التفاصيل البيبلوغرافية
| العنوان: |
Effects of a Solar Eclipse on the Propagation of VLF-LF Signals: Observations and Results. |
| المؤلفون: |
Kumar De, Barin1, Sundar De, Syam2 de_syam_sundar@yahoo.co.in, Bandyopadhyay, Bijoy2, Pal, Pinaki3, Ali, Rousan1,4, Paul, Suman2, Goswami, Prabir Kanta2 |
| المصدر: |
Terrestrial, Atmospheric & Oceanic Sciences. Aug2011, Vol. 22 Issue 4, p435-442. 8p. |
| مصطلحات موضوعية: |
*VLF radio wave propagation, *SOLAR eclipses, *IONOSPHERE, *ATMOSPHERICS, *ABSORPTION, *ATMOSPHERIC ionization, *EARTH (Planet) |
| مصطلحات جغرافية: |
TRIPURA (India), INDIA, JAPAN |
| مستخلص: |
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 1010 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. [ABSTRACT FROM AUTHOR] |
| قاعدة البيانات: |
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