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Effects of Cross‐Sheet Density and Temperature Inhomogeneities on Magnetotail Reconnection
Author(s) -
Lu San,
Artemyev A. V.,
Angelopoulos V.,
Pritchett P. L.,
Runov A.
Publication year - 2019
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl081420
Subject(s) - current sheet , magnetic reconnection , substorm , physics , plasmoid , plasma sheet , particle acceleration , outflow , geophysics , current (fluid) , computational physics , magnetosphere , astrophysics , acceleration , magnetohydrodynamics , magnetic field , classical mechanics , meteorology , quantum mechanics , thermodynamics
Properties of magnetic reconnection in Earth's magnetotail are determined by prereconnection current sheet characteristics. Although spacecraft observations have revealed that the spatial profiles of two important parameters, density and temperature, across the prereconnection magnetotail current sheet are inhomogeneous, the effects of the inhomogeneities on reconnection processes have received insufficient attention. Using Time History of Events and Macroscale Interactions during Substorm (THEMIS) and Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) observations, we show that the inhomogeneities are ubiquitous throughout the magnetotail. Using particle‐in‐cell simulations, we demonstrate that strong density inhomogeneity increases magnetotail reconnection rate, and strong temperature inhomogeneity further increases reconnection outflow speed (although reconnection rate does not change significantly). Overall, these inhomogeneities expedite energy conversion efficiency and secondary plasmoid formation during reconnection. As the current sheet density and temperature characteristics vary considerably with geocentric distance and time under different geospace conditions, a large variety of reconnection and postreconnection dynamics results from this dependence.