Multi-scale observations of magnetotail flux transport during IMF-northward non-substorm intervals

Grocott, A. and Yeoman, T. K. and Milan, S. E. and Amm, O. and Frey, H. U. and Juusola, L. and Nakamura, R. and Owen, C. J. and Rème, H. and Takada, T. (2007) Multi-scale observations of magnetotail flux transport during IMF-northward non-substorm intervals. Annales Geophysicae, 25 (7). pp. 1709-1720. ISSN 0992-7689

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Abstract

Simultaneous observations by the Cluster spacecraft and SuperDARN radars are presented of magnetotail flux transport during northward, but BY-dominated IMF. Two events are discussed, which occurred on 14 August 2004 and 17 September 2005, during intervals of negative and positive IMF BY, respectively. During both intervals the Cluster spacecraft observed isolated bursts of Earthward plasma convection in the central plasma sheet. During the first event, the flows observed by Cluster also had a significant V⊥Y component in the duskward direction, consistent with westward azimuthal flows observed in the midnight sector by the Northern Hemisphere SuperDARN radars. During the second event, Cluster 4 observed a significant dawnward V⊥Y component, again consistent with the Northern Hemisphere SuperDARN observations which revealed eastward azimuthal flow. In this instance, however, Cluster 3 observed a duskward V⊥Y component which was more consistent with the duskward sense of the convection observed by the Southern Hemisphere SuperDARN radars. This implies that Cluster 3 and Cluster 4 were located on different field lines which experienced opposite net azimuthal forces and hence observed oppositely directed convection. These observations are consistent with previous SuperDARN studies of nightside flows under northward IMF and, more importantly, provide the first simultaneous in-situ evidence for a mode of tail reconnection occurring during non-substorm intervals in an asymmetric tail.

Item Type:
Journal Article
Journal or Publication Title:
Annales Geophysicae
Additional Information:
© European Geosciences Union 2007
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1900/1912
Subjects:
ID Code:
67127
Deposited By:
Deposited On:
11 Oct 2013 10:57
Refereed?:
Yes
Published?:
Published
Last Modified:
19 Sep 2020 02:47