HF-induced Descending Artificial Plasma Layers (DAPLs) are artificially ionized plasma layers with plasma density in excess of that of the F2-peak. They were discovered during HF heating experiments at HAARP where they descended up to 70 km from the initial O mode wave reflection height. The DAPLs were attributed to the ionization of the neutral gas by high-energy electrons accelerated by the artificial ionospheric turbulence. Recently, DAPL formation was reported during the HF-heating experiment at Arecibo by Bernhardt et al. . A model of artificial plasma layers created by the Arecibo HF facility is presented. It shows that Langmuir turbulence due to the HF heating can accelerate part of the ambient photoelectrons to energies above the ionization threshold of the neutral gas, leading to the formation of DAPLs.
The dataset contains data (Excel format) supporting the figures in the published article "Simulations of the generation of energetic electrons and the formation of descending artificial plasma layers during HF-heating at Arecibo" by Eliasson, B., et al., Journal of Geophysical Research (2018).