Broad current sheets, current bifurcation, and collisionless reconnection — An Opinion on “Onset of fast magnetic reconnection via subcritical bifurcation” by Z. Guo and X. Wang

We comment on a recently published paper which proposed ion-acoustic wave driven current bifurcation in moderately broad current sheets as cause of collisionless reconnection. Such current sheets are stable with respect to ion-acoustic or Buneman modes and hence the mechanism cannot work in the present form. However, lower-hybrid drift instability may replace the ion-acoustic instability and cause current bifurcation as observed in Earth's magnetotail. This does not lead to reconnection. Nonetheless, the proposal of the bifurcation mechanism is of interest also for the reason that it demonstrates that high temperature plasmas might undergo phase transition.

@article{id2091,
  author = {Treumann, R.A. and Baumjohann, W.},
  doi = {10.3389/fphy.2015.00040},
  journal = {Frontiers in Physics},
  language = {en},
  note = {1 Figure, OPEN ACCESS},
  pages = {1-4},
  title = {Broad current sheets, current bifurcation, and collisionless reconnection {\textemdash} An Opinion on {\textquotedblleft}Onset of fast magnetic reconnection via subcritical bifurcation{\textquotedblright} by Z. Guo and X. Wang},
  volume = {3},
  year = {2015},
}

%O Journal Article
%A Treumann, R.A.
%A Baumjohann, W.
%R 10.3389/fphy.2015.00040
%J Frontiers in Physics
%G en
%O 1 Figure, OPEN ACCESS
%P 1-4
%T Broad current sheets, current bifurcation, and collisionless reconnection — An Opinion on “Onset of fast magnetic reconnection via subcritical bifurcation” by Z. Guo and X. Wang
%V 3
%D 2015