Atmospheric tester

Scientists at the US Department of Energy's Brookhaven National Laboratory have developed a new tool for quantitatively measuring elusive atmospheric chemicals that play a key role in the formation of photochemical smog.

Better measurements will improve scientists' understanding of the mechanisms of smog formation and their ability to select and predict the effectiveness of various mitigation strategies.

The device measures atmospheric hydroperoxyl radicals - short-lived, highly reactive intermediates involved in the formation of ozone, a component of photochemical smog - in the lowest layer of Earth's atmosphere.

The levels of these radicals can indicate which of a variety of chemical pathways is predominant in converting basic starting ingredients - hydrocarbons, nitrogen oxides, and water vapour - into smog in the presence of sunlight.

'Understanding the relative importance of the various pathways can help you tailor your mitigation strategies,' said Brookhaven atmospheric chemist Stephen Springston, one of the inventors. 'For example, are you better off spending your money reducing hydrocarbon emissions or nitrogen oxide emissions?'