DEMETER observations of an intense upgoing column of ELF/VLF radiation excited by the HAARP HF heater

D. Piddyachiy (1) , U. S Inan (1) , T. F Bell (1) , N. G Lehtinen (1) , Michel Parrot (2)

1 STAR Lab - Space, Telecommunications, and Radioscience Laboratory
2 LPCE - Laboratoire de physique et chimie de l'environnement

DEMETER spacecraft observations of ELF signals generated by the recently upgraded High-Frequency Active Auroral Research Program (HAARP) HF facility (3.6 MW) reveal three distinctive regions characterizing upgoing ELF waves. These regions are classified by signal intensity and the minimum lateral distance d between the magnetic footprint of the satellite at 75-km altitude (D layer) and the point at 75-km altitude immediately above HAARP where the source is located. The first large region within d ' 900 km contains waves which propagate in the Earth-ionosphere waveguide and then leak upward to the spacecraft. The second region of d ' 200-300 km contains waves propagating to the spacecraft from the ionospheric source region without reflection from the ground. The third region contains waves of very high intensity (E ' 350 mV/m, B ' 20 pT) within a narrow cylindrical column of $10-20 km radius, also observed once before on the ISIS 1 spacecraft. The observed intense columnar radiation is consistent with predictions of a recent full-wave model of ELF radiation from HF-heater-produced ionospheric source currents.

Domains: Sciences of the Universe [physics]

D. Piddyachiy, U. S Inan, T. F Bell, N. G Lehtinen, Michel Parrot. DEMETER observations of an intense upgoing column of ELF/VLF radiation excited by the HAARP HF heater. Journal of Geophysical Research Space Physics, 2008, 113 (A10), ⟨10.1029/2008JA013208⟩. ⟨insu-03037212⟩