Observation of pulsating aurora signatures in cosmic noise absorption data

A paper was recently accepted for publication in Geophysical Research Letters. It presents the results of a comparison between optical data from an all-sky camera and cosmic noise absorption data measured by KAIRA above Kilpisjärvi, during a pulsating aurora event. 

The accepted version of this article can presently be accessed here; the preliminary reference is:

Grandin, M., A. Kero, N. Partamies, D. McKay, D. Whiter, A. Kozlovsky, and Y. Miyoshi (2017), Observation of pulsating aurora signatures in cosmic noise absorption data, Geophys. Res. Lett., doi:10.1002/2017GL073901.

Abstract
This study investigates the contribution of energetic (E > 30 keV) particle precipitation during a pulsating aurora event over Kilpisjärvi (L = 6.2) on 26 February 2014. It is based on the comparison of auroral blue-line emission (427.8 nm) data from an all-sky camera and cosmic noise absorption (CNA) data obtained from a multi-beam experiment of the Kilpisjärvi Atmospheric Imaging Receiver Array (KAIRA) riometer. The data sets are compared for three KAIRA beams close to magnetic zenith. Results show a clear correlation between the measured CNA and the auroral blue-line emission during the event, for each beam. In addition, individual pulsations are observed for the first time in the CNA data measured by KAIRA, and are found to be close-to-identical to the optical pulsations. This suggests that the modulation of electron precipitation during pulsating aurora takes place in a consistent way over a broad range of energies.