Please use this identifier to cite or link to this item: http://hdl.handle.net/2381/7897
Title: Localized fast flow disturbance observed in the plasma sheet and in the ionosphere
Authors: Nakamura, R.
Amm, O.
Laakso, H.
Draper, N.C.
Lester, M.
Grocott, Adrian
Klecker, B.
McCrea, I.W.
Balogh, A.
Rème, H.
André, M.
First Published: 28-Feb-2005
Publisher: Copernicus Publications on behalf of the European Geosciences Union (EGU)
Citation: Annales Geophysicae, 2005, 23 (2), pp. 553-566.
Abstract: An isolated plasma sheet flow burst took place at 22:02 UT, 1 September 2002, when the Cluster footpoint was located within the area covered by the Magnetometers-Ionospheric Radars-All-sky Cameras Large Experiment (MIRACLE). The event was associated with a clear but weak ionospheric disturbance and took place during a steady southward IMF interval, about 1h preceding a major substorm onset. Multipoint observations, both in space and from the ground, allow us to discuss the temporal and spatial scale of the disturbance both in the magnetosphere and ionosphere. Based on measurements from four Cluster spacecraft it is inferred that Cluster observed the dusk side part of a localized flow channel in the plasma sheet with a flow shear at the front, suggesting a field-aligned current out from the ionosphere. In the ionosphere the equivalent current pattern and possible field-aligned current location show a pattern similar to the auroral streamers previously obtained during an active period, except for its spatial scale and amplitude. It is inferred that the footpoint of Cluster was located in the region of an upward field-aligned current, consistent with the magnetospheric observations. The entire disturbance in the ionosphere lasted about 10min, consistent with the time scale of the current sheet disturbance in the magnetosphere. The plasma sheet bulk flow, on the other hand, had a time scale of about 2min, corresponding to the time scale of an equatorward excursion of the enhanced electrojet. These observations confirm that localized enhanced convection in the magnetosphere and associated changes in the current sheet structure produce a signature with consistent temporal and spatial scale at the conjugate ionosphere.
DOI Link: 10.5194/angeo-23-553-2005
ISSN: 0992-7689
Links: http://hdl.handle.net/2381/7897
Type: Article
Description: This paper was published as Annales Geophysicae, 2005, 23 (2), pp. 553-566. It is also available from http://www.ann-geophys.net/23/553/2005/angeo-23-553-2005.html
Appears in Collections:Published Articles, Dept. of Physics and Astronomy

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