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Ozone detection ‘is all about location’

Major new research has revealed that location is the single most significant factor in ozone detection, with areas where temperature and light levels are higher exhibiting greater levels of the gas.

Heat and light levels indicate ozone production

Scientists at the University of North Carolina at Chapel Hill mapped the extent to which gas emissions convert into ozone in different parts of the world. They found the heat and light levels on the equator lead to the highest rate of ozone production – making location the determining factor in driving ozone levels. Jason West, who led the study, said: “We thought that location was going to be important, but we didn’t suspect it would be the most important factor contributing to total ozone levels worldwide. “Our findings suggest that where the world emits is more important than how much it emits.”

How is ozone formed and detected?

Ozone is not directly emitted, but is formed due to reactions with nitrogen oxides in the air, typically from vehicle exhausts and industrial sources. Ultraviolet light in the atmosphere triggers the process by which these nitrogen oxides convert into ozone – and in places where light levels are more intense, and in the presence of more heat, this reaction occurs faster. This effect is exacerbated further by the air currents in hotter locations, which carry the ozone higher into the atmosphere where it persists for longer.

Global future impact

Owen Cooper, who also worked on the study, said that if greenhouse gas emissions shift towards the equator, this could offset or even counteract efforts to reduce the total quantity of global emissions, leading to no decrease in ozone levels in the atmosphere. He added that ozone detection in the tropics from commercial aircraft passes and satellite observations will help to monitor the situation, while influencing future decision making in terms of how to act to prevent ozone build-up in the atmosphere.