Determining the characteristics of halo coronal mass ejections

Abstract

Halo CMEs represent the three-dimensional moving structures, located out of the plane of the sky (Howard et al. 1982, St. Cyr et al. 2000). At that one halo CMEs move toward the Earth (frontside Halo CMEs), other - away from the Earth, St. Cyr. Frontside halo CMEs play the special role in phenomena, associated with space weather, Crosby (2001). The largest geomagnetic storms are caused by influencing such CMEs on the magnetosphere of the Earth (Webb et al. 2000, St. Cyr et al. 2000). Using the images of halo CMEs in the field of view of a coronagraph it is possible to determine only their apparent characteristics in the plane of the sky. But in this case it is difficult define its important parameters such as directions of movement, angular sizes in various sections of CME, position of the CME “center” or of its front, velocities of CME elements along directions which are not located in the plane of the sky. Without these parameters it is impossible to find the mass of CME, it's kinetic and potential energy. In the present work the methods are offered and approved allowing the estimation of the listed above halo CMEs parameters, which are determined with difficulty.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html