Estimating the contribution from different ionospheric regions to the TEC response to the solar flares using data from the international GPS network

This paper proposes a new method for estimating the contribution from different ionospheric regions to the response of total electron content variations to the solar flare which uses the effect of partial shadowing of the atmosphere by the terrestrial globe. The study uses GPS stations located near the boundary of the shadow on the ground in the nightside hemisphere. The beams between the satellite-borne transmitter and the receiver on the ground for these stations pass partially through the atmosphere lying in the region of total shadow and partially through the illuminated atmosphere. The analysis of the ionospheric effect of a powerful solar flare of class X5.7/3B that was recorded on July 14, 2000 (10:24 UT, N22W07) in quiet geomagnetic conditions (Dst=-10 nT) has shown that about 20% of the TEC increase correspond to the ionospheric region lying below 100 km, about 5% refer to the ionospheric E-region (100-140 km), about 30% correspond to the F1-region (140-200 km), and about 30% to regions lying above 300 km.Comment: LaTeX, 6 pages, 4 figures, 1 tabl

The 630 nm and 557.7 nm Airglow During HF Ionosphere Pumping by the SURA Facility Radiation for Pump Frequencies Near the Fourth Electron Gyroharmonic

© 2015, Springer Science+Business Media New York. We present the results of analysis of the dependence of the ionospheric airglow in the red (630 nm) and green (557.7 nm) lines of atomic oxygen on the pump-wave frequency f0 near the fourth electron gyroharmonic 4fce. The experimental data were obtained in 2012 using the SURA heating facility. Stimulated electromagnetic emission spectra were used to determine the relation between f0 and 4fce. It is found that at f0 > 4fce and δf = f0 − 4fce ≈ 15–20 kHz the red-line airglow intensity is about a factor of 1.5 higher for the magnetic zenith pumping (when the pump beam is inclined 12° south of the magnetic field direction) than for the vertical pumping. In the green line for the same offsets δf, the airglow was recorded with confidence only during magnetic zenith pumping. During vertical pumping, no regular dependence of the red-line airglow intensity on δf in the range −15 < δf < 280 kHz was obtained, while the green-line airglow was observed at 15 < δf < +5 kHz and 230 < δf < 280 kHz. In the red line during vertical pumping, a change from the artificial airglow generation to the ionospheric background suppression was detected when the F-layer cutoff frequency was decreased. During magnetic zenith pumping, a wide (about 30°) background suppression zone was observed around the airglow spot with an about 6° angular width

The 630 nm and 557.7 nm Airglow During HF Ionosphere Pumping by the SURA Facility Radiation for Pump Frequencies Near the Fourth Electron Gyroharmonic

© 2015, Springer Science+Business Media New York. We present the results of analysis of the dependence of the ionospheric airglow in the red (630 nm) and green (557.7 nm) lines of atomic oxygen on the pump-wave frequency f0 near the fourth electron gyroharmonic 4fce. The experimental data were obtained in 2012 using the SURA heating facility. Stimulated electromagnetic emission spectra were used to determine the relation between f0 and 4fce. It is found that at f0 > 4fce and δf = f0 − 4fce ≈ 15–20 kHz the red-line airglow intensity is about a factor of 1.5 higher for the magnetic zenith pumping (when the pump beam is inclined 12° south of the magnetic field direction) than for the vertical pumping. In the green line for the same offsets δf, the airglow was recorded with confidence only during magnetic zenith pumping. During vertical pumping, no regular dependence of the red-line airglow intensity on δf in the range −15 < δf < 280 kHz was obtained, while the green-line airglow was observed at 15 < δf < +5 kHz and 230 < δf < 280 kHz. In the red line during vertical pumping, a change from the artificial airglow generation to the ionospheric background suppression was detected when the F-layer cutoff frequency was decreased. During magnetic zenith pumping, a wide (about 30°) background suppression zone was observed around the airglow spot with an about 6° angular width

The 630 nm and 557.7 nm Airglow During HF Ionosphere Pumping by the SURA Facility Radiation for Pump Frequencies Near the Fourth Electron Gyroharmonic

© 2015, Springer Science+Business Media New York. We present the results of analysis of the dependence of the ionospheric airglow in the red (630 nm) and green (557.7 nm) lines of atomic oxygen on the pump-wave frequency f0 near the fourth electron gyroharmonic 4fce. The experimental data were obtained in 2012 using the SURA heating facility. Stimulated electromagnetic emission spectra were used to determine the relation between f0 and 4fce. It is found that at f0 > 4fce and δf = f0 − 4fce ≈ 15–20 kHz the red-line airglow intensity is about a factor of 1.5 higher for the magnetic zenith pumping (when the pump beam is inclined 12° south of the magnetic field direction) than for the vertical pumping. In the green line for the same offsets δf, the airglow was recorded with confidence only during magnetic zenith pumping. During vertical pumping, no regular dependence of the red-line airglow intensity on δf in the range −15 < δf < 280 kHz was obtained, while the green-line airglow was observed at 15 < δf < +5 kHz and 230 < δf < 280 kHz. In the red line during vertical pumping, a change from the artificial airglow generation to the ionospheric background suppression was detected when the F-layer cutoff frequency was decreased. During magnetic zenith pumping, a wide (about 30°) background suppression zone was observed around the airglow spot with an about 6° angular width

The 630 nm and 557.7 nm Airglow During HF Ionosphere Pumping by the SURA Facility Radiation for Pump Frequencies Near the Fourth Electron Gyroharmonic

© 2015, Springer Science+Business Media New York. We present the results of analysis of the dependence of the ionospheric airglow in the red (630 nm) and green (557.7 nm) lines of atomic oxygen on the pump-wave frequency f0 near the fourth electron gyroharmonic 4fce. The experimental data were obtained in 2012 using the SURA heating facility. Stimulated electromagnetic emission spectra were used to determine the relation between f0 and 4fce. It is found that at f0 > 4fce and δf = f0 − 4fce ≈ 15–20 kHz the red-line airglow intensity is about a factor of 1.5 higher for the magnetic zenith pumping (when the pump beam is inclined 12° south of the magnetic field direction) than for the vertical pumping. In the green line for the same offsets δf, the airglow was recorded with confidence only during magnetic zenith pumping. During vertical pumping, no regular dependence of the red-line airglow intensity on δf in the range −15 < δf < 280 kHz was obtained, while the green-line airglow was observed at 15 < δf < +5 kHz and 230 < δf < 280 kHz. In the red line during vertical pumping, a change from the artificial airglow generation to the ionospheric background suppression was detected when the F-layer cutoff frequency was decreased. During magnetic zenith pumping, a wide (about 30°) background suppression zone was observed around the airglow spot with an about 6° angular width