An ice‐cream cone model for coronal mass ejections

In this study, we use an ice‐cream cone model to analyze the geometrical and kinematical properties of the coronal mass ejections (CMEs). Assuming that in the early phase CMEs propagate with near‐constant speed and angular width, some useful properties of CMEs, namely the radial speed ( v ), the angular width (α), and the location at the heliosphere, can be obtained considering the geometrical shapes of a CME as an ice‐cream cone. This model is improved by (1) using an ice‐cream cone to show the near real configuration of a CME, (2) determining the radial speed via fitting the projected speeds calculated from the height‐time relation in different azimuthal angles, (3) not only applying to halo CMEs but also applying to nonhalo CMEs.