Studies of the ionospheric turbulence excited by the fourth gyroharmonic at HAARP

A. Najmi, G. Milikh, Y. M. Yampolski, A. V. Koloskov, A. A. Sopin, A. Zalizovski, P. Bernhardt, S. Briczinski, C. Siefring, K. Chiang, Y. Morton, S. Taylor, A. Mahmoudian, W. Bristow, M. Ruohoniemi, K. Papadopoulos

Research output: Contribution to journalArticlepeer-review

10 Scopus citations


A study is presented of artificial ionospheric turbulence (AIT) induced by HF heating at High Frequency Active Auroral Research Program (HAARP) using frequencies close to the fourth electron gyroharmonic, in a broad range of radiated powers and using a number of different diagnostics. The diagnostics include GPS scintillations, ground-based stimulated electromagnetic emission (SEE), the HAARP ionosonde, Kodiak radar, and signals received at the Ukrainian Antarctic Station (UAS). The latter allowed analysis of waves scattered by the AIT into the ionospheric waveguide along Earth's terminator, 15.6 mm from the HAARP facility. For the first time, the amplitudes of two prominent SEE features, the downshifted maximum and broad upshifted maximum, were observed to saturate at ~50% of the maximum HAARP effective radiated power. Nonlinear effects in slant total electron content, SEE, and signals received at UAS at different transmitted frequencies and intensities of the pump wave were observed. The correlations between the data from different detectors demonstrate that the scattered waves reach UAS by the waveguide along the Earth's terminator, and that they were injected into the waveguide by scattering off of artificial striations produced by AIT above HAARP, rather than via direct injection from sidelobe radiation.

Original languageEnglish (US)
Pages (from-to)6646-6660
Number of pages15
JournalJournal of Geophysical Research: Space Physics
Issue number8
StatePublished - Aug 1 2015

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Space and Planetary Science


Dive into the research topics of 'Studies of the ionospheric turbulence excited by the fourth gyroharmonic at HAARP'. Together they form a unique fingerprint.

Cite this