. The temporal and spatial distributions of cloud-to-ground (CG) lightning in and around Japan were examined for a seven-year period (2002–2008) by using lightning location data from the Lightning Detection Network System operated by the Japan Meteorological Agency. The frequency of CG flashes was found to be high over land area in summer. During winter, many CG flashes were located along the coast of the Sea of Japan of central Honshu (Hokuriku area) and off the coast of the Pacific side (Kanto-Tokai area). A detailed analysis of the Hokuriku and Kanto-Tokai areas revealed diurnal variations characterized by a peak in the afternoon for inland areas, and a peak in early morning for coastal and offshore areas of the Hokuriku area in summer. For winter, the diurnal variation of CG flash density is indistinct in the Hokuriku region, where CG flashes are strongly concentrated within 20 km from the coastline, whereas it has a maximum in the early morning off the coast of the Kanto-Tokai area.
{"title":"Statistical Analysis of Temporal and Spatial Distributions of Cloud-to-Ground Lightning in Japan from 2002 to 2008","authors":"Kyosuke Ishii, S. Hayashi, F. Fujibe","doi":"10.1541/JAE.34.79","DOIUrl":"https://doi.org/10.1541/JAE.34.79","url":null,"abstract":". The temporal and spatial distributions of cloud-to-ground (CG) lightning in and around Japan were examined for a seven-year period (2002–2008) by using lightning location data from the Lightning Detection Network System operated by the Japan Meteorological Agency. The frequency of CG flashes was found to be high over land area in summer. During winter, many CG flashes were located along the coast of the Sea of Japan of central Honshu (Hokuriku area) and off the coast of the Pacific side (Kanto-Tokai area). A detailed analysis of the Hokuriku and Kanto-Tokai areas revealed diurnal variations characterized by a peak in the afternoon for inland areas, and a peak in early morning for coastal and offshore areas of the Hokuriku area in summer. For winter, the diurnal variation of CG flash density is indistinct in the Hokuriku region, where CG flashes are strongly concentrated within 20 km from the coastline, whereas it has a maximum in the early morning off the coast of the Kanto-Tokai area.","PeriodicalId":274637,"journal":{"name":"Journal of atmospheric electricity","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126012082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Akita, Z. Kawasaki, S. Yoshida, T. Morimoto, T. Ushio
. We propose a new method of estimation for the amount of charge removed by individual lightning flashes in thunderclouds by means of three-dimensional (3D) VHF images and the associated electric field (E-field) change on the ground. In this method, we assume a reasonable assumption that the VHF sources located by the VHF broadband digital interferometers (VHF DITFs) correspond to charge transfer of each breakdown. We examine 3D VHF images recorded in Darwin, Australia and estimate the amount of charge removed by lightning discharges in thunderclouds. The average amount of charge removed in a CG and an IC flash is 28 C and 33 C, respectively. These results are in reasonable agreement with previous estimations for the amount of charge transferred using E-field measurements. The charge density removed by an IC flash was also estimated to be 4.3 × 10 -10 C/m 3 for the positive charge region and 5.8 × 10 -9 C/m 3 for the negative charge region, respectively. The estimation results indicate the charge structure before the flash occurred in thunderclouds.
{"title":"Estimation for charge distributions related with individual lightning discharges using VHF broadband digital interferometer","authors":"M. Akita, Z. Kawasaki, S. Yoshida, T. Morimoto, T. Ushio","doi":"10.1541/JAE.32.55","DOIUrl":"https://doi.org/10.1541/JAE.32.55","url":null,"abstract":". We propose a new method of estimation for the amount of charge removed by individual lightning flashes in thunderclouds by means of three-dimensional (3D) VHF images and the associated electric field (E-field) change on the ground. In this method, we assume a reasonable assumption that the VHF sources located by the VHF broadband digital interferometers (VHF DITFs) correspond to charge transfer of each breakdown. We examine 3D VHF images recorded in Darwin, Australia and estimate the amount of charge removed by lightning discharges in thunderclouds. The average amount of charge removed in a CG and an IC flash is 28 C and 33 C, respectively. These results are in reasonable agreement with previous estimations for the amount of charge transferred using E-field measurements. The charge density removed by an IC flash was also estimated to be 4.3 × 10 -10 C/m 3 for the positive charge region and 5.8 × 10 -9 C/m 3 for the negative charge region, respectively. The estimation results indicate the charge structure before the flash occurred in thunderclouds.","PeriodicalId":274637,"journal":{"name":"Journal of atmospheric electricity","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128106169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The impact is evaluated of nearby trees and bushes on the effective height of a vertical electric antenna in the extremely low frequency (ELF) band. We try to find the distance at which the plants might influence the local quasi-static field and thus disturb the effective height of antenna. The obtained results might be helpful when choosing the place of antenna positioning in the long-term ELF monitoring.
{"title":"Impact of Trees and Bushes on the Effective Height of a Vertical Electric ELF Antenna","authors":"E. Yatsevich, A. Nickolaenko","doi":"10.1541/JAE.32.65","DOIUrl":"https://doi.org/10.1541/JAE.32.65","url":null,"abstract":"The impact is evaluated of nearby trees and bushes on the effective height of a vertical electric antenna in the extremely low frequency (ELF) band. We try to find the distance at which the plants might influence the local quasi-static field and thus disturb the effective height of antenna. The obtained results might be helpful when choosing the place of antenna positioning in the long-term ELF monitoring.","PeriodicalId":274637,"journal":{"name":"Journal of atmospheric electricity","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131661028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Hobara, T. Harada, K. Ohta, M. Sekiguchi, M. Hayakawa
In this paper we use a long-term record of the Schumann resonance (SR) intensity observed in Nakatsugawa, Japan and global lightning activity to study the global temperature change. The cumulative magnetic field energy from the first and second modes of SR intensity for 4 years is derived for two horizontal components. The monthly dependence of field energy is compared with the global lightning and temperature data for the corresponding time period. As a result SR energy is found to be correlated well with the temperature in the middle latitude and global lightning activity. Furthermore the principal component analysis (PCA) is applied to extract the periodical component in each data set. The annual component of SR energy has a significant correlation with the middle latitude temperature, whilst the semi-annual component of the SR energy has a significant correlation with low latitude temperature. The correlation pattern varies with magnetic components and the contribution from African and Asian thunderstorm activity to the global SR is studied.
{"title":"A study on global temperature and thunderstorm activity by using the data of Schumann resonance observed at Nakatsugawa, Japan","authors":"Y. Hobara, T. Harada, K. Ohta, M. Sekiguchi, M. Hayakawa","doi":"10.1541/JAE.31","DOIUrl":"https://doi.org/10.1541/JAE.31","url":null,"abstract":"In this paper we use a long-term record of the Schumann resonance (SR) intensity observed in Nakatsugawa, Japan and global lightning activity to study the global temperature change. The cumulative magnetic field energy from the first and second modes of SR intensity for 4 years is derived for two horizontal components. The monthly dependence of field energy is compared with the global lightning and temperature data for the corresponding time period. As a result SR energy is found to be correlated well with the temperature in the middle latitude and global lightning activity. Furthermore the principal component analysis (PCA) is applied to extract the periodical component in each data set. The annual component of SR energy has a significant correlation with the middle latitude temperature, whilst the semi-annual component of the SR energy has a significant correlation with low latitude temperature. The correlation pattern varies with magnetic components and the contribution from African and Asian thunderstorm activity to the global SR is studied.","PeriodicalId":274637,"journal":{"name":"Journal of atmospheric electricity","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114853318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Hayakawa, Y. Kasahara, T. Nakamura, Y. Hobara, A. Rozhnoi, M. Solovieva, O. Molchanov, V. Korepanov
: The appearance of ionospheric perturbations in possible association with earthquakes (EQs) seems to be confirmed on the basis of both event and statistical studies, but the generation mechanism of those seismo-ionospheric perturbations is not well understood, though a few possible hypotheses have been proposed. Two hypotheses are promising candidates; one is so-called “chemical channel”, in which radon emanation results in the change in atmospheric conductivity, then in the atmospheric electric field, leading to the redistribution of ionospheric plasma, and the other is the excitation of atmospheric oscillations due to some precursory changes of ground surface, which propagate upward and induce the ionospheric perturbation. We support the second “atmospheric oscillation channel”, so that in this paper we present several evidences (or facts) in support of this hypothesis. First, we present some case studies of the enhancement of AGW (atmospheric gravity wave) modulation in subionospheric VLF/LF propagation data, and then a recent statistical treatment of this AGW modulation in VLF/LF data is reported. Further studies on the satellite observation and also on the satellite-ground coordinated measurements are presented in order to indicate the AGW as the agent of lithosphere-ionosphere coupling. Finally, our equipment recently developed to measure the Doppler-shift of a short-distance subionospheric LF signal is used to indicate the direct evidence of the AGW hypothesis. observational evidences of AGW fluctuations in subionospheric VLF/LF data, a statistical study of this AGW modulation in VLF/LF data, a case study and a statistical study on the mechanism on the basis of ground and satellite correlations, a new VLF/LF Doppler-shift observation, etc.
{"title":"Atmospheric gravity waves as a possible candidate for seismo-ionospheric perturbations","authors":"M. Hayakawa, Y. Kasahara, T. Nakamura, Y. Hobara, A. Rozhnoi, M. Solovieva, O. Molchanov, V. Korepanov","doi":"10.1541/JAE.31.129","DOIUrl":"https://doi.org/10.1541/JAE.31.129","url":null,"abstract":": The appearance of ionospheric perturbations in possible association with earthquakes (EQs) seems to be confirmed on the basis of both event and statistical studies, but the generation mechanism of those seismo-ionospheric perturbations is not well understood, though a few possible hypotheses have been proposed. Two hypotheses are promising candidates; one is so-called “chemical channel”, in which radon emanation results in the change in atmospheric conductivity, then in the atmospheric electric field, leading to the redistribution of ionospheric plasma, and the other is the excitation of atmospheric oscillations due to some precursory changes of ground surface, which propagate upward and induce the ionospheric perturbation. We support the second “atmospheric oscillation channel”, so that in this paper we present several evidences (or facts) in support of this hypothesis. First, we present some case studies of the enhancement of AGW (atmospheric gravity wave) modulation in subionospheric VLF/LF propagation data, and then a recent statistical treatment of this AGW modulation in VLF/LF data is reported. Further studies on the satellite observation and also on the satellite-ground coordinated measurements are presented in order to indicate the AGW as the agent of lithosphere-ionosphere coupling. Finally, our equipment recently developed to measure the Doppler-shift of a short-distance subionospheric LF signal is used to indicate the direct evidence of the AGW hypothesis. observational evidences of AGW fluctuations in subionospheric VLF/LF data, a statistical study of this AGW modulation in VLF/LF data, a case study and a statistical study on the mechanism on the basis of ground and satellite correlations, a new VLF/LF Doppler-shift observation, etc.","PeriodicalId":274637,"journal":{"name":"Journal of atmospheric electricity","volume":"280 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115763499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Changes are modeled of parameters of the global electric circuit caused by the giant gamma ray burst arrived at the Earth’s dayside on December 27 2004. Modification of the air conductivity by gamma rays alters the leakage current of the Earth–ionosphere cavity and causes a discrete radio pulse. Electric parameters of the air at the tropopause–troposphere altitudes play the key role. ELF spectrum of the “parametric” current moment is ‘red’ or ‘white’ depending on the particular model. Sample spectra and waveforms are presented of the parametric Q–burst.
{"title":"Source models for “parametric” Q-burst","authors":"A. Nickolaenko","doi":"10.1541/JAE.31.95","DOIUrl":"https://doi.org/10.1541/JAE.31.95","url":null,"abstract":"Changes are modeled of parameters of the global electric circuit caused by the giant gamma ray burst arrived at the Earth’s dayside on December 27 2004. Modification of the air conductivity by gamma rays alters the leakage current of the Earth–ionosphere cavity and causes a discrete radio pulse. Electric parameters of the air at the tropopause–troposphere altitudes play the key role. ELF spectrum of the “parametric” current moment is ‘red’ or ‘white’ depending on the particular model. Sample spectra and waveforms are presented of the parametric Q–burst.","PeriodicalId":274637,"journal":{"name":"Journal of atmospheric electricity","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116266825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Yamamoto, T. Mega, N. Ikeno, T. Shimomai, H. Hashiguchi, M. Yamamoto, M. Nakazato, Takuya Tajiri, Y. Ohigashi
{"title":"Assessment of radar reflectivity and Doppler velocity measured by Ka-band FMCW Doppler weather radar","authors":"M. Yamamoto, T. Mega, N. Ikeno, T. Shimomai, H. Hashiguchi, M. Yamamoto, M. Nakazato, Takuya Tajiri, Y. Ohigashi","doi":"10.1541/JAE.31.85","DOIUrl":"https://doi.org/10.1541/JAE.31.85","url":null,"abstract":"","PeriodicalId":274637,"journal":{"name":"Journal of atmospheric electricity","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115403523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
. Many observations have been conducted to clarify the relation between electromagnetic phenomena and seismic activities. We have been observing seismic electromagnetic waves in FM broadcasting frequency band from 76 MHz to 90 MHz using PLL type synthesized digital FM tuners since 1998. We are operating thirteen observatories in Japan. From observations at Ibaraki by the dual frequency method using two different frequencies, nine events of co-seismic electromagnetic waves were observed for seven years from January 1, 2002 to December 31, 2008. Received electromagnetic levels rose up at the same moment of arrival of seismic waves. Further, we examined the relation between the co-seismic broadband electromagnetic waves and the seismic parameters. It was confirmed that the detected peak electromagnetic levels were well correlated with the peak ground accelerations of the earthquakes.
{"title":"Observations of co-seismic broadband electromagnetic waves in the VHF band","authors":"K. Shin, M. Nishi, Teruaki Yoshida","doi":"10.1541/JAE.31.121","DOIUrl":"https://doi.org/10.1541/JAE.31.121","url":null,"abstract":". Many observations have been conducted to clarify the relation between electromagnetic phenomena and seismic activities. We have been observing seismic electromagnetic waves in FM broadcasting frequency band from 76 MHz to 90 MHz using PLL type synthesized digital FM tuners since 1998. We are operating thirteen observatories in Japan. From observations at Ibaraki by the dual frequency method using two different frequencies, nine events of co-seismic electromagnetic waves were observed for seven years from January 1, 2002 to December 31, 2008. Received electromagnetic levels rose up at the same moment of arrival of seismic waves. Further, we examined the relation between the co-seismic broadband electromagnetic waves and the seismic parameters. It was confirmed that the detected peak electromagnetic levels were well correlated with the peak ground accelerations of the earthquakes.","PeriodicalId":274637,"journal":{"name":"Journal of atmospheric electricity","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128094135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"VLF amplitude anomaly during the total solar eclipse of 22 July, 2009","authors":"V. Chauhan, Birbal Singh","doi":"10.1541/JAE.30.95","DOIUrl":"https://doi.org/10.1541/JAE.30.95","url":null,"abstract":"","PeriodicalId":274637,"journal":{"name":"Journal of atmospheric electricity","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132349217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Y. Kasahara, T. Nakamura, Y. Hobara, M. Hayakawa, A. Rozhnoi, M. Solovieva, O. Molchanov
Though there have been several papers suggesting the important role of atmospheric gravity waves (AGWs) in the generation mechanism of seismo-ionospheric perturbations, no reports have appeared on the statistical study of the AGW effect. Based on the data over nine years and for many propagation paths in and around Japan, this paper presents the first statistical result on the role of AGW in seismo-ionospheric effects. The conclusion by means of superimposed epoch analysis is that the AGW modulation (fluctuation) is rather enhanced about 10 days only for shallow (depth < 40km) earthquakes, but its significance level is just close to the conventional 2sigma (sigma: standard deviation) level. So that, we can conceive that the AGW channel is the most dominant hypothesis for seismo- ionospheric perturbations, but an alternative channel such as chemical (+ electric field) channel is also operative either simultaneously for an EQ or may be dominant for a small number of earthquakes.
{"title":"A statistical study on the AGW modulations in subionospheric VLF/LF propagation data and consideration of the generation mechanism of seismo-ionospheric perturbations","authors":"Y. Kasahara, T. Nakamura, Y. Hobara, M. Hayakawa, A. Rozhnoi, M. Solovieva, O. Molchanov","doi":"10.1541/JAE.30.103","DOIUrl":"https://doi.org/10.1541/JAE.30.103","url":null,"abstract":"Though there have been several papers suggesting the important role of atmospheric gravity waves (AGWs) in the generation mechanism of seismo-ionospheric perturbations, no reports have appeared on the statistical study of the AGW effect. Based on the data over nine years and for many propagation paths in and around Japan, this paper presents the first statistical result on the role of AGW in seismo-ionospheric effects. The conclusion by means of superimposed epoch analysis is that the AGW modulation (fluctuation) is rather enhanced about 10 days only for shallow (depth < 40km) earthquakes, but its significance level is just close to the conventional 2sigma (sigma: standard deviation) level. So that, we can conceive that the AGW channel is the most dominant hypothesis for seismo- ionospheric perturbations, but an alternative channel such as chemical (+ electric field) channel is also operative either simultaneously for an EQ or may be dominant for a small number of earthquakes.","PeriodicalId":274637,"journal":{"name":"Journal of atmospheric electricity","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2010-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121455499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：