Spiral Bingo

clipped from herkules.oulu.fi Ionospheric D-region studies by means of active heating experiments and modelling Antti Kero Faculty of Science, Department of Physical Sciences, University of Oulu Sodankylä Geophysical Observatory, University of Oulu Academic Dissertation to be presented, with the permission of the Faculty of Science of the University of Oulu, for public discussion in Polaria, Sodankylä, on 8th December, 2008, at 12 o’clock noon. Copyright © 2008 University of Oulu UNIVERSITY OF OULU, OULU FINLAND 2008 ISBN 978-951-42-8916-3 (PDF) URN:ISBN:9789514289163 Abstract Powerful radio waves can heat an electron gas via collisions between free electrons and neutral particles. Since the discovery of the Luxembourg effect in 1934, this effect is known to take place in the D-region ionosphere. According to theoretical models, the EISCAT Heating facility is capable of increasing the electron temperature by a factor of 5–10 in the D region, depending mostly on the electron density profile.

Kero and Rapp's EISCAT experiment is here.

UPDATE: See this post. Turns out EISCAT didn't do it.