2 SPACECRAFT OBSERVATIONS OF A RECONNECTION PULSE DURING AN AURORAL BREAKUP

Citation
Aa. Petrukovich et al., 2 SPACECRAFT OBSERVATIONS OF A RECONNECTION PULSE DURING AN AURORAL BREAKUP, J GEO R-S P, 103(A1), 1998, pp. 47-59
Citations number
30
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Geosciences, Interdisciplinary","Astronomy & Astrophysics","Metereology & Atmospheric Sciences",Oceanografhy,"Geochemitry & Geophysics
Journal title
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
ISSN journal
2169-9380 → ACNP
Volume
103
Issue
A1
Year of publication
1998
Pages
47 - 59
Database
ISI
SICI code
2169-9380(1998)103:A1<47:2SOOAR>2.0.ZU;2-T
Abstract
At 1130 UT on November 28, 1995, two spacecraft, Interball-Tail and Ge otail, were in a favorable position to study the plasma sheet activity and an auroral breakup observed on the ground near the spacecraft ion ospheric footpoints. Both spacecraft were near the neutral sheet, and they were nearly aligned along the magnetic meridian, During the auror al breakup observed at the equatorward half of the auroral oval (also registered as an AKR burst at Interball) both spacecraft simultaneousl y detected signatures of a reconnection pulse: The earthward plasma st reaming and magnetic field dipolarization were observed at 12 R-E at I nterball, while the tailward energetic ion beam, then the tailward flo w and the passage of a plasmoid were observed at 28 R-E at Geotail. Th is pulse seem to proceed inside of the plasma sheet closed field lines , in the region of small (similar to 1 nT) background magnetic field a t the neutral sheet. At Interball position the onset of fast earthward ion flow, likely initiated by the reconnection pulse, was followed by other manifestations (dipolarization, enhancements of the magnetic tu rbulence and the energetic particle flux, the intensification of field -aligned currents). Auroral observations showed initial brightening de layed an approximately 1 min after the commencement of the reconnectio n pulse. The auroral intensification was not accompanied by a signific ant magnetic disturbance on the ground, and therefore the event can be classified as the pseudobreakup. We estimate magnetic flux transport characteristics and possible location of the onset region in the plasm a sheet. We conclude that observations during this event are consisten t with the initiation of an auroral breakup by some disturbance (e.g., Alfven wave) generated by the reconnection pulse that commenced in th e neutral sheet at similar to 15 R-E distance.