Sources of magnetic fields in recurrent interplanetary streams

Journal Article · Fri Sep 01 04:00:00 EDT 1978 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA083iA09p04177· OSTI ID:6854773

Burlaga, L F; Behannon, K W; Hansen, S F; Pneuman, G W; Feldman, W C

We examined the sources of magnetic fields in recurrent streams observed by the Imp 8 and Heos spacecraft at 1 AU and by Mariner 10 en route to Mercury between October 31, 1972, and February 9, 1974, during Carrington rotations 1607-1610. Most fields and plasmas at 1 AU were related to coronal holes, and the magnetic field lines were open in those holes. However, some of the magnetic fields and plasmas at 1 AU were related to open field line regions on the sun which were not associated with known coronal holes, indicating that open field lines may be more basic than coronal holes as sources of the solar wind. Magnetic field intensities in five equatorial coronal holes, estimated by projecting the measured interplanetary magnetic fields back to the sun by using the principle of flux conservation ranged from 2 to 18 G with an average of 9 G. Average measured photospheric magnetic fields along the footprints of the corresponding unipolar fields on circular equatorial arcs at 2.5 R/sub s/ had a similar range and average, but in two cases the intensities were approximately 3 times higher than the projected intensities. The coronal footprints of the sector boundaries on the source surface at 2.5 R/sub s/, determined by a potential field extrapolation of the measured photospheric fields, meandered between -45/sup 0/ and +45/sup 0/ latitude, and their inclination with respect to the solar equator ranged from near 0/sup 0/ at some longitudes to near 90/sup 0/ at others. It is possible that sector boundaries are related to convergence surfaces of the flow near the sun. The high densities observed near sector boundaries between streams might be due in part to the convergence of flows from adjacent coronal holes.

• Research Organization: NASA/Goddard Space Flight Center, Laboratory for Extraterrestrial Physics, Greenbelt, Maryland 20771
• OSTI ID: 6854773
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 83:A9; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
IMP SATELLITES
INTERPLANETARY MAGNETIC FIELDS
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
MAGNETIC FLUX
MARINER SPACE PROBES
SATELLITES
SOLAR ACTIVITY
SOLAR CORONA
SOLAR WIND
SPACE VEHICLES