Optical and Radio Frequency Diagnostics of the Ionosphere over the Sura Facility: Review of Results

Abstract

We give an overview of the design and results of the optical-backscatter-heating campaign which we conducted at the Sura facility near Nizhniy Novgorod, Russia on August 10-20, 2004. This campaign was the first to combine optical observations with simultaneous plasma diagnostics by the method of artificial periodic irregularities and with multi-position backscatter measurements and is an example of the clustering of instruments for the purpose of enhancing research results. Some of the results of the campaign have been published in a special issue of Radiophysics and Quantum Electronics and in Physical Review Letters and will only be summarized here. New results include offset of the optical emissions by 1-2° from magnetic zenith; broadening of the backscatter spectrum for heating at the fourth harmonic of the electron gyro frequency; observation of self-scattered signals at the second harmonic of the heater frequency; first observations of vector plasma drift/electric field measurements using field-aligned irregularities as tracers; verifying the refractive index mechanism for the Doppler shift of self-scattered signals and first observations of synchronized variations in self-scattered and backscattered signals. The electric field observations confirm that the ionosphere over a mid-latitude site such as SURA can be affected by high latitude processes.