"Scientists in Alaska Attempt to Produce Artificial Aurora"
IEEE Spectrum Tech Blog article on the first UAF HAARP research campaign (September 2017)
In order to create an artificial Aurora, it is necessary to induce resonance of plasma. To this purpose, electron resonance must be induced that will trigger electron acceleration and artificial
ionization of atmospheric layers. The plasma resonance condition is found close to the electron gyro-frequency which is approximately 1.4 MHz. However, it is technically difficult to use this value
due to the inherent features of the ionosphere (plasma density is changing, height varies and as a result the magnetic field strength changes). It is proven that using the second harmonic of the
electron gyro-frequency provides very good results (cf. study of plasma instabilities such as parametric decay instability for Langmuir, upper-hybrid, and electron Bernstein waves). This is estimated
to be approximately 2.6–2.7 MHz. Using this condition, electron acceleration is induced and descending artificial ionization layers of the atmosphere are created. We use the term "heating" of