'With the help of a great undergraduate intern,' said Brune, 'we were able to link the huge signals seen by our instrument flying through the thunderstorm clouds to the lightning measurements made from the ground.'

Then they did a reanalysis of the thunderstrom and lightning dataset. The data was from an instrument on a plane flown above Colorado and Oklahoma in 2012 looking at the chemical changes that thunderstorms and lightning make to the atmosphere.īut a few years ago, Brune took the data off the shelf, saw that the signals were really hydroxyl and hydroperoxyl, and then worked with a graduate student and research associate to see if these signals could be produced by sparks and subvisible discharges in the laboratory. 'We assumed there was noise in the instrument, so we removed the huge signals from the dataset and shelved them for later study.' Brune, distinguished professor of meteorology at Penn State.

'Initially, we looked at these huge OH and HO 2 signals found in the clouds and asked, what is wrong with our instrument?' said William H. OH is the main driver of many compositional changes in the atmosphere. The hydroxyl radical is important in the atmosphere because it initiates chemical reactions and breaks down molecules like the greenhouse gas methane.

Does heat lightning produce thunder