HR: 14:00h
AN: SM53C-01 INVITED     [Abstracts]
TI: Magnetic Reconnection in the Solar Wind: An Overview
AU: * Gosling, J T
EM: jack.gosling@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics University of Colorado, 1234 Innovation Drive, Boulder, CO 80303, United States
AB: We have recently demonstrated that local, quasi-stationary reconnection occurs relatively frequently in the solar wind over a large range (0.3 to 5.4 AU) of heliocentric distances. Direct evidence for such reconnection is found in the observation of Petschek-type exhausts, i.e., exhausts of jetting plasma bounded by Alfven or slow mode waves, emanating from reconnection sites. The exhausts are identified as intervals of roughly Alfvenic accelerated plasma flow confined to magnetic field reversal regions that usually take the form of bifurcated current sheets. The exhausts are observed almost exclusively in either the low-speed wind or in association with ICMEs in plasma predominantly having low proton beta. Field shears across the exhausts range from about 60 to 180 degrees, indicating the presence of significant guide fields in many of these events. The exhausts are embedded within the solar wind flow and typically are convected past a spacecraft on time scales ranging up to several tens of minutes, although considerably broader events have been observed on occasion. Multi-spacecraft observations have provided convincing evidence that the exhausts commonly result from prolonged reconnection at extended and continuous reconnection sites (X-lines). A relatively minor fraction of the exhausts occur at the heliospheric current sheet, HCS, but observations at the HCS are particularly useful for demonstrating magnetic field topology changes associated with reconnection and the effects of particle and plasma interpenetration within the exhausts. Although the exhausts are characterized by bulk plasma acceleration, we have not yet found any evidence for additional particle acceleration in these events.
DE: 7811 Discontinuities (2109)
DE: 7835 Magnetic reconnection (2723, 7526)
DE: 7846 Plasma energization
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly