Ground-based observations of an onset of localized field-aligned currents during auroral breakup around magnetic midnight
Item
Title (Dublin Core)
en-US
Ground-based observations of an onset of localized field-aligned currents during auroral breakup around magnetic midnight
Description (Dublin Core)
en-US
The substorm on 2 March 1978 was selected for study as a relatively weak substorm, starting at about local magnetic midnight, that could be observed with instruments in Northern Scandinavia. The analysis is based on a comparative study of data from the IMS magnetometer network, all-sky cameras, pulsation magnetometers, and riometers in the Scandinavian area. In addition other data are used to support the results, e.g., a photograph from the DMSP-F2 satellite, showing the auroral situation over Scandinavia, and further west, immediately after the substorm onset. The substorm was preceded by a weak activation of aurora and magnetic disturbance about 3 min before the onset. After a fading that lasted for 20 s and could be observed only in optical aurora, the substorm onset led to a strong brightening of the aurora, an enhancement of the westward electrojet, a sudden rise in the ionospheric D-layer absorption, and Pi B type pulsations. Immediately after the onset, the ground magnetic data suggest the appearence of a pair of oppositely directed, localized, field-aligned currents (FACs). The main development of the signatures of the downward FAC was clearly delayed by about 3 min. There were significant correlations between the magnetic signatures of the two FACs and different features and spectra of the optical aurora, both in time and location. The observed Pi B type pulsations lasted as long as a growth in the local onset-connected FACs could be inferred. Within the first three minutes the localized three dimensional current system developed into a more sheet-like configuration. An expansion to the west, possibly accompanied by a westward travelling surge, was traced with riometers and magnetometers on Iceland and Greenland.
ARK: https://n2t.net/ark:/88439/y084828
Permalink: https://geophysicsjournal.com/article/208
ARK: https://n2t.net/ark:/88439/y084828
Permalink: https://geophysicsjournal.com/article/208
Creator (Dublin Core)
Opgenoorth, H.J.
Pellinen, R.J.
Maurer, H.
Kuppers, F.
Heikkila, W.J.
Kaila, K.U.
Tanskanen, P.
Subject (Dublin Core)
en-US
Auroral substorm
en-US
Magnetic substorm
en-US
Substorm onset
en-US
Field-aligned currents
en-US
Auroral electrojet
en-US
Atmosphere
Publisher (Dublin Core)
en-US
Journal of Geophysics
Date (Dublin Core)
1980-03-27
Type (Dublin Core)
info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
en-US
Peer-reviewed Article
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
https://journal.geophysicsjournal.com/JofG/article/view/208
Source (Dublin Core)
en-US
Journal of Geophysics; Vol 48 No 1 (1980): Journal of Geophysics; 101-115
2643-2986
2643-9271
Language (Dublin Core)
eng
Relation (Dublin Core)
https://journal.geophysicsjournal.com/JofG/article/view/208/168