Lightning effects

Bruce Railsback of Georgia University, Athens, USA, has concluded that lightning increases the acidity in rain. This was discovered while studying the change in the acidity of rainfall during a storm. Railsback gathered 132 samples of falling rain at intervals of 90 seconds in north-eastern Georgia. Samples collected while thunder was flashing had an average p H of 3.63, sharply more acidic than the average of 4.05 for rain that fell when the skies were silent. Lightning can increase the production of the reactive chemicals that are needed to oxidise gases like sulphur dioxide and nitrogen dioxide into acid, explains Railsback ( New Scientist , Vol 154, No 2084).