SuperDARN observations of spectral enhancements excited during an ionospheric heating experiment

Abstract

Observations are reported of undocumented enhancements to the backscattered HF radar spectrum detected by the Kodiak SuperDARN radar during an O-mode heating experiment conducted at the HAARP facility. A total of 27 enhancements were observed, each of which was statistically significant, well correlated with the heater duty cycle, and localized within the heated region above HAARP. Several enhancements are symmetrically spaced around the pump frequency while others occur near electron gyroharmonics. The enhancements are distributed over a frequency range of more than 6.5 MHz and may, we suggest, indicate the presence of Bernstein modes and upper hybrid oscillations stimulated by the HAARP heater. Copyright 2004 by the American Geophysical Union.