Heliocentric distance dependence of the interplanetary magnetic field

Technical Report · Fri Jul 01 04:00:00 EDT 1977

OSTI ID:6843364

Behannon, K W

Recent and ongoing planetary missions have provided extensive observations of the variations of the Interplanetary Magnetic Field (IMF) both in time and with heliocentric distance from the sun. Large time variations in both the IMF and its fluctuations were observed. These are produced predominantly by dynamical processes in the interplanetary medium associated with stream interactions. Magnetic field variations near the sun are propagated to greater heliocentric distances, also contributing to the observed variablity of the IMF. Temporal variations on a time-scale comparable to or less than the corotation period complicate attempts to deduce radial gradients of the field and its fluctuations from the various observations. However, recent measurements inward to 0.46 AU and outward to 5 AU suggest that the radial component of the field on average decreases approximately as r to the minus second power, while the azimuthal component decreases more rapidly than the r to the minum first power dependence predicted by simple theory. This, and other observations, are discussed.

• Research Organization: National Aeronautics and Space Administration, Greenbelt, Md. (USA). Goddard Space Flight Center
• OSTI ID: 6843364
• Report Number(s): N-77-34068; NASA-TM-X-71398; X-692-77-196
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
INTERPLANETARY MAGNETIC FIELDS
MAGNETIC FIELDS
SOLAR ACTIVITY
SOLAR WIND
SPACE DEPENDENCE
TIME DEPENDENCE
VARIATIONS