Enhancement of atmospherics associated with premonsoon thunderclouds
01 Oct 1965-Journal of Atmospheric and Solar-Terrestrial Physics (Pergamon)-Vol. 27, Iss: 10, pp 1105-1109
TL;DR: In this paper, the occurrence of premonsoon thunderclouds (Nor' westers) in the neighbourhood of Calcutta is frequently associated with an increase in the integrated field intensity of atmospherics received on a frequency of 30 kc/s.
Abstract: It is shown that the occurrence of premonsoon thunderclouds (Nor' westers) in the neighbourhood of Calcutta is frequently associated with an increase in the integrated field intensity of atmospherics received on a frequency of 30 kc/s.
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TL;DR: In this article, a quasi-period of 1-4 hours was observed for VLF fading in Calcutta (lat. 22°34′N; long. 88°24′E; geomagnetic lat. 11°54′N) on 30 kc/s.
Abstract: Reports have been made of long-period fading of VLF atmospherics observed on certain nights [Sachdev, 1958; Gherzi, 1961]. The fading has a quasi-period of 1–4 hours. The origin of the fading is not yet clearly understood. A recent observation of the fading in Calcutta (lat. 22°34′N; long. 88°24′E; geomagnetic lat. 11°54′N) on 30 kc/s revealed a connection of the phenomenon with geomagnetic activity.
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TL;DR: In this article, an electrical effect accompanying the orderly freezing of dilute aqueous solutions is reported, and the dependence of the effect on the structure of the ions of the solute and the molecular structure of water is shown.
Abstract: The discovery of an electrical effect accompanying the orderly freezing of dilute aqueous solutions is reported. Potential differences as great as 230 volts are measured across the water-ice interface during the the freezing process. At a freezing rate of about 1 cc per min., a current of 1 \ensuremath{\mu}amp. is measured. The character of the effect is a function of the nature and concentration of the solute. The dependence of the effect on the structure of the ions of the solute and the molecular structure of water is shown.Possible application of this effect to chemical detection and to the formation of thunderstorm electricity is discussed.
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TL;DR: The importance of bringing statistical considerations into the field of assessment of atmospheric noise interference is discussed and a procedure for the collection of data and its assessment for obtaining monthly values for a specific service, broadcasting, is described.
Abstract: The paper gives a general survey of the problem of atmospheric noise measurement and establishes, by a subjective method, a criterion for assessing the annoyance value of the noise to broadcast reception. There follows the development of an objective method of measurement and a comparison is made between these measurements and the subjective observations, etc. Ten impulses per minute are estimated to have an annoyance value to the listener of broadcast programmes. Noise is classified into three types: (a) type A noise giving the impression of continuous noise, (b) type B noise coming as distinct impulses, and (c) type C noise, a special form of type B noise arising from local thunderstorms. The importance of bringing statistical considerations into the field of assessment of atmospheric noise interference is discussed and a procedure for the collection of data and its assessment for obtaining monthly values for a specific service, broadcasting, is described.
26 citations
TL;DR: In this article, the authors studied the effect of severe thunderstorms of the squall type, known as "nor'westers", which are a special feature of the weather of this part of India (Bengal) in the pre-monsoon months March-May.
Abstract: IN the course of the ionospheric observations carried out at Calcutta (lat. 22° 33′ N., long. 88° 21′ E.) for more than two decades, it had always been found that sporadic E ionization (E
s) is greatly increased during the occurrence of thunderstorms. In view of the persistence of the phenomenon, it was thought worth while to make a close.study of the increase of E
s ionization during the occurrence of severe thunderstorms of the squall type, known as ‘nor’westers', which are a special feature of the weather of this part of India (Bengal) in the pre-monsoon months March–May. During these thunderstorms the wind generally blows from a north-westerly direction with velocity often exceeding 50 miles/hr. The thunderstorms are invariably accompanied by lightning discharges.
18 citations