Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
THE MAGNETIC HELICITY INJECTED BY SHEARING MOTIONS P. DMOULIN1, C. H. MANDRINI2,, L VAN DRIEL-GESZTELYI1,3,4,5,
 

Summary: THE MAGNETIC HELICITY INJECTED BY SHEARING MOTIONS
P. DÉMOULIN1, C. H. MANDRINI2,, L VAN DRIEL-GESZTELYI1,3,4,5,
M. C. LOPEZ FUENTES2 and G. AULANIER1
1Observatoire de Paris, section Meudon, DASOP, URA 2080 (CNRS), F-92195 Meudon Principal
Cedex, France, (e-mail: pascal.demoulin@obspm.fr)
2Instituto de Astronomía y Física del Espacio, IAFE, CC. 67 Suc. 28, 1428 Buenos Aires,
Argentina, (e-mail: mandrini@iafe.uba.ar)
3Mullard Space Science Laboratory, University College London, U.K.
4Konkoly Observatory, Hungary
5Centre for Plasma Astrophysics, K.U. Leuven, Celestijnenlaan 200B, 3001 Heverlee, Belgium
(Received 19 September 2001; accepted 4 December 2001)
Abstract. Photospheric shearing motions are one of the possible ways to inject magnetic helicity
into the corona. We explore their efficiency as a function of their particular properties and those of the
magnetic field configuration. Based on the work of M. A. Berger, we separate the helicity injection
into two terms: twist and writhe. For shearing motions concentrated between the centers of two
magnetic polarities the helicity injected by twist and writhe add up, while for spatially more extended
shearing motions, such as differential rotation, twist and writhe helicity have opposite signs and
partially cancel. This implies that the amount of injected helicity can change in sign with time even
if the shear velocity is time independent. We confirm the amount of helicity injected by differential
rotation in a bipole in the two particular cases studied by DeVore (2000), and further explore the

  

Source: Aulanier, Guillaume - Observatoire de Paris

 

Collections: Physics