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.