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      Permanent link:
      https://www.ias.ac.in/article/fulltext/jess/122/04/1013-1021

    • Keywords

       

      Lightning; VLF sferics; thunderstorm; integrated field intensity of sferics.

    • Abstract

       

      Electromagnetic waves from lightning activity, commonly known as atmospherics or sferics serve as an effective tool for studying the lower ionosphere as well as thunderstorm activity. It is also useful for locating lightning strokes regionally and globally. In this paper, we present the analysis of the Integrated Field Intensity of Sferics (IFIS) at six discrete VLF frequencies for 30 lightning-associated overhead thunderstorms in Tripura, within the period from August 2009 to October 2010. An ingeniously developed well calibrated GPS locked software VLF receiver, located at the Department of Physics, Tripura University (23.5°N, 91.25°E), is used for the present study. Two distinct types of variations of IFIS, (i) single peak and (ii) dual peak are found characterizing each thunderstorm and their occurrence show nearly inverse character. The spectral character of IFIS rise rate, fall rate and rate of enhancement for each type is studied searching for suitable frequencies in the VLF range to forecast a thunderstorm. It is concluded that VLF sferics from 3–10 kHz are the most effective in terms nowcasting an incoming thunderstorm well before 3–4 hours of its peak occurrence, when there may not be any visual indication of the thunderstorm.

    • Author Affiliations

       

      A Guha1 Trisanu Banik1 Barin Kumar De1 Rakesh Roy1 Abhijit Choudhury1

      1. Department of Physics, Tripura University, Suryamaninagar 799 022, Tripura, India.
    • Dates

       
  • Journal of Earth System Science | News

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