TITLE:
The Pattern of By Deflections Produced from Field-Aligned Currents Earthward of the Activation Source in the Earth’s Magnetosphere
AUTHORS:
Dimitrios V. Sarafopoulos
KEYWORDS:
Magnetic Reconnection, Magnetic Flux Rope in Magnetotail, Field-Aligned Currents, Plasma Sheet, Double Layers
JOURNAL NAME:
International Journal of Geosciences,
Vol.7 No.4,
April
21,
2016
ABSTRACT: In this investigation
effort, we eventually infer that the overall quadrapole pattern of By deflections, in the vicinity of a
source in the Earth’s magnetotail, is most likely due to field aligned currents
(FACs) and not to Hall currents associated with an X-type collisionless
reconnection. This categorically
expressed statement is based upon sufficient observational evidence tightly
associated with our own suggested model and the preceded works of the same
author. Using representative
events measured by satellite, our main aim is to describe the nature of the
fundamental mechanism determining the polarity of the By deflections associated with intense
earthward ionplasma flows. A major finding is that we either observe magnetic
flux rope (MFR) like structures (that is, entities having all the morphological
features of ropes;i.e., a dipolar signature of Bz occurring simultaneously with peaked By and Btotal deflections) or mere By deflections, however, the sign for all these (Bydeflections) is always determined by the satellite
placement in north (positive) or south (negative) plasma sheet. Therefore, the
MFR-like structures located earthward of the source are most likely
pseudo-MFRs; there is neither a
tubular topology nor an axial magnetic field, the By deflections are produced by FACs. According to the presented model, a
fundamental concept is that both ions and electrons are simultaneously
accelerated at the source site; in turn, the earthward streaming electrons
(ions) form a bifurcated electron (ion) FAC just outside the electron diffusion
region-EDR (IDR). In this way, inside the IDR (and earthward of the source)
positive (negative) By deflections
in north (south) plasma sheet (PS) are produced due to FACs, and not to
(inward) Hall currents as in the context of an X-line. Moreover, the ions form
an “ion jet” within the IDR, while just outside this region they produce
positive (negative) By deflections
in north (south) PS caused by ion FACs. The ion jet in the IDR is enveloped by
the bifurcated electron FAC. Eventually, although the resulting pattern of By deflections, due to both electron and
ion FACs, is apparently the same with that resulting from Hall currents (in the
X-line model), the underlying natural processes are, however, radically
different. Certainly, the dominant “spatial entity” within the IDR is the ion
jet-current (and not the Hall-electron current). Additional implications of the
ion jets are also discussed.