(a) Eight types of FR. For each type, the heilcal and axial field lines are shown in red and black, respectively. Each letter of the name of the type of FR corresponds to one of four directions, i.e. north, south, east, west, (e.g., NES means north-east-south), and RH and LH denote right-handed and left-handed chirality, respectively. The first and last letters indicate the helical field directions, and the letter in between indicates the axial field direction of the FR. The image is adapted from Palmerio et al. (2018) (b) South-east directed axis of a CME (PQ) similar to the FR of event 4 shown as the cyan line projected on the solar disk. The solar source of the CME (O_s) is indicated by a cyan dot, and the projected location of the Earth (E) on the solar disk is denoted by a green dot. The axis has a negative value of η_cme with respect to the east-west line. The η_cme and η_arcade associated with this FR is −149 and −127, respectively.