Catatumbo lightning

The Catatumbo Lightning (Spanish Relámpago del Catatumbo)[1] is an atmospheric phenomenon in Venezuela. It occurs strictly in an area located 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[2] which refers to ozone that does not replenish the stratospheric ozone layer.[3]

It originates from a mass of storm clouds that create a voltaic arc at more than 5 km of height, 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.[4]

After appearing continually for centuries, the lightning ceased from January to April 2010, apparently due to drought.[5] This raised fears that it might have been extinguished permanently.[6] The lightning reappeared after a two month period and continues to be seen today.

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Location and formation mechanism

The Catatumbo lightning usually develops between the coordinates 8°30' and 9°45'N and 71° and 73°W.

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 (3,750m), 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, resulting in almost continual thunderstorm activity.[5]

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 Los Andes. He concluded that the lightning would have several epicentres 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.[7]

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.[8] It has been noted to have little effects on local flora such as ferns, despite concerns.[9]

Historical references

The first written mention of the Catatumbo lightning was in the epic poem "La Dragontea" (1597) by Lope de Vega, which recounts the defeat of English raider Sir Francis Drake.

The Prussian naturalist and explorer Alexander von Humboldt once described it as "electrical explosions that are like phosphorescent gleam." Italian geographer Agustin Codazzi described it as a "lightning that seems to arise from the continued Zulia river and its surroundings."

The phenomenon became so celebrated that it was depicted in the flag and coat of arms of the state of Zulia, which contains Lake Maracaibo, and mentioned in the state's anthem.

This phenomenon has been popularly known for centuries as the Lighthouse of Maracaibo, since it is visible for miles around Lake Maracaibo.[10]

References

External links