MODIFICATIONS OF THE MIDDLE ATMOSPHERE CONDUCTIVITY DURING SUDDEN IONOSPHERE DISTURBANCES AND VARIATIONS OF SCHUMANN RESONANCE FREQUENCIES
MODIFICATIONS OF THE MIDDLE ATMOSPHERE CONDUCTIVITY DURING SUDDEN IONOSPHERE DISTURBANCES AND VARIATIONS OF SCHUMANN RESONANCE FREQUENCIES
Blog Article
The investigation of the effect of space weather on different layers of the terrestrial atmosphere has been and remains a relevant problem of remote sensing of the environment.We describe a technique for detecting modifications of the peak frequencies of the Schumann resonance during the sudden ionospheric disturbances (SID) caused by the solar gotrax handlebar X-ray flares.The SID is associated with a sharp lowering of the ionosphere over sunlit hemisphere during the chromospheric flare.Lowering of the daytime ionosphere reduces the average height of Earth-ionosphere cavity and leads to an increase in Schumann resonance frequencies.
The model of the conductivity profile of the middle atmosphere and its modification is used.The resonance frequencies of the Earth-ionosphere cavity and the characteristic heights of the conductivity profile are calculated by the full wave method for the ionospheric disturbances of different intensity.The power spectra of the vertical electric field are computed using the 2D telegraph equations for the uniform spatial distribution of thunderstorms in the resonator with the day-night non-uniformity at several positions of the observer relative to the solar terminator.The changes in the peak frequencies are obtained depending on the intensity of the ionospheric disturbance.
The weighted average frequency read more of the Schumann resonance is calculated for the first three modes, and, using the least squares method, the parameters of linear dependence of this frequency on the intensity of the SID and/or on the changes of magnetic characteristic height of the conductivity profile are established.The data are suggested to be used as a calibration curve for interpretation of the observational results and estimation of the modification in the lower ionosphere from the Schumann resonance frequencies.