Radiometric measurements of electron temperature and opacity of ionospheric perturbations. Issue 2 (18th February 2015)

• Record Type: Journal Article
• Authors: Rogers, A. E. E.; Bowman, J. D.; Vierinen, J.; Monsalve, R.; Mozdzen, T.
• Is Part Of: Radio science. Volume 50:Issue 2(2015:Feb.)
• Page Start: 130
• Page End: 137
• Publication Date: 2015-02-18
• Subjects: ionosphere -- radiometry -- electron temperature; Radio meteorology -- Periodicals; Radio wave propagation -- Periodicals; 621.38405
• DOI: 10.1002/2014RS005599
• Languages: English
• ISSNs: 0048-6604

Abstract

Abstract: Changes in the sky noise spectrum are used to characterize perturbations in the ionosphere. Observations were made at the same sidereal time on multiple days using a calibrated broadband dipole and radio spectrometer covering 80 to 185 MHz. In this frequency range, an ionospheric opacity perturbation changes both the electron thermal emission from the ionosphere and the absorption of the sky noise background. For the first time, these changes are confirmed to have the expected spectral signature and are used to derive the opacity and electron temperature associated with the perturbations as a function of local time. The observations were acquired at the Murchison Radio‐astronomy Observatory in Western Australia from 18 April 2014 to 6 May 2014. They show perturbations that increase at sunrise, continue during the day, and decline after sunset. Magnitudes corresponding to an opacity perturbation of about 1% at 150 MHz with a typical electron temperature of about 800 K were measured for the strongest perturbations. Key Points: A Calibrated broadband spectrometer can measure ionosphere electron temperature The radiometric measurement of the electron temperature agrees with model