Reconstructed global feature of an interplanetary disturbance for the full-halo coronal mass ejection event on 1999 September 20

Traveling interplanetary (IP) disturbances associated with the full-halo coronal mass ejection (CME) which occurred on September 20, 1999, were observed clearly with the 327-MHz interplanetary scintillation (IPS) system of the Solar-Terrestrial Environment Laboratory of Nagoya University. In this study, we retrieved the global features of the IP disturbances by fitting a three-dimensional model to our IPS data. We obtained a best fit model, which had a bubble-like structure with a center axis shifted south with respect to the Sun-Earth line and a nearly isotropic angular span. We believe this feature represents the compression region between the IP shock and the CME. The reconstructed global feature was found to be in good agreement with in situ measurements by ACE and the Nozomi spacecraft, which were situated near the earth and distant from the Earth, respectively, at the time of the full-halo CME event.