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Journal ArticleDOI

On some characteristics of tropical atmospherics due to monsoon clouds. Über Charakteristiken tropischer Atmospherics aus Monsunwolken

01 Dec 1982-Vol. 31, Iss: 4, pp 411-419
TL;DR: The field intensity of VLF-atmospherics recorded over the tropical station, Calcutta (22°34′N, 88°24′E) occasionally exhibit a characteristic fall in association with the ground rainfall during monsoon months.
Abstract: The field intensity of VLF-atmospherics recorded over the tropical station, Calcutta (22°34′N, 88°24′E) occasionally exhibit a characteristic fall in association with the ground rainfall during monsoon months. The sudden fall is followed by a pause and a subsequent recorvery thus forming a clipped saw-tooth like appearance. The occurrences and magnitudes of the fall are predominant at 20 kHz in the VLF-band. They mostly occur around local noon and midnight hours.
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DOI
01 Jan 2022-Mausam
TL;DR: In this paper , the authors discuss the importance of the role of the human body in health care and propose a method to improve the health care system of the individual body using the body's own information.
Abstract: bl 'kks/k i= esa vizSy 2009 ls vDrwcj 2009 dh vof/k ds nkSjku HkkSfrdh foHkkx] f=iqjk fo’ofo|ky; }kjk oh- ,y- ,Q- ok;qeaMyh; vFkok LQsfjDl dh vfHkyk{kf.kd fofo/krk dks pkj vyx & vyx vko`fr;ksa esa ntZ fd;k x;k gSA bl 'kks/k i= esa mRrj iwoZ Hkkjr ds 76 lfØ; xtZ ds lkFk rwQku okys vf/kdk¡’k fnuksa ds vk¡dMs+ iz;qDr fd, x,A buls izkIr ifj.kkeksa esa ekulwu ds nkSjku LQsfjDl ifjorZu esa dbZ izdkj dh fo’ks"krk,¡ n’kkZbZ xbZ gSaA bu Øfed fxjkoV] Øfed o`f) ¼th- ,Q- th- vkj-½] Øfed o`f) vpkud fxjkoV ¼th- vkj- ,l- ,Q-½] Øfed o`f) Øfed fxjkoV ¼th- vkj th- ,Q-½] Øfed fxjkoV vpkud o`f) ¼th- ,Q-,l- vkj-½] vkdfLed o`f) Øfed fxjkoV ¼,l- vkj- th- ,Q-½] vpkud fxjkoV vpkud o`f) ¼,l- vkj- ,l- ,Q-½ vpkud fxjkoV vpkud o`f) ¼,l- ,Q- ,l- vkj-½ vpkud fxjkoV Øfed o`f) ¼,l- ,Q- th- vkj-½ rFkk dBksj ¼Spiky½ Lo:i esa n’kkZ;k x;k gSA ekulwuh lfØ; xtZ ds lkFk rwQkuksa okys vf/kdka’k fnuksa esa lHkh izdkj ds iSVuksaZ esa ¼th- vkj th- ,Q-½ dh vko`fr vf/kdrj izdj.kksa esa ntZ gqbZ gS ¼izR;sd vko`fr esa vkSlru yxHkx 37 izfr’kr ?kVuk,¡ ntZ gqbZ gSa½ gekjh izs{k.kkRed vof/k ds nkSjku 23&26 ebZ dh vof/k esa caxky dh [kkM+h esa ‘vkbZyk’ uked ,d rhoz m".kdfVca/kh; pØokr vkj-,l-,e-lh- inuke% ch- vks- ch- vks-2] ts- Vh- MCY;w- lh- inuke% vks- Vw- ch- vk;k FkkA 25 ebZ 2009 ds m".k ds m".kdfVca/kh; pØokr ds nkSjku lHkh izdkj ds lkekU; ekulwuh vof/k dh vfHkyk{kf.kd fo’ks"krkvksa esa ,l-vkj-,l-,Q- ¼izR;sd vko`fr esa 86 izfr’kr ds vkSlru nj ls ?kfVr½ vko`fr vf/kdrj izdj.kksa esa ns[kh xbZ gSA tc pØokr caxky dh [kkM+h ds rVksa ls Vdjk;k ml fnu ds LQsfjDl ds vyx&vyx vko`fr forj.kksa ds vuqlkj o`f) vkSj fxjkoV dk xaHkhjrk ls fo’ys"k.k fd;k x;kA ekulwuh fnuksa vkSj ‘vkbyk’ pØokr lfØ; fnol ds lHkh ds lHkh izdkj ds iSVuksaZ dk rqyukRed v/;;u fd;k x;kA gekjs fu"d"kZ ds vuqlkj izpaM pØokr ‘vkbyk’ vkSj vU; xtZ Hkjs rwQku okys ekulwuh fnuksa ds nkSjku mRrj iwoZ Hkkjr esa cknyksa dh lw{e lajpuk esa dkQh varj fn[kkA pØokrh xfrfof/k ds nkSjku LQSfjDl ds ns[ks x, cnyko dh laHkkfor O;k[;k dks xtZ Hkjs rwQku okys cknyksa dh rfM+r xfrfof/k ds vk/kkj ij le>k;k x;k gSA The present work reports the characteristic variations in VLF atmospherics or sferics at four discrete frequencies recorded at the Department of Physics, Tripura University, during the period from April 2009 to October 2009. Data from 76 active thunder days over North-East India is considered for the present investigation. Results show several types of features in the variation of sferics during the monsoon period. These are termed as gradual fall gradual rise (GFGR), gradual rise sudden fall (GRSF), gradual rise gradual fall (GRGF), gradual fall sudden rise (GFSR), sudden rise gradual fall (SRGF), sudden rise sudden fall (SRSF), sudden fall sudden rise (SFSR), sudden fall gradual rise (SFGR) and spiky. During the Monsoon thunder active days, amongst all the patterns, GRGF occurred in most of the cases in all frequencies (average occurrence rate around 37% in each frequency). During our observational period, a severe tropical cyclonic storm named “AILA” (RSMC Designation BOB02, JTWC Designation 02B) occurred over the Bay of Bengal during 23-26 May 2009. Among several characteristic features during normal Monsoon period, SRSF (average occurrence rate around 86 % in each frequency) dominated the sferics on the 25 May, 2009, when the cyclone struck the coastal areas of the Bay of Bengal. The sferics of that day has been analyzed critically with respect to discrete frequency distribution of rise rate and fall rate of the intensity of the sferics. A comparison is made for all the patterns for the Monsoon days and the AILA cyclone active day. Our findings show substantial difference in the microstructure of clouds producing severe cyclonic storms like AILA and other thunderstorms during Monsoon seasons over North-East India. The possible interpretation of the observed variations in sferics is explained on the basis of the electrical activity that occurs inside a thunder-cloud especially during cyclonic activity.

1 citations

Journal Article
01 Jan 2013-Mausam
TL;DR: In this article, the authors reported the characteristic variations in VLF atmospherics or sferics at four discrete frequencies recorded at the Department of Physics, Tripura University, during the period from April 2009 to October 2009.
Abstract: The present work reports the characteristic variations in VLF atmospherics or sferics at four discrete frequencies recorded at the Department of Physics, Tripura University, during the period from April 2009 to October 2009. Data from 76 active thunder days over North-East India is considered for the present investigation. Results show several types of features in the variation of sferics during the monsoon period. These are termed as gradual fall gradual rise (GFGR), gradual rise sudden fall (GRSF), gradual rise gradual fall (GRGF), gradual fall sudden rise (GFSR), sudden rise gradual fall (SRGF), sudden rise sudden fall (SRSF), sudden fall sudden rise (SFSR), sudden fall gradual rise (SFGR) and spiky. During the Monsoon thunder active days, amongst all the patterns, GRGF occurred in most of the cases in all frequencies (average occurrence rate around 37% in each frequency). During our observational period, a severe tropical cyclonic storm named "AILA" (RSMC Designation BOB02, JTWC Designation 02B) occurred over the Bay of Bengal during 23-26 May 2009. Among several characteristic features during normal Monsoon period, SRSF (average occurrence rate around 86 % in each frequency) dominated the sferics on the 25 May, 2009, when the cyclone struck the coastal areas of the Bay of Bengal. The sferics of that day has been analyzed critically with respect to discrete frequency distribution of rise rate and fall rate of the intensity of the sferics. A comparison is made for all the patterns for the Monsoon days and the AILA cyclone active day. Our findings show substantial difference in the microstructure of clouds producing severe cyclonic storms like AILA and other thunderstorms during Monsoon seasons over North-East India. The possible interpretation of the observed variations in sferics is explained on the basis of the electrical activity that occurs inside a thunder-cloud especially during cyclonic activity.

1 citations


Cites background from "On some characteristics of tropical..."

  • ...…intensity of atmospherics (IFIA) at different frequencies characterized the dynamic electrical behavior of the thunderstorm activity and also confirmed that the GRGF event mainly occurred in the monsoonal thundercloud activity (Sarkar et al., 1982, Bhattacharya et al., 1994, Guha et al., 2009)....

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Journal ArticleDOI
TL;DR: In this paper, a description of the techniques and instruments developed for the study of atmospheric noise is given, along with a detailed discussion of the methods and instruments used for this purpose.
Abstract: A description of the techniques and instruments developed for the study of atmospheric noise is given.
References
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Journal ArticleDOI
TL;DR: In this paper, the authors survey recent work on the electricity of cloud droplets, drizzle, and raindrops and describe the instruments used in such observations, and sketch ongoing attempts to observe the charge distribution of the particles in relation to the cloud life cycle.
Abstract: The purpose of this review is to survey recent work on the electricity of cloud droplets, drizzle, and raindrops and, in particular, to describe the instruments used in such observations. The review begins with a number of basic definitions and key questions in this area of cloud physics. A detailed description of instruments for the measurement of drop size and charge, both at the ground and in clouds, follows. The third section presents and interprets some of the data gathered with these instruments. We then sketch ongoing attempts to observe the charge distribution of the particles in relation to the cloud life cycle and to determine the size range of the particles that constitute the main charge carrier in the cloud. We conclude with a statement of three current goals of investigation.

59 citations

Journal Article
01 Jan 1975-Mausam
TL;DR: In this article, the differences in the thermodynamic structure of the atmosphere over India and the adjoining areas between active and weak monsoon (southwest) periods in various meteorological sub-divisions are presented.
Abstract: The differences in the thermodynamic structure of the atmosphere over India and the adjoining areas between active and weak monsoon (southwest) periods in the various meteorological sub-divisions are presented. The mean dry bulb and dew point remperatures and equivalent potentioal temperatures during active and weak monsoon were calculated at all the radiosonde stations in India and neighbourhood and studied. The results show that whatever be the monsoon activity, there is no significant change in the dry bulb temperature at any level and the moisture content in the lower tropospheric levels remains high without any appreciable variation. The main change is in the moisture content in the mid-tropospherica levels. The implication of these results in the vertical circulation associated with active and weak monsoon and in the radiation budget are brought out, since the vigorous ascending air in the areas of strong monsoon ultimately subsides slowly over the regions of weak monsoon. The region of the seasonal monsoon trough has been indentified as the area of maximum total energy both in active and weak monsoon is least. This is also the area where convective instability is present upto greater heights than elsewhere. The estimated heights of cb tops are highest in the region of the seasonal monsoon trough. It is also shown that there is no reversal of virtual temperature gradient over the northwest India in the midtropospheric levels during the SW monsoon season.

12 citations

Journal ArticleDOI
01 Mar 1980
TL;DR: In this article, the integrated field intensity of atmospherics (IFIA) observed at 10 and 20 kHz have been critically examined in relation to monsoon, premonsoon and postmonsoon thunderstorms.
Abstract: Thunderstorm associated atmospherics during the monsoon, premonsoon and postmonsoon seasons over the tropical station Calcutta show some typical characteristics. In all the cases gradual rise of atmospherics (GRA) and steady recovery of atmospherics (SRA) have been found. In between the above two changes, there is the sudden enhancement of atmospherics (SEA) which is some times composed of two components SEA1 and SEA2. All the above facts of the integrated field intensity of atmospherics (IFIA) observed at 10 and 20 kHz have been critically examined here in relation to monsoon, premonsoon and postmonsoon thunderstorms. The results exhibit that the precipitation is associated with the steady recovery of IFIA during the monsoon and postmonsoon thunderstorms while that during premonsoon thunderstorms is associated with the second sudden enhancement. These anomalies have been interpreted in terms of charge separation within thunderclouds. Moreover, the difference of the respective amplitudes at 10 and 20 kHz of the different variations of IFIA have also been critically focussed.

10 citations


"On some characteristics of tropical..." refers background in this paper

  • ...as experienced over the tropical coast Calcutta (2~ 34 ,88 ..4 E), in the eastern India, has been reported earlier [7, 8 ] while the investigations of the effect of monsoon clouds on it are yet lacking [3, 5, 6]. The geographical...

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Journal ArticleDOI
01 Jan 1965-Weather

7 citations