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Fire and lightning

点击量:   时间:2019-03-08 11:04:00

SMOKE from forest fires raging in Mexico this spring mysteriously affected lightning in the central US. Normally, about 10 per cent of lightning is “positive”, when electrons stream up from the Earth to clouds. These strikes are more destructive than negative ones moving the opposite way. However, figures from the US National Lightning Data Network show that the fraction of positive strikes tripled during smoky periods. Walter Lyons of FMA Research in Fort Collins, Colorado, says the smoke may affect charge development (Science, vol 282, p 77). “But we don’t really understand the details,