HF-induced airglow at magnetic zenith: theoretical considerations
- 1Boston College, Institute for Scientific Research, Chestnut Hill, Massachusetts, USA
- 2Air Force Research Laboratory, Space Vehicles Directorate, Hanscom Air Force Base, MA 01731, USA
Abstract. Observations of airglow at 630nm (red line) and 557.7nm (green line) during HF modification experiments at the High Frequency Active Auroral Research Program (HAARP) heating facility are analyzed. We propose a theoretical framework for understanding the generation of Langmuir and ion acoustic waves during magnetic zenith injections. We show that observations of HF-induced airglow in an underdense ionosphere as well as a decrease in the height of the emitting volume are consistent with this scenario.