Open AccessExamining the Potential of the Super Dual Auroral Radar Network for Monitoring the Space Weather Impact of Solar X‐Ray Flares
Author(s) -
Fiori R. A. D.,
Koustov A. V.,
Chakraborty S.,
Ruohoniemi J. M.,
Danskin D. W.,
Boteler D. H.,
Shepherd S. G.
Publication year - 2018
Publication title -
space weather
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.254
H-Index - 56
ISSN - 1542-7390
DOI - 10.1029/2018sw001905
Subject(s) - riometer , ionosphere , solar zenith angle , ionospheric absorption , zenith , solar flare , attenuation , physics , radio wave , geology , remote sensing , environmental science , atmospheric sciences , astrophysics , geophysics , optics , quantum mechanics
Increased electron density in the ionosphere due to photoionization by radiation emitted during a solar X‐ray flare impacts high‐frequency (HF) radio wave propagation. Shortwave fadeout (SWF) due to the enhanced D region absorption that results is characterized by the level of cosmic radio noise attenuation derived from riometer measurements. SWF impacts HF radio propagation and has been identified in the Super Dual Auroral Radar Network (SuperDARN) data. An X2.1 solar X‐ray flare that erupted on 11 March 2015 is examined to determine its effects on HF radio propagation. Riometer data indicate a sharp enhancement in absorption, which falls off with increasing solar zenith angle. SuperDARN radars observed a suppression of both ground scatter and ionospheric echoes. Ground scatter data indicated a rapid weakening of signal from far to near ranges followed by a ~20‐min interval of complete signal loss. Recovery lasted ~30 min and proceeded from near to far ranges. Prior to the complete signal loss, an apparent sharp velocity impulse (Doppler flash) lasting 1–2 min was observed in the ground scatter data. The peak of this flash preceded the onset of enhanced absorption. The onset of signal loss by SuperDARN preceded the onset of enhanced absorption observed by riometers. Both data sets observed a positive correlation between increasing delay in onset and increasing solar zenith angle with onset progressing at an average rate of 16.7°/min (0.060 min/°). Agreement between riometer and SuperDARN indicates the possibility of using a joint data set for improved monitoring of the space weather impact of solar X‐ray flares.