The total solar eclipse of 23 October 1976 observed at VLF

Lynn, K. J. W.

doi:10.1016/0021-9169(81)90156-2

Cited by 39 publications

(31 citation statements)

References 9 publications

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“…The ionospheric height of reflection was usually 3-8 km. Many researchers (Reeve and Rycroft, 1972;Sen Gupta et al, 1980;Lynn, 1981;Mendes Da Costa et al, 1995) concluded that the effects caused by a solar eclipse largely depend on the signal frequency and path length. Therefore, the researchers continued studying the ionospheric parameters during solar eclipses.…”

Section: Introductionmentioning

confidence: 99%

Effect of the total solar eclipse of March 20, 2015, on VLF/LF propagation

et al. 2016

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Abstract-The analyzed amplitude and phase variations in electromagnetic VLF and LF signals at 20-45 kHz, received in Moscow, Graz (Austria), and Sheffield (UK) during the total solar eclipse of March 20, 2015, are considered. The 22 analyzed paths have lengths of 200-6100 km, are differently oriented, and cross 40-100% occultation regions. Fifteen paths crossed the region where the occultation varied from 40 to 90%. Solar eclipse effects were found only on one of these paths in the signal phase (-50°). Four long paths crossed the 90-100% occultation region, and signal amplitude and phase anomalies were detected for all four paths. Negative phase anomalies varied from -75° to -90°, and the amplitude anomalies were both positive and negative and were not larger than 5 dB. It was shown that the effective height of the ionosphere varied from 6.5 to 11 km during the eclipse.

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Section: Introductionmentioning

confidence: 99%

Effect of the total solar eclipse of March 20, 2015, on VLF/LF propagation

et al. 2016

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“…On both sides of the eclipse track, daylight is present. Due to discontinuity at the boundary of the eclipse track, modal conversion (Lynn 1973(Lynn , 1981 can occur at VLF. Some energy may be transferred from the first mode to the other modes making the first mode suddenly weaker compared to the initial value.…”

Section: Discussionmentioning

confidence: 99%

“…The eclipse produced a phase delay of 6.4 μs and an amplitude change of 1.3 dB. So to say, various authors (Crary and Schneible 1965;Reeve and Rycroft 1972;Sen Gupta et al 1980;Lynn 1981;Mendes Da Costa et al 1995) reported the solar eclipse effects were to be path and frequency dependent. Experimental measurements of the ionospheric parameters at the time of solar eclipses are needed to understand the behaviour and characteristics of the ionosphere (Buckmaster and Hansen 1986;Zeng et al 1997;Clilverd et al 2001;Sanders 2001;Founda et al 2007).…”

Section: Introductionmentioning

confidence: 99%

“…They attributed the result as a consequence of decrease in ionization in the D-region and increase in the reflection height. Lynn (1981) reported results of VLF transmissions at 13.6 and 22.3 kHz from Omega Reunion, Omega, Japan and NWC, received at Melbourne during the total solar eclipse of 23 October 1976. The phase response was found to be a non-linear function of solar obscuration with a maximum phase deviation which was less than expected when compared with the normal diurnal phase variation.…”

Section: Introductionmentioning

confidence: 99%

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Effects of a Solar Eclipse on the Propagation of VLF-LF Signals: Observations and Results

De¹,

De²,

Bandyopadhyay³

et al. 2011

Terr. Atmos. Ocean. Sci.

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The results from the measurements of some of the fundamental parameters (amplitude of sferics and transmitted signal, conductivity of lower ionosphere) of the ionospheric responses to the 22 July 2009 solar eclipse (partial: 91.7%) are shown. This study summarizes our results from sferics signals at 81 kHz and subionospheric transmitted signals at 19.8 and 40 kHz recorded at Agartala, Tripura (latitude: 23°N, longitude: 91.4°E). We observed significant absorption in amplitude of these signals during the eclipse period compared to their ambient values for the same period during the adjacent 7 days. The signal strength along their propagation paths was controlled by the eclipse associated decrease in ionization in the D-region of the ionosphere. Waveguide mode theory calculations show that the elevation of the height of lower ionosphere boundary of the Earth-ionosphere waveguide to a value where the conductivity parameter was 10 6 unit. The absorption in 81 kHz sferics amplitude is high compared to the absorption in the amplitude of 40 kHz signal transmitted from Japan. The simultaneous changes in the amplitudes of sferics and in the amplitude of transmitted signals assert some sort of coupling between the upper atmosphere and the Earth's near-surface atmosphere prevailing clouds during solar eclipse.

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“…There are several papers that report changes in the Earth's near-surface vertical electric potential gradient during solar eclipses (KAMRA and VARSHNEYA, 1967;DOLEZALEK, 1972;KAMRA et al, 1982;DHANORKAR et al, 1989), while others report the disturbances in the ionosphere during solar eclipses in terms of changes in the phase of VLF transmissions (KAUFMANN and SCHAAL, 1968;HOY, 1969;RICARDO et al, 1970;PANT and MAHRA, 1980;PANT and MAHRA, 1994;LELE et al, 1997;CLILVERD et al, 2001). These changes are considered to be path-and frequencydependent (CRARY and SCHNEIBLE, 1965;KAUFMANN and SCHAAL, 1968;REEVE and RYCROFT, 1972;MAHRA, 1976;PANT and MAHRA, 1980;SENGUPTA et al, 1980;LYNN, 1981;MENDES da COSTA et al, 1995). The spectral behaviour of the effects for constant path has yet to be explored.…”

Section: Introductionmentioning

confidence: 99%

The Effects of Solar Eclipse of August 1, 2008 on Earth’s Atmospheric Parameters

De²,

Bandyopadhyay³

et al. 2009

Pure Appl. Geophys.

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Several experiments were undertaken at Kolkata (latitude: 22°34 0 N, longitude: 88°30 0 E) on the solar eclipse day of August 1, 2008 to observe the effects of the solar eclipse on Fair Weather Field (FWF) and VLF amplitude and phase. The experimental results presented here show significant deviations of the observed parameters from their normal values, as they are determined by the average of the records obtained on 5 days adjacent to the day of the solar eclipse.

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The total solar eclipse of 23 October 1976 observed at VLF

Cited by 39 publications

References 9 publications

Effect of the total solar eclipse of March 20, 2015, on VLF/LF propagation

Effect of the total solar eclipse of March 20, 2015, on VLF/LF propagation

Effects of a Solar Eclipse on the Propagation of VLF-LF Signals: Observations and Results

The Effects of Solar Eclipse of August 1, 2008 on Earth’s Atmospheric Parameters

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