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The Catatumbo Lightning (Spanish: ''Relámpago del Catatumbo'')〔(【引用サイトリンク】title=Fogonazos: Catatumbo, the everlasting storm )〕 is an atmospheric phenomenon in Venezuela. It occurs only over the mouth of the Catatumbo River where it empties into Lake Maracaibo. The frequent, powerful flashes of lightning over this relatively small area are considered to be the world's largest single generator of tropospheric ozone.〔(【引用サイトリンク】url=http://wayback.archive.org/web/20080623062805/http://www.meteogroup.co.uk/uk/home/weather/weather_news/news_archive/archive/2007/november/ch/f540146dcc/article/fire_in_the_sky.html )〕 It originates from a mass of storm clouds at a height of more than 5 km, and occurs during 140 to 160 nights a year, 10 hours per day and up to 280 times per hour. It occurs over and around Lake Maracaibo, typically over the bog area formed where the Catatumbo River flows into the lake. After appearing continually for centuries, the lightning ceased from January to April 2010, apparently due to drought, temporarily raising fears that it might have been extinguished permanently.〔(【引用サイトリンク】title=Catatumbo Lightning )〕 == Location and formation mechanism == The Catatumbo lightning usually develops between the coordinates and . The storms (and associated lightning) are likely the result of the winds blowing across the Maracaibo Lake and surrounding swampy plains. These air masses inevitably meet the high mountain ridges of the Andes, the Perijá Mountains (3,750 m), and Mérida's Cordillera, enclosing the plain from three sides. The heat and moisture collected across the plains creates electrical charges and, as the air masses are destabilized at the mountain ridges, result in almost continual thunderstorm activity.〔 The phenomenon is characterized by almost continuous lightning, mostly within the clouds, which is produced in a large vertical development of clouds that form large electric arcs between 2 and 10 km in height (or more). The lightning tends to start approximately one hour after dusk. Among the major modern studies there is the one done by Melchor Centeno, who attributes the origin of the thunderstorms to closed wind circulation in the region. Between 1966 and 1970, Andrew Zavrostky investigated the area three times, with assistance from the University of the Andes. He concluded that the lightning has several epicenters in the marshes of Juan Manuel de Aguas National Park, Claras Aguas Negras, and west Lake Maracaibo. In 1991 he suggested that the phenomenon occurred due to cold and warm air currents meeting around the area. The study also speculated that an isolated cause for the lightning might be the presence of uranium in the bedrock. Between 1997 and 2000 Nelson Falcón conducted several studies, and produced the first microphysics model of the Catatumbo Lightning. He identified the methane produced by the swamps and the oil deposits in the area as a major cause of the phenomenon. It has been noted to have little effect on local flora such as ferns, despite concerns. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Catatumbo lightning」の詳細全文を読む スポンサード リンク
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