Comment on Lockwood and Davis, "On the longitudinal extent of magnetopause reconnection pulses"

[摘要] Lockwood and Davis (1996) present a concisedescription of magnetopause reconnection pulses, with the claimed support ofthree types of observations: (1) flux transfer events (FTE), (2) poleward-movingauroral forms on the dayside, and (3) steps in cusp ion dispersioncharacteristics. However, there are a number of errors and misconceptions in thepaper that make their conclusions untenable. They do not properly take accountof the fact that the relevant processes operate in the presence of a plasma.They fail to notice that the source of energy (a dynamo with E · J<0)must be close to the region of dissipation (the electrical load with E ·J>0) in transient phenomena, since energy (or information) cannottravel faster than the group velocity of waves in the medium (here the Alfvénvelocity V_A). In short, Lockwood and Davis use the wrongcontour in their attempt to evaluate the electromotive force (emf). Thiscriticism goes beyond their article: a dynamo is not included in the usualdefinition of reconnection, only the reconnection load. Without an explicitsource of energy in the assumed model, the idea of magnetic reconnection isimproperly posed. Recent research has carried out a superposed epoch analysis ofconditions near the dayside magnetopause and has found the dynamo and the load,both within the magnetopause current sheet. Since the magnetopause current isfrom dawn to dusk, the sign of E · J reflects the sign of theelectric field. The electric field reverses, within the magnetopause; this canbe discovered by an application of Lenz's law using the concept of erosion ofthe magnetopause. The net result is plasma transfer across the magnetopause tofeed the low latitude boundary layer, at least partly on closed field lines, andviscous interaction as the mechanism by which solar wind plasma couples to themagnetosphere.

[学科分类] 地球科学(综合)