IAFE   05512
INSTITUTO DE ASTRONOMIA Y FISICA DEL ESPACIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Linking solar to interplanetary events: A new direct method to quantify global MHD magnitudes in magnetic clouds
Autor/es:
DASSO S.; MANDRINI C.H.; DEMOULIN P.
Lugar:
Prague, Czech Republic,
Reunión:
Conferencia; Solar Active Regions and 3D Magnetic Structure, 26th meeting of the IAU, Joint Discussion 3, 16-17 August, 2006, Prague, Czech Republic; 2006
Institución organizadora:
IAU
Resumen:
Magnetic Clouds (MCs) carry a significant amount of magnetic flux (MF)
and helicity (MH) away from the solar corona as they travel to the outer
heliosphere. From a theoretical point of view, MH is a conserved
magnitude in the solar corona and heliosphere; thus, it is expected that
MH be preserved in MCs during their evolution through the interplanetary
medium. In this sense, MH plays a key role to link the magnetic
properties of MCs with their solar active region (AR) sources, helping
us to improve the knowledge of the ejection mechanisms in the corona. We
present here a new method to compute MH in clouds, which provides values
for the helicity per unit length along the flux tube axis using the
observed interplanetary magnetic field, without assuming a given model
to describe the twist of magnetic field lines inside the MC. This method
let us also determine the cloud boundaries with more precision, which
improves the estimation of MH. We apply this method to two MCs, one of
the biggest and one of the smallest ever observed, and compare our
results with the helicity ejected from their respective solar sources.