Dynamics and characteristics of black aurora as observed by high resolution ground-based imagers and radar
2011 (English)In: International Journal of Remote Sensing, ISSN 0143-1161, E-ISSN 1366-5901, Vol. 32, no 11, 2973-2985 p.Article in journal (Refereed) Published
High-resolution, multi-spectral data from the ground-based low-light auroral imager ASK (Auroral Structure and Kinetics) are used to characterize the fine structure of black aurora. Sixteen events comprising sheared and unsheared black arcs, as well as black patches and rings, constitute the analysed dataset. Simultaneous measurements of emissions caused by high- and low-energy precipitation make it possible to relate the characteristics of different black structures to the energy of the precipitating electrons. The reductions of high-energy particles versus low-energy particles in the black regions compared to the diffuse background are investigated for the different forms of black aurora. Two separate mechanisms have been suggested to cause black aurora. The larger reduction of high-energy precipitation within the fine-scale black structures discussed here favours a magnetospheric mechanism that blocks high-energy electrons from being scattered into the loss cone. European Incoherent SCATter radar (EISCAT) electron density profiles are available for one of the nights, and are compared to the optical measurements.
Place, publisher, year, edition, pages
2011. Vol. 32, no 11, 2973-2985 p.
Remote Sensing, Imaging Science & Photographic Technology
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-24906DOI: 10.1080/01431161.2010.541517ISI: 000293223900003ScopusID: 2-s2.0-79960046158OAI: oai:DiVA.org:kth-24906DiVA: diva2:354132
Updated from accepted to published 24 Jun 2011.
QC 201010302010-09-302010-09-302011-12-01Bibliographically approved