Unexpected wildfire emission impacts air quality worldwide

Unexpected wildfire emission impacts air quality worldwide
Credit: University of Colorado at Boulder

In lab studies of wildfire, nitrous acid seems like a minor actor, often underrepresented in atmospheric models. But in the real-world atmosphere, during wildfires, the chemical plays a leading role—spiking to levels significantly higher than scientists expected, driving increased ozone pollution and harming air quality, according to a new study led by the University of Colorado Boulder and the Belgian Institute for Space Aeronomy.


“We found nitrous acid levels in wildfire plumes worldwide are two to four times higher than expected,” said Rainer Volkamer, CIRES Fellow, professor of chemistry at CU Boulder and co-lead author on the Nature Geoscience study. “The chemical can ultimately drive the formation of lung- and crop-damaging ozone pollution downwind of fires.”

Nitrous acid in wildfire smoke is accelerating the formation of an oxidant, the hydroxyl radical or OH. Unexpectedly, nitrous acid was responsible for around 60 percent of OH

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‘Dayglow’ at Rosetta’s comet turns out to be unexpected ultraviolet aurora

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Comet Chury in all its glory


ESA/Rosetta/NAVCAM

Auroras, better known to we Earthlings as northern or southern lights, aren’t limited to planets and moons. For the first time, scientists have identified the same phenomenon at a comet.

The discovery comes courtesy of the European Space Agency’s Rosetta mission, which famously landed on the comet 67P/Churyumov-Gerasimenko, also known as Comet Chury, back in 2014. 

On Earth, we get auroras when energetic particles from the solar wind interact with our planet’s magnetosphere. When researchers looked at Chury in the far ultraviolet range of the electromagnetic spectrum, they were able to pick up a similar effect from solar wind electrons striking the cloud of gas, or coma, around the comet’s rocky nucleus.

“The resulting glow is one of a kind,” says Marina Galand of Imperial College

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