Time-dependent magnetic reconnection in two-dimensional periodic geometry
作者:
J. Heerikhuisen,
I.J. D. Craig,
P.G. Watson,
期刊:
Geophysical & Astrophysical Fluid Dynamics
(Taylor Available online 2000)
卷期:
Volume 93,
issue 1-2
页码: 115-142
ISSN:0309-1929
年代: 2000
DOI:10.1080/03091920008203724
出版商: Taylor & Francis Group
关键词: Osculation;X-lines;Reconnection
数据来源: Taylor
摘要:
We compare the predictions of incompressible, analytic reconnection theory with numerical simulations performed using a time-dependent, doubly periodic code. The properties of the simulated current sheets are shown to be in good quantitative agreement with recent planar analytic reconnection solutions based onX-point merging driven by sheared incompressible flows. We conclude that the analytic treatment is not seriously compromised by assuming an open flow geometry and a one-dimensional current layer. The analytic models, when augmented by nonlinear saturation arguments, are also shown to provide resistive scaling laws that accord well with computed merging rates. By way of contrast, we have found no computational evidence for the osculation of separatrices in current sheets, even for the case of classical head-on reconnection in which all shearing flows are absent. We attribute this to the dynamic nature of the simulated current sheet. Our simulations provide some evidence that dynamic current sheets can break up into magnetic islands, but whether this fragmentation can be attributed to the tearing mode instability remains unclear.
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