Commission 8: Progress in Radio Noise of Terrestrial Origin

Pierce, E. T.

doi:10.1029/rs004i007p00661

Cited by 5 publications

(3 citation statements)

References 45 publications

(24 reference statements)

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“…Estimates of z have been obtained in various parts of the world using visual observations, electric field change records, 931 and simple lightning flash counter records, either singly or in various combinations [Pierce, 1965[Pierce, , 1970Prentice and Mackerras, 1977]. However, these estimates tend to be of low accuracy and doubtful comparability [Mackerras, 1985], and this has affected the reliability of consequential estimates of the variation of z with latitude and thunderdays per year.…”

mentioning

confidence: 99%

The cloud flash‐to‐ground flash ratio and other lightning occurrence characteristics in Kathmandu thunderstorms

Baral¹,

Mackerras²

1992

J. Geophys. Res.

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Lightning and thunderstorm observations have been made in Kathmandu, Nepal (27.4°N, 85.2°E) over the 21‐month period March 1987 to November 1988 inclusive, using direct observations of thunder and lightning, and the registrations of a CGR3 lightning flash counter that provided records of the approximate numbers of cloud flashes, positive ground flashes, and negative ground flashes with an effective range of about 14 km. The observation period effectively covered two thunderstorm seasons as almost no lightning occurred during the winter months. During 1987 and 1988 the mean thunderdays per year was 42. The principal use of the CGR3 registrations was to estimate the long‐term ratio of cloud flashes to ground flashes, denoted z; it was found that z was 2.1 in 1987 and 3.0 in 1988, with a two‐season mean of 2.7. The uncertainty in ratio values is about 30%. The registrations also enabled lightning flash densities to be estimated with an uncertainty of about 40%. The two‐season mean ground flash, cloud flash, and total flash densities were 2.4, 6.6, and 9.0 km−2 yr−1, respectively. There were well‐marked seasonal variations in occurrence, with about 82% of all lightning occurring between mid‐February and the end of May. During this premonsoon period there were steady rises to maximum values in May of the thunderdays per month (to 10), the monthly total flash density (to 2.9 km−2 month−1), and the monthly value of z (to 3.6). The range of values of z calculated from the records for individual thunderstorm days was 0.17 to infinity, but very little lightning was associated with the extreme values. A distribution of values of the ratio with respect to cumulative lightning occurrence shows that 80% of all lightning was associated with values of z (calculated on a thunderstorm day basis) between 1.3 and 6.7. There is reasonably good agreement between the value of z for Kathmandu and values of z for other places at similar latitudes. However, major differences have been found for low latitudes between recently measured values of z and earlier predictions of the latitudinal variation of z.

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mentioning

confidence: 99%

The cloud flash‐to‐ground flash ratio and other lightning occurrence characteristics in Kathmandu thunderstorms

Baral¹,

Mackerras²

1992

J. Geophys. Res.

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“…It may be noted that in the tropics most of the discharges b 90%) occur in clouds (Pierce, 1962;Williams et al, 1992), and that such cloud¯ashes will be rather inecient in exciting ground waves. Therefore, masking of the ionospherically re¯ected wave at 30 kHz due to the ground wave will not be severe.…”

Section: Discussionmentioning

confidence: 99%

Long-period fading in atmospherics during severe meteorological activity and associated solar geophysical phenomena at low latitudes

et al. 1998

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Abstract. The records of VLF atmospherics over Calcutta and then over Kalyani (West Bengal) during the torrential rainfall, caused by violent monsoon and post-monsoon depressions, exhibit distinct long-period fadings both at day and night. Interesting results obtained from an analysis of round-the-clock atmospherics data and associated meteorological parameters are reported in this paper. A possible correlation between the severe meteorological activity with the solar geophysical phenomena was studied. The results are indicative of an interesting sequence of solarterrestrial events. A tentative conclusion is reached, suggesting an origin of the fading from atmospheric gravity waves generated in the centre of activity of the depressions concerned.

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“…In this section, we examine the effect on the source location procedure of low level thunderstonn activity distributed over a large equatorial area. According to Pierce (1969a), large scale thunderatoisi areas have a characteristic cliEension of about 1000 Km (A = 4.5 ) or an area of 10 km . Herman (19^8) has concluded that the world's major thunderstorm f\ ?…”

Section: Unifoibi Equatorial Distribution Of Low Level Thunderstorm Amentioning

confidence: 99%

Research on Extremely Low Frequency Propagation With Particular Emphasis on Schumann Resonance and Related Phenomena. Part Ii. Location of Sources

Toomey¹,

Polk²

1970

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Commission 8: Progress in Radio Noise of Terrestrial Origin

Cited by 5 publications

References 45 publications

The cloud flash‐to‐ground flash ratio and other lightning occurrence characteristics in Kathmandu thunderstorms

The cloud flash‐to‐ground flash ratio and other lightning occurrence characteristics in Kathmandu thunderstorms

Long-period fading in atmospherics during severe meteorological activity and associated solar geophysical phenomena at low latitudes

Research on Extremely Low Frequency Propagation With Particular Emphasis on Schumann Resonance and Related Phenomena. Part Ii. Location of Sources

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