Three-dimensional structure of the heliosphere as inferred from observations with a Japanese Halley spacecraftA sinusoidal neutral line with a pair of giant regions appeared on the sun about one year before the launch of 'Sakigake', the first of two Japanese Comet Halley spacecraft. The Sakigake magnetometer data during the early part of the mission (February-March 1985) are well interpreted by an eastward shift of the tilting neutral sheet. The shift is further explained by an effect of a new giant region appearing at about 10 deg heliolatitude and about 50 deg Carrington longitude in August 1984. The toward polarity ratio of IMF observed by Sakigake changed from about 22 percent in February to about 62 percent in early June and then increased rapidly up to 98 percent. This ratio is interpreted as a decrease of the tilt angle of the sheet down to only about 4 deg. It is the first spacecraft observation of 'the disappearing sector structure' with such small tilt angle.
Document ID
19870025959
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Saito, T. (Tohoku Univ. Sendai, Japan)
Yumoto, K. (Tohoku University Sendai, Japan)
Hirao, K. (Tohoku Univ. Sendai, Japan)
Aoyama, I. (Tokai University Kanagawa, Japan)
Smith, E. J. (California Institute of Technology Jet Propulsion Laboratory, Pasadena, United States)