Features of small-scale artificial irregularities in the high latitude ionospheric F-region from remote sensing observations
Year: 2025
Type: article
Abstract: Powerful HF radio waves interacting with the ionosphere accelerate or heat electrons, pushing the ionospheric plasma out of equilibrium and leading to the creation of various non-linear phenomena. One of the most prominent phenomena discovered from HF heating experiments is the generation of small-scale artificial field-aligned irregularities (AFAI). AFAI induce bi-static scattering of HF and VHF signals, providing their propagation in the frequency range and over distances unattainable in the natural ionosphere. This makes it possible to create HF-driven radio communication channels. We present results from an EISCAT/Heating (Tromsø, Norway) experiment on 18 February 2013, concerning the features and behaviors of AFAI in the high latitude ionospheric F-region induced by high power HF radio waves with O- and X-mode polarization using the bi-static scatter method. Joint use of various remote diagnostics tools, including the multichannel HF Doppler equipment, oblique sounding and the CUTLUSS backscatter radar provides a more comprehensive and complete AFAI study, including the size of the artificially disturbed region occupied with AFAI, the frequency band of bi-static scatter signals (BSS), the fine structure of BSS, the intensity, growth and decay times of AFAI. It has been found that O- and X-mode AFAI have different characteristics and generation mechanisms.
Source: Arctic and Antarctic Research
Institution: Arctic and Antarctic Research Institute
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
OpenAlex ID: W4408991945