I think that the HAARP in Norway is a good explanation, since you can even see a beam being projected from the ground at some points on the videos. Ever wondered why there was such a worldwide push to get TV off the UHF and VHF frequencies? The very same frequencies used by these high power antennas.

"EISCAT (European Incoherent Scattter) studies the interaction between the Sun and the Earth as revealed by disturbances in the magnetosphere and the ionised parts of the atmosphere (these interactions also give rise to the spectacular aurora, or Northern Lights)."

"One EISCAT transmitter site consisting of a UHF system and a VHF system is located close to the city of Tromsø, in Norway"
[link to e7.eiscat.se]

"Active ionospheric research facilities like HAARP attempt to produce small temporary changes in a limited region directly over the facility which, in no way, compare to the worldwide events frequently caused by the sun. But the extraordinary suite of sensitive observational instruments installed at observatories like HAARP permit a detailed and comprehensive correlation with the induced effects, resulting in new insights into the ways the ionosphere responds to a much wider variety of natural conditions."

I really don't think they can be making such a statement when they do not even understand how the sun-earth link works and all the complicated processes that occur in the atmosphere above us.

"In the Auroral latitudes, the ionosphere carries a current that may reach magnitudes up to or beyond a million amperes. This current, which is called the auroral electrojet, can change in dramatic ways under solar influence, and, when it does, currents can be induced in long terrestrial conductors like power lines and pipe lines. While such effects found in nature cannot be reproduced by active ionospheric research, the sensitive instruments at observatories like HAARP can follow the progress of natural magnetic storms and provide insight into the physical mechanisms at work in the ionosphere."

They keep saying HAARP is only to measure and probe the ionosphere.
[link to www.haarp.alaska.edu]

VHF signals with frequencies above about 30 MHz usually penetrate the ionosphere and are not returned to the Earth's surface. E-skip is a notable exception, where VHF signals including FM broadcast and VHF TV signals are frequently reflected to the Earth during late Spring and early Summer. E-skip rarely affects UHF frequencies, except for very rare occurrences below 500 MHz.

Frequencies below approximately 10 MHz (wavelengths longer than 30 meters), including broadcasts in the mediumwave and shortwave bands (and to some extent longwave), propagate most efficiently by skywave at night. Frequencies above 10 MHz (wavelengths shorter than 30 meters) typically propagate most efficiently during the day. Frequencies lower than 3 kHz have a wavelength longer than the distance between the Earth and the ionosphere. The maximum usable frequency for skywave propagation is strongly influenced by sunspot number.

Skywave propagation is usually degraded -- sometimes seriously -- during geomagnetic storms. Skywave propagation on the sunlit side of the Earth can be entirely disrupted during sudden ionospheric disturbances.

Because the lower-altitude layers (the E-layer in particular) of the ionosphere largely disappear at night, the refractive layer of the ionosphere is much higher above the surface of the Earth at night. This leads to an increase in the "skip" or "hop" distance of the skywave at night.
[link to en.wikipedia.org]

Aurora occur at about 100 KM in the atmosphere, I don't know how far up the "anomaly" in Norway was, but if it was HAARP or the radar then it could only create plasma where there is hot gas and electricity. If this was lower then the usual place for aurora and other electrical/plasma phenomena they would have to create their own plasma. Luckily nowdays we have powerful lasers than can heat up, with almost pinpoint accuracy, any part of our sky. The hard part would be the current.