Magnetohydrodynamic properties of solar origin magnetic clouds: a statistical study

GULISANO, A.M.; DASSO, S.; MANDRINI, C.H.; DÉMOULIN, P.

San Juan, Argentina

Congreso; 47 Reunión Anual de la Asociación Argentina de Astronomía; 2004

Asociación Argentina de Astronomía

Magnetic Clouds (MCs) are the interplanetary manifestation of transient expulsions of solar mass, the so-called coronal mass ejections. Despite several statistical works that have been done studying diverse properties of MCs, systematic studies of their magnetohydrodynamic (MHD) global magnitudes, such as their magnetic helicity (MH) and energy, have not yet been undertaken. In this work we present a study of 20 MCs observed by the spacecraft Wind and quantify their MHD properties. The study is performed exploring 4 helical models with substantial differences in the magnetic field twist distribution. We find that the values of the MH content are almost independent from the analyzed models, in the sense that their dispersion when considering different models for a given event is smaller than the dispersion when considering different events.