CDAW 9 analysis of magnetospheric events on May 3, 1986: Event C

Journal Article · Mon Mar 01 00:00:00 EST 1993 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/92JA02475· OSTI ID:6873430

Baker, D N ^[1]; Pulkkinen, T I ^[2]; McPherron, R L ^[3]; Craven, J D ^[4]; Frank, L A ^[5]; Elphinstone, R D; Murphree, J S ^[6]; Fennell, J F ^[7]; Lopez, R E ^[8]; Nagai, T ^[9]

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1. NASA Goddard Space Flight Center, Greenbelt, MD (United States)
2. NASA Goddard Space Flight Center, Greenbelt, MD (United States) Finnshish Meteorological Inst., Helsinki (Finland)
3. NASA Goddard Space Flight Center, Greenbelt, MD (United States) Univ. of California, Los Angeles (United States)
4. Univ. of Alaska, Fairbanks (United States)
5. Univ. of Iowa, Iowa City (United States)
6. Univ. of Calgary, Alberta (Canada)
7. Aerospace Corp., El Segundo, CA (United States)
8. Univ. of Maryland, College Park (United States)
9. Meteorological Research Inst. Ibaraki (Japan)

The ninth Coordinated Data Analysis Workshop focused upon several intervals within the PROMIS period. Event interval C comprised the period 0000-1200 UT on May 3, 1986, which was a highly distrubed time near the end of a geomagnetic storm interval. A very large substorm early in the period commenced at 0111 UT and had a peak AE index value of [approximately]1500 nT. Subsequent activity was lower, but at least three other substorms occurred at 2-3 hour intervals. The substorms on May 3 were well observed by a variety of satellites including ISEE 1,2 and IMP 8 in the magnetotail plus SCATHA, GOES, GMS, and LANL spacecraft at or near geostationary orbit. A particularly important feature of the 0111 UT substorm was the simultaneous imaging of the southern auroral oval by DE 1 and of the northern auroral oval by Viking. The excellent constellation of spacecraft near local midnight in the radial range 5-9 R[sub E] made it possible to study the strong cross-tail current development during the expansion phase. A clear latitudinal separation ([ge]10[degrees]) of the initial region of auroral brightening and the region of intense westward electrojet current was identified. The combined ground, near-tail and imaging data for this event provided an unprecedented opportunity to investigate tail current development, field line mapping, and substorm onset mechanisms. Evidence is presented for strong current diversion within the near-tail plasma sheet during the late growth phase and strong current disruption and field-aligned current formation from deeper in the tail at substorm onset. The authors conclude that these results are consistent with a model of magnetic neutral line formation in the late growth phase which causes plasma sheet current diversion before the substorm onset. The expansion phase onset occurs later due to reconnection of lobelike magnetic field lines and roughly concurrent cross-tail disruption in the inner plasma sheet region. 52 refs., 14 figs. 1 tab.

• OSTI ID: 6873430
• Journal Information: Journal of Geophysical Research; (United States), Vol. 98:A3; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EARTH MAGNETOSPHERE
MAGNETIC STORMS
EXPANSION
MATHEMATICAL MODELS
TIME DEPENDENCE
AURORAE
AURORAL OVAL
DATA ANALYSIS
ELECTROJETS
MAGNETIC FIELDS
MAGNETOTAIL
MAPPING
PLASMA SHEET
SATELLITES
CURRENTS
EARTH ATMOSPHERE
ELECTRIC CURRENTS
661320* - Auroral
Ionospheric
& Magnetospheric Phenomena- (1992-)