A CLUSTER INVESTIGATION OF THE OCCURRENCE AND CAUSES OF RECONNECTION IN THE VERY NEAR-EARTH TAIL (X $> -19$Re)

HR: 08:00h
AN: SM31A-01 [PDF]
TI: A CLUSTER INVESTIGATION OF THE OCCURRENCE AND CAUSES OF RECONNECTION IN THE VERY NEAR-EARTH TAIL (X $> -19$Re)
AU: * Slavin, J A
EM: james.a.slavin@nasa.gov
AF: NASA GSFC, Laboratory for Extraterrestrial Physics, Greenbelt, MD 20771 United States
AU: Tanskanen, E
EM: eija.tanskanen@nasa.gov
AF: NASA GSFC, Laboratory for Extraterrestrial Physics, Greenbelt, MD 20771 United States
AU: Imber, S
EM: suzanne.imber@nasa.gov
AF: Imperial College, Space and Atmospheric Physics, London, SW7 2BZ United Kingdom
AU: Szabo, A
EM: adam.szabo@nasa.gov
AF: NASA GSFC, Laboratory for Extraterrestrial Physics, Greenbelt, MD 20771 United States
AU: Owen, C J
EM: cjo@mssl.ucl.ac.uk
AF: Mullard Space Science Laboratory, Holmbury St. Mary, Dorking, Surrey United Kingdom
AU: Dunlop, M W
EM: m.dunlop@ic.ac.uk
AF: Rutherford-Appelton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX United Kingdom
AU: Lucek, E
EM: e.lucek@ic.ac.uk
AF: Imperial College, Space and Atmospheric Physics, London, SW7 2BZ United Kingdom
AU: Balogh, A
EM: a.balogh@ic.ac.uk
AF: Imperial College, Space and Atmospheric Physics, London, SW7 2BZ United Kingdom
AU: Fornacon, K -
EM: k-h.fornacon@tu-bs.de
AF: Technische Universitд Braunschweig, Institut f〉 Geophysik und Meteorologie, Braunschweig, D-38106 Germany
AB: The Cluster spacecraft cross the plasma sheet at distances of X ~ -16 to -19 Re, significantly earthward of the mean X-line location of ~ -25 Re determined by Geotail. Indeed, transport in the plasma sheet observed by Cluster is usually directed sunward during both quiescent and active intervals. Cluster's polar orbit is ideally suited for the detection of traveling compression regions (TCRs) in the tail lobes and, to a lesser extent, flux ropes in the plasma sheet. TCRs are caused by the rapid motion of flux ropes embedded in high-speed plasma sheet flows generated by multiple X-line reconnection. Hence, they can be used to remotely sense the movement of flux ropes and the plasma sheet flows in which they are embedded. Cluster fluxgate magnetometer measurements taken during the 2001 and 2002 tail seasons have been used to identify and analyze flux rope motion in the near-tail. Earthward moving flux ropes, detected either in situ or remotely as TCRs, are found to outnumber tailward moving flux ropes by a ratio of ~ 3 to 1. Here we investigate the interplanetary and magnetospheric conditions associated with the production of tailward moving flux ropes at Cluster and, by implication, X-line formation in the very near-tail (i.e., X $> -19$ Re). The results will be discussed in terms of the processes leading to plasma sheet thinning and current sheet filamentation.
DE: 2700 MAGNETOSPHERIC PHYSICS
DE: 2799 General or miscellaneous
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting