Mapping of the auroral horn into the magnetotail

Details Mapping of the auroral horn into the magnetotail Mapping of the auroral horn into the magnetotail

Sep 1990

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1990p%26ss...38.1179k&link_type=abstract

Planetary and Space Science (ISSN 0032-0633), vol. 38, Sept. 1990, p. 1179-1186.

Physics

5

Auroral Arcs, Geomagnetic Tail, Magnetic Storms, Boundary Layer Flow, Field Aligned Currents, Magnetic Field Configurations, Traveling Ionospheric Disturbances

Scientific paper

The auroral horn is a frequently observed brightening of a preexisting auroral arc immediately after a substorm onset has taken place. The tip of the horn propagates westward (and sometimes eastward) with a speed of 10-30 km/s in the ionosphere, which is considerably faster than the westward expansion speed of the main auroral bulge. The field-aligned mapping of the horn into the magnetotail is studied using the 1989 version of the Tsyganenko magnetic field model. It is argued that the source of the horn propagates from the location of the substorm onset in the tail current sheet toward the plasma sheet boundary layer. The propagation speed in the tail is larger than a reasonable expansion speed of a current disruption region in the current sheet. A natural fast propagation mode across the tail is a magnetosonic wave, which may interact with kiloelectron volt electrons resulting in enhanced pitch angle scattering into the loss cone and brightening of the auroral luminosity along the horn. Thus the auroral horn may be an expression of communication between the current sheet and the plasma sheet boundary layer shortly after the substorm onset.

Affiliated with

Also associated with

No associations

Rating

Mapping of the auroral horn into the magnetotail does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Mapping of the auroral horn into the magnetotail, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mapping of the auroral horn into the magnetotail will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1406273