Is Quadrupole Structure of Out-of-Plane Magnetic Field Evidence for Hall Reconnection?

Journal Article · Tue Jan 04 00:00:00 EST 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3544318· OSTI ID:21510077

Karimabadi, H; Vu, H X; Loring, B; Omelchenko, Y ^[1]; Dorelli, J ^[2]

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1. Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA (United States)
2. NASA Goddard Space Flight Center, Greenbelt, MD (United States)

The experimental observation of a quadrupole pattern in the ''out-of-plane'' field B{sub y} is usually interpreted as a tell-tale sign of Hall MHD mediated magnetic reconnection in the vicinity of a reconnecting X-point. In contrast to these conventional expectations, it is shown B{sub y} means of analytical equations describing the generation of B{sub y} that quadrupole structure can be formed even in the absence of Hall effects. In general, B{sub y} can be generated due to inhomogeneous ion flow, inhomogeneous current (Hall effect), or terms proportional to a pre-existing B{sub y}. This prediction is validated in a 3D global MHD simulation where it is shown that vortex flows at the dayside magnetopause lead to formation of a finite B{sub y} even in the absence of a pre-existing IMF B{sub y}. The generated field is shown to have a quadrupolar pattern in B{sub y} with peak amplitude {approx}0.5 of the total field. Similar vortex flows are also observed in 3D global hybrid simulations but the resulting B{sub y} structure in this case is a combination of the Hall effects and the inhomogeneous ion flows. Thus special care must be taken in using observations of quadrupole B{sub y} in satellite and experiments to infer information about its particular generation mechanism or attributing it to the Hall MHD reconnection regime.

• OSTI ID: 21510077
• Journal Information: AIP Conference Proceedings, Vol. 1320, Issue 1; Conference: Festschrift on modern challenges in nonlinear plasma physics: Honoring the career of Dennis Papadopoulos, Halkidiki (Greece), 15-19 Jun 2010; Other Information: DOI: 10.1063/1.3544318; (c) 2010 American Institute of Physics; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
FORECASTING
HALL EFFECT
HYDROMAGNETIC WAVES
IONS
MAGNETIC FIELDS
MAGNETIC RECONNECTION
MAGNETOHYDRODYNAMICS
MAGNETOPAUSE
PEAKS
QUADRUPOLES
SATELLITES
SIMULATION
THREE-DIMENSIONAL CALCULATIONS
VORTEX FLOW
CHARGED PARTICLES
FLUID FLOW
FLUID MECHANICS
HYDRODYNAMICS
MECHANICS
MULTIPOLES