Satellite studies of magnetospheric substorms on August 15, 1968: 2. Solar wind and outer magnetosphere

Journal Article · Fri Jun 01 04:00:00 EDT 1973 · Journal of Geophysical Research

DOI:https://doi.org/10.1029/JA078i016p03054· OSTI ID:4400746

McPherron, R. L.; Parks, G. K.; Colburn, D. S.; Montgomery, M. D.

We continue the study of the sequence of events occurring in the magnetosphere during several substorms on August 15, 1968. We show that the onsets of expansion phases identified in the prcceding paper at aouthward solar wind magnetic field. During the entire interval containing these substorms there was no significant change in the solar wind velocity. Intermittent observations of the solar wind particle density and temperature suggest there were no large changes in the dynamic and static pressure. The fact that the solar wind field remained southward after the onsets of two substorm expansions is interpreted as evidence that the expansion is a process internal to the magnetosphere. However, coincidence of an expansion onset with a large fluctuation of the solar wind field makes it impossible to rule out the possibility that the expansion can be triggered externally. Magnetic field observations in the premidnight sector of the synchronous equatorial orbit show that the earth's field here begins to decrease in response to the beginning of the southward solar wind field. Throughout the interval prior to the onset of the expansion (growth phase) the field continues to decrease. During one of the substorms, energetic electron precipitation was observed during this growth phase. In the expansion phase the field at synchronous orbit recovers.

• Research Organization: Department of Planetary and Space Science and Institute of Geophysics and Planetary Physics, University of California, Los Angeles, California, 90024
• Sponsoring Organization: USDOE
• NSA Number: NSA-29-006031
• OSTI ID: 4400746
• Journal Information: Journal of Geophysical Research, Journal Name: Journal of Geophysical Research Journal Issue: 16 Vol. 78; ISSN 0148-0227
• Publisher: American Geophysical Union
• Country of Publication: United States
• Language: English

Related Subjects

*MAGNETIC BAYS-- EXPANSION
*MAGNETOSPHERE-- MAGNETIC STORMS
*SOLAR WIND-- GEOMAGNETIC FIELD
ELECTRON PRECIPITATION
N58300* --Physics (Atmospheric)--Magnetospheric Phenomena
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