Statistical relationships between cosmic radio noise absorption and ionospheric electrical conductances in the auroral zone

• Published in: Journal of Geophysical Research: Space Physics
• Main Authors: Senior, Andrew, Kavanagh, Andrew J., Kosch, Mike J., Honary, Farideh
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2007
• Subjects: Pedersen; Tromso; EISCAT
• Online Access: https://eprints.lancs.ac.uk/id/eprint/4470/; https://eprints.lancs.ac.uk/id/eprint/4470/1/2007JA012519.pdf; https://doi.org/10.1029/2007JA012519

Statistical models expressing the Hall and Pedersen conductances and their ratio as functions of cosmic noise absorption (CNA) are derived for five intervals of magnetic local time. The models are based on simultaneous measurements of electron densities from the EISCAT UHF radar at Tromso (69.6 N, 19.2 E) and absorption from the imaging riometer at Kilpisjarvi (69.1 N, 20.8 E). The Hall conductance and the conductance ratio are found to be rather strongly related to CNA, whereas the Pedersen conductance is less so. The Hall conductance-CNA relationship is strongly dependent on magnetic local time. These results are interpreted as being the consequence of the particular sensitivity of CNA to the typical energy of electron precipitation, the latter changing as a function of local time as the electrons drift around the Earth. The models are compared to a previous study which did not use simultaneous measurements or take into account the local time dependence. There is a significant difference between that study and the results presented here.