INVESTIGADORES
MANDRINI Cristina Hemilse
congresos y reuniones científicas
Título:
A direct method to estimate magnetic helicity in magnetic clouds
Autor/es:
DASSO, S.; MANDRINI, C.H.; GULISANO, A.M.; DÉMOULIN, P.
Lugar:
Beijing, China
Reunión:
Simposio; IAU Symposium 226; 2004
Institución organizadora:
International Astrronomical Union
Resumen:
Abstract. Magnetic clouds are extended and magnetized plasma structures that travel from the
Sun toward the outer heliosphere, carrying an important amount of magnetic helicity. The magnetic
helicity quantifies several aspects of a given magnetic structure, such as the twist, kink, and
the number of knots between magnetic field lines, the linking between magnetic flux tubes, etc.
Since the helicity is practically conserved in the solar atmosphere and the heliosphere, it is a usefui
quantity to compare the physical properties of magnetic clouds to those of their solar source
regions. In this work we describe a method that, assuming a cylindrical geometry for the magnetic
cloud structures, allows us to calculate their helicity (per unit length) content directly from
the observed magnetic field values. We apply the method to a set of 20 magnetic clouds observed
by the WIND spacecraft. To test its reliability we compare our results with the helicity computed
using a linear force-free field model under cylindrical geometry (Le. Lundquist's solution).