HR: 13:30h
AN: SM33A-01 [Abstracts]
TI: Magnetic Disconnection From the Sun: Observations of a Reconnection Exhaust in the Solar Wind at the Heliospheric Current Sheet
AU: * Gosling, J T
EM: jgosling@lanl.gov
AF: Los Alamos National Laboratory, MS D466, Los Alamos, NM 87545 United States
AU: Skoug, R M
EM: rskoug@lanl.gove
AF: Los Alamos National Laboratory, MS D466, Los Alamos, NM 87545 United States
AU: McComas, D J
EM: DMcComas@swri.edu
AF: Southwest Research Institute, Space Science and Engineering Division
P.O. Drawer 28510, San Antonio, TX 78228--510 United States
AU: Smith, C W
EM: chuck@briaxa.sr.unh.edu
AF: University of New Hampshire, Institute for Earth, Oceans and Space
Room 207 Morse Hall
39 College Road, Durham, NH 03824 United States
AB:
We have recently obtained direct evidence for local, quasi-stationary, magnetic reconnection in the solar wind using plasma
and magnetic field data obtained by the Advanced Composition Explorer, ACE. The prime evidence consists of intervals of
accelerated or decelerated plasma flow observed within magnetic field reversal regions that we interpret as encounters with
(generic) Petschek-type reconnection exhausts that are bounded by Alfven waves. Only 1 out of 42 reconnection exhausts
observed by ACE was associated with a crossing of the heliospheric current sheet, HCS, separating open field lines of
opposite magnetic polarity. During that singular event, which corresponded to an encounter with the anti-sunward-directed
exhaust from a reconnection site that initially lay sunward of the spacecraft, the solar wind electron strahl vanished and
the halo electrons interpenetrated from opposite sides of the HCS. These observations demonstrate that magnetic field lines
within and immediately surrounding the exhaust were disconnected from the Sun, as expected. More broadly, these observations
conclusively demonstrate that strahl dropouts observed in the vicinity of the HCS at least at times are signatures of
magnetic disconnection from the Sun.
DE: 2109 Discontinuities
DE: 2134 Interplanetary magnetic fields
DE: 2164 Solar wind plasma
DE: 7835 Magnetic reconnection
SC: SPA-Magnetospheric Physics [SM]
MN: 2005 Joint Assembly