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The 22 July 2009 Total Solar Eclipse: modeling D region Ionosphere using Narrowband VLF observations

Venkatesham, K. and Singh, R. and Maurya, A.K. and Dube, A. and Kumar, Sushil and Phanikumar, D.V. (2018) The 22 July 2009 Total Solar Eclipse: modeling D region Ionosphere using Narrowband VLF observations. Journal of Geophysical Research: Space Physics, NA . NA. ISSN 2156-2202

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    Abstract

    We present D region ionospheric response to 22 July 2009 total solar eclipse by modeling 19.8‐kHz signal from NWC very low frequency (VLF) navigational transmitter located in the Australia. NWC VLF signal was received at five stations located in and around eclipse totality path in the Indian, East Asian, and Pacific regions. NWC signal great circle paths to five stations are unique having eclipse coverage from no eclipse to partiality to totality regions, and the signal is exclusively confined in the low and equatorial regions. Eclipse‐induced modulations in NWC signal have been modeled by using long‐wave propagation capability code to obtain D region parameters of reflection height (H′) and sharpness factor (β). Long‐wave propagation capability modeling showed an increase in H′ of about 2.3 km near central line of totality, 3.0 km in the region near to totality fringe, and 2.4 to 3.0 km in the region under partial eclipse. Using H′ and β, Wait ionosphere electron density (Ne) profile at the daytime altitude of 75 km showed a decrease in Ne by about 58% at a station near totality central line, whereas at totality fringe and in partial eclipse region decrease in the Ne was between 63% and 71% with respect to normal time values. The eclipse associated variations in the H′, β, and Ne are less in low‐latitude region as compared to midlatitude. The study contributes to explain observations of wave‐like signature in the D region during an eclipse and difference in the eclipse effect in the different latitude‐longitude sectors.

    Item Type: Journal Article
    Subjects: Q Science > QC Physics
    Divisions: Faculty of Science, Technology and Environment (FSTE) > School of Engineering and Physics
    Depositing User: Ms Shalni Sanjana
    Date Deposited: 04 Feb 2019 11:02
    Last Modified: 26 Mar 2019 16:14
    URI: http://repository.usp.ac.fj/id/eprint/11289
    UNSPECIFIED

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