Test of magnetic field draping induced B/sub z/ perturbations ahead of fast coronal mass ejecta

Recent studies have suggested that the ambient interplanetary magnetic field (IMF) drapes about fast coronal mass ejections (CMEs) as they plow out through slower moving, quiescent solar wind. In this study we examine ISEE 3 plasma and magnetic field data in order to look for observational evidence of IMF draping ahead of fast CMEs. Since the upstream IMF is excluded from CMEs, the ambient field must drape about these ejecta and connect back to the Sun around their edges. For example, for a purely radial, inward directed IMF, this would mean taht a CME which extends into the ecliptic plane while being directed northward of its hould give rise to a southward B/sub z/ perturbation in the ecliptic plane ahead of the CME. While purely radial IMF configurations are rare, the radial component of the IMF should also give rise to such B/sub z/ perturbations