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Volume 34 (2014)
- Issue 2 Pages 69-
- Issue 1 Pages 1-
Volume 34, Issue 2
Displaying 1-3 of 3 articles from this issue
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Manoj Kumar, Birbal Singh2014 Volume 34 Issue 2 Pages 69-77
Published: 2014
Released on J-STAGE: August 28, 2014
JOURNAL FREE ACCESSEmploying a system of 3-component search coil magnetometer installed in a remote area in the out skirt of Agra (Geographic lat.27.2°N, long.78°E), India, Schumann resonance (SR) observations have been in progress since 01 April, 2007. In this paper we analyze the first mode intensity data for a period of one year between 01 March, 2011 and 29 February, 2012 and correlate with ground surface temperature (GST) for low latitude region between ± 30° latitude.The GST data are taken from the website: http://www.tutiempo.net. Our results show that the variation curves of the two sets of data match satisfactorily with cross-correlation coefficient of 0.522 which is consistent with earlier workers for low latitude region. We also carry out linear regression analysis and regression equation is utilized to verify the calculated and measured GST which are found to be matching satisfactorily also.View full abstractDownload PDF (1025K) -
Kyosuke Ishii, Syugo Hayashi, Fumiaki Fujibe2014 Volume 34 Issue 2 Pages 79-86
Published: 2014
Released on J-STAGE: August 28, 2014
JOURNAL FREE ACCESSThe 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.View full abstractDownload PDF (689K) -
Tomoki Higuchi, Nozomi Haga, Kuniyuki Motojima2014 Volume 34 Issue 2 Pages 87-100
Published: 2014
Released on J-STAGE: August 28, 2014
JOURNAL FREE ACCESSRecently, electromagnetic phenomena associated with earthquakes have gotten a lot of attention. So, we have been observed VHF band propagation for long timeand analyzed statistical relation between anomalous line-of-sight propagation in the VHF band and occurrences of earthquakes using quantitative evaluation. Now, we need to detect the anomalous propagation from received data. Therefore, we used a statistical analysis to judge anomalous propagation in a previous study. In this paper, we judged the anomalous propagation by continuous wavelet transform and evaluated the relationship with earthquakes. Furthermore, we introduced hit rate and alarm rate to simplify the relationship between anomalous propagation and earthquakes. As a result, relation between anomalous propagation and earthquakes became clear.View full abstractDownload PDF (828K)
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