Nearly simultaneous images of HF-pump enhanced airglow at 6300 Å and 5577 Å

Abstract

This report presents nearly simultaneous images of HF-pump enhanced airglow at 6300 Å and 5577 Å caused by HF radio wave pumping in the ionosphere from the EISCAT-Heating facility. The images show co-located enhancements implying that there are O(1D) and O(1S) emissions from the ionospheric F region. The maximum enhancement in 6300 Å is 50-60 Rayleighs and the maximum enhancement in 5577 Å is 10-20 Rayleighs for five different HF-pump pulses. The 5577 to 6300 Å intensity ratio of 0.3-0.4 implies that the excitation is caused by a nonthermal electron population.