NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Observations of field-aligned currents, waves, and electric fields at substorm onsetSubstorm onsets, identified Pi 2 pulsations observed on the Air Force Geophysics Laboratory Magnetometer Network, are studied using magnetometer and electric field data from ISEE 1 as well as magnetometer data from the geosynchronous satellites GOES 2 and 3. The mid-latitude magnetometer data provides the means of both timing and locating the substorm onset so that the spacecraft locations with respect to the substorm current systems are known. During two intervals, each containing several onsets or intensifications, ISEE 1 observed field-aligned current signatures beginning simultaneously with the mid-latitude Pi 2 pulsation. Close to the earth broadband bursts of wave noise were observed in the electric field data whenever field-aligned currents were detected. One onset occurred when ISEE 1 and GOES 2 were on the same field line but in opposite hemispheres. During this onset ISEE 1 and GOES 2 saw magnetic signatures which appear to be due to conjugate field-aligned currents flowing out of the western end of the westward auroral electrojets. The ISEE 1 signature is of a line current moving westward past the spacecraft. During the other interval, ISEE 1 was in the near-tail region near the midnight meridian. Plasma data confirms that the plasma sheet thinned and subsequently expanded at onset. Electric field data shows that the plasma moved in the opposite direction to the plasma sheet boundary as the boundary expanded which implies that there must have been an abundant source of hot plasma present. The plasma motion was towards the center of the plasma sheet and earthwards and consisted of a series of pulses rather than a steady flow.
Document ID
19860037048
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Smits, D. P.
(Boston University MA; Magnetic Observatory, Hermanus, Republic of South Africa, United States)
Hughes, W. J.
(Boston University MA, United States)
Cattell, C. A.
(California, University Berkeley, United States)
Russell, C. T.
(California, University Los Angeles, United States)
Date Acquired
August 12, 2013
Publication Date
January 1, 1986
Publication Information
Publication: Journal of Geophysical Research
Volume: 91
ISSN: 0148-0227
Subject Category
Geophysics
Accession Number
86A21786
Funding Number(s)
CONTRACT_GRANT: NAG5-375
CONTRACT_GRANT: NAG5-237
CONTRACT_GRANT: NAS5-25772
CONTRACT_GRANT: NAS5-25770
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available