Interplanetary Magnetic Microstructure Observed by Sakigake Near Its Closest Approach to Comet Halley

摘要

Interplanetary magnetic structures at 7 x 10 to the 6th km upstream from Comet Halley were observed by Sakigake on 11 March, 1986. IMF variations associated with multiple crossings of the heliospheric neutral sheet were detected on the same day. Two peculiar regions were found to exist near the neutral sheet, i.e., (1) a region where anomalously many tangential and no discontinuities occurred, and (2) a region where rotational discontinuities occurred predominantly. The field intensity was weak and changed easily in the former region, while it was steady and strong in the latter region.