World Library  


Add to Book Shelf
Flag as Inappropriate
Email this Book

The Exterior Cusp and Its Boundary with the Magnetosheath: Cluster Multi-event Analysis : Volume 22, Issue 8 (07/09/2004)

By Lavraud, B.

Click here to view

Book Id: WPLBN0003979148
Format Type: PDF Article :
File Size: Pages 16
Reproduction Date: 2015

Title: The Exterior Cusp and Its Boundary with the Magnetosheath: Cluster Multi-event Analysis : Volume 22, Issue 8 (07/09/2004)  
Author: Lavraud, B.
Volume: Vol. 22, Issue 8
Language: English
Subject: Science, Annales, Geophysicae
Collections: Periodicals: Journal and Magazine Collection, Copernicus GmbH
Historic
Publication Date:
2004
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

Citation

APA MLA Chicago

Escoubet, C. P., Lavraud, B., Sauvaud, J., Dandouras, I., Rème, H., Cargill, P. J.,...Fazakerley, A. (2004). The Exterior Cusp and Its Boundary with the Magnetosheath: Cluster Multi-event Analysis : Volume 22, Issue 8 (07/09/2004). Retrieved from http://members.worldlibrary.net/


Description
Description: Centre d’Etude Spatiale des Rayonnements, Toulouse, France. We report on the observation of three high-altitude cusp crossings by the Cluster spacecraft under steady northward IMF conditions. The focus of this study is on the exterior cusp and its boundaries. At the poleward edge of the cusp, large downward jets are present; they are characterized by a dawn-dusk component of the convection velocity opposite to the IMF By direction and a gradual evolution (velocity filter effect) corresponding to an injection site located at the high-latitude magnetopause tailward of the cusp, with subsequent sunward convection. As one moves from the poleward edge into the exterior cusp proper, the plasma gradually becomes stagnant as the result of the mirroring and scattering of the aforementioned plasma flows. The existence of such a stagnant region (Stagnant Exterior Cusp: SEC) is found in all events studied here even when the IMF By is large and the clock angle is ~90°. The SEC-magnetosheath boundary appears as a spatial structure that has a normal component of the magnetic field pointing inward, in accordance with a probable connection between the region and the magnetosheath (with northward field). This boundary generally has a deHoffmann-Teller velocity that is slow and oriented sunward and downward, compatible with a discontinuity propagating from a location near the high-latitude magnetopause. Although the tangential stress balance is not always satisfied, the SEC-magnetosheath boundary is possibly a rotational discontinuity. Just outside this boundary, there exists a clear sub-Alfvénic plasma depletion layer (PDL). These results are all consistent with the existence of a nearly steady reconnection site at the high-latitude magnetopause tailward of the cusp. We suggest that the stability of the external discontinuity (and of the whole region) is maintained by the presence of the sub-Alfvénic PDL. However, examination of the electron data shows the presence of heated electrons propagating parallel to the magnetic field (upward) just outside of the SEC-magnetosheath boundary. This appears inconsistent with their source being the northern lobe reconnection site. Finally, the definition of the magnetopause at high latitudes is revisited. To define the SEC-magnetosheath boundary as the magnetopause would lead to the misnaming of the exterior cusp.

Summary
The exterior cusp and its boundary with the magnetosheath: Cluster multi-event analysis


 

Click To View

Additional Books


  • Detection of a Plasmaspheric Wind in the... (by )
  • Relativistic Transformation of Phase-spa... (by )
  • Multi-spacecraft Measurement of Anisotro... (by )
  • Average Auroral Configuration Parameteri... (by )
  • Lower E-region Echoes Over the Magnetic ... (by )
  • A Theoretical Verification of Intensity ... (by )
  • First Observation of an Undular Mesosphe... (by )
  • Space Weather Effects on the Magion-4 an... (by )
  • Influences on the Radius of the Auroral ... (by )
  • An Empirical Model of the Auroral Oval D... (by )
  • Concerning the Generation of Geomagnetic... (by )
  • Size of the Coming Solar Cycle 24 Based ... (by )
Scroll Left
Scroll Right

 



Copyright © World Library Foundation. All rights reserved. eBooks from World Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.