- Physics and Astronomy (Physical Sciences)