Published in

American Astronomical Society, Astrophysical Journal, 1(644), p. 613-621, 2006

DOI: 10.1086/503544

Links

Tools

Export citation

Search in Google Scholar

Petschek‐Type Reconnection Exhausts in the Solar Wind Well beyond 1 AU:Ulysses

Journal article published in 2006 by J. T. Gosling, S. Eriksson ORCID, R. M. Skoug, D. J. McComas, R. J. Forsyth
This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Red circle
Preprint: archiving forbidden
Red circle
Postprint: archiving forbidden
Green circle
Published version: archiving allowed
Data provided by SHERPA/RoMEO

Abstract

We have identified 91 Petschek-type exhausts associated with local, quasi-stationary magnetic reconnection in the solar wind in plasma and magnetic field data from the Ulysses spacecraft obtained over a wide range of heliocentric distances (1.4–5.4 AU) and latitudes (S79 –N65). The characteristic signature of an exhaust was a brief (minutes) interval of accelerated or decelerated plasma flow within a bifurcated current sheet in which changes in magnetic field and flow velocity were correlated at one edge and anticorrelated at the other. Transitions from outside to inside the exhausts were always slow-mode–like, the exhausts appearing to an observer as encounters with closely spaced, forward-reverse, slow-mode wave (shock) pairs. The exhausts almost universally occurred in low-speed or inter-planetary coronal mass ejection plasma having low proton (<1 and oftenT1) at relatively large shears (90 –180) in the heliospheric magnetic field. Magnetic field strength decreases within the exhausts were highly variable from event to event and were roughly correlated with the magnitude of the local magnetic shears; this indicates the presence of substantial guide fields in at least some of these events. Many of the exhausts occurred at current sheets separating plasma having distinctly different Alfvén speeds and were thus asymmetric. Local exhaust widths at Ulysses varied up to a maximum of $2 ; 10 6 km but statistically did not vary significantly with heliocentric distance. We offer several possible explanations of this observation.