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

Journal Article · Mon Jan 03 23:00:00 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, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1320; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

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