The University of Southampton
University of Southampton Institutional Repository

Co-existing structures from high and low energy precipitation in fine scale aurora

Dahlgren, H., Lanchester, B.S. and Ivchenko, N. (2015) Co-existing structures from high and low energy precipitation in fine scale aurora Geophysical Research Letters (doi:10.1002/2015GL063173).

Record type: Article


High resolution multi-monochromatic measurements of auroral emissions have revealed the first optical evidence of coexisting small-scale auroral features resulting from separate high and low energy populations of precipitating electrons on the same field line. The features exhibit completely separate motion and morphology. From emission ratios and ion chemistry modeling, the average energy and energy flux of the precipitation is estimated. The high energy precipitation is found to form large pulsating patches of 0.1 Hz with a 3 Hz modulation, and non-pulsating co-existing discrete auroral filaments. The low energy precipitation is observed simultaneously on the same field line as discrete filaments with no pulsation. The simultaneous structures do not interact, and they drift with different speeds in different directions. We suggest that the high and low energy electron populations are accelerated by separate mechanisms, at different distances from earth. The small scale structures could be caused by local instabilities above the ionosphere.

PDF highElowE_GRL_postrevision_ePrint.pdf - Accepted Manuscript
Download (3MB)

More information

Accepted/In Press date: 6 February 2015
e-pub ahead of print date: 10 February 2015
Keywords: aurora, fine scale structure, multispectral observations, high energy precipitation, low energy precipitation, pulsations
Organisations: Astronomy Group


Local EPrints ID: 374583
ISSN: 0094-8276
PURE UUID: 92150d40-58c9-4d28-8197-b321d3e02d50

Catalogue record

Date deposited: 23 Feb 2015 14:06
Last modified: 17 Jul 2017 21:26

Export record



Author: H. Dahlgren
Author: B.S. Lanchester
Author: N. Ivchenko

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton:

ePrints Soton supports OAI 2.0 with a base URL of

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.