Open AccessA kinetic perspective on azimuthal variation of magnetopause reconnection at scales below an Earth radius
Author(s) -
Ying Zou,
Brian M. Walsh,
Emil Atz,
Haoming Liang,
Qianli Ma,
V. Angelopoulos
Publication year - 2020
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/1620/1/012028
Subject(s) - magnetosheath , physics , magnetopause , earth radius , magnetic reconnection , population , radius , amplitude , current sheet , astrophysics , computational physics , geophysics , magnetosphere , plasma , magnetohydrodynamics , demography , sociology , computer security , quantum mechanics , computer science
Magnetic reconnection efficiency at the Earth’s magnetopause has recently been shown to exhibit variations in reconnection jet amplitudes at azimuthal scales below an Earth radius [1]. This finding, however, is obtained based on the bulk velocity moment measurements. If there exists a significant cold magnetospheric ion population in addition to the accelerated magnetosheath population, the combination of the two would yield a low bulk velocity moment that does not necessarily correspond to a weak reconnection activity. Here we analyse ion distribution functions of the three reconnection events in [1] to examine whether the varying jet amplitudes are due to the presence of cold magnetospheric ions or variations of reconnection acceleration. Our results show that, although the cold magnetospheric ions have lowered the absolute bulk velocity, the relative variation trend of the bulk velocity is consistent with that of the acceleration gained by magnetosheath ions. The result supports the interpretation that reconnection activity can vary azimuthally on scales below an Earth radius.