Parker spiral configuration of the interplanetary magnetic field between 1 and 8. 5 AU

Journal Article · Mon Dec 01 04:00:00 EST 1980 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA085iA12p06861· OSTI ID:6708218

Thomas, B T; Smith, E J

An analysis is presented of the magnetic field data obtained by the Pioneer 10 and 11 spacecraft. The purpose is to provide a quantitative picture of the overall configuration of the interplanetary magnetic field in the outer heliosphere. The field directions observed between 1 and 8.5 AU are found, on average, to conform to the Parker spiral directions within both quiet regions and interaction regions to an overall accuracy of 1.1 /sup 0/. The average latitude angle of the field is shown to be zero within a similar accuracy. The included angle between the inward and ourward sectored field directions is found to be very close to 180 /sup 0/ and displays no solar cycle dependent trends, such as have been previously reported. The field direction is shown to display greater variability in quiet regions than in interaction regions, a fact which is important in terms of the effect of interaction regions on the propagation of energetic particles. The fractional polarities for observations below 10 /sup 0/ heliographic latitude are shown to be dominated by temporal variations; however, dual-spacecraft studies have allowed a significant latitudinal gradient to be extracted. This result is qualitatively consistent with the almost complete disappearance of the inward sector at 16 /sup 0/ heliographic latitude, although it is suggested that the latter effect may be due to a lower than average current sheet inclination in 1976. The sector structure is shown to extend occasionally to these high latitudes during this time, implying a defection of the equatorial current sheet, in association with individual interaction regions. It is suggested that the fast streams associated with interaction regions may move the current sheet to higher heliographic latitudes when the source of the fast plasma is in the southern solar hemisphere.

• Research Organization: Jet Propulstion Laboratory, California Institute of Technology, Pasadena, California 91103
• OSTI ID: 6708218
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 85:A12; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
INTERPLANETARY MAGNETIC FIELDS
INTERPLANETARY SPACE
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
PIONEER SPACE PROBES
RADIATION TRANSPORT
SOLAR ACTIVITY
SOLAR CYCLE
SOLAR WIND
SPACE
SPACE VEHICLES
VARIATIONS
VEHICLES