Artificial Ionospheric Plasma Clouds (image) Naval Research Laboratory Caption This is a sequence of images of the glow plasma discharge produced with transmissions at the third electron gyro harmonic using the HAARP HF transmitter, Gakona, Alaska. The third harmonic artificial glow plasma clouds were obtained with HAARP using transmissions at 4.34 megahertz (MHz). The resonant frequency yielded green line (557.7 nanometer emission) with HF on November 12, 2012, between the times of 02:26:15 to 02:26:45 GMT. Credit SRI International - Elizabeth Kendall Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.