Nature Reports Climate Change, published online 12 November 2009; doi: 10.1038/climate.2009.117
Unlucky strike
by Stephanie Baudains
ISTOCKPHOTO / C. SPENCER
Lightning storms at mid-latitudes and in the subtropics produce more nitrogen oxides (NOx) than previously thought, finds a new study. What's more, most of the NOx pollution — a precursor to the greenhouse gas ozone — ends up in the upper troposphere, where it has a strong influence on climate.
A team led by Lesley Ott of NASA's Goddard Earth Sciences and Technology Center in Greenbelt, Maryland, used data collected during lightning storms in Germany and the United States between 1985 and 2002, along with a cloud simulation model, to estimate the amount of NOx produced by an average flash of lightning. They found that a single lightning strike produces about 7 kilograms of chemically reactive NOx. Worldwide, this amounts to an annual production of 8.6 million metric tonnes. As none of the data were collected in the tropics — where lightning may yield less NOx per flash — the global estimate may be on the high end, say the researchers.
They speculate, however, that if lightning storms become more frequent in the future, as predicted by some theoretical models, increased NOx in the upper atmosphere could affect global climate change.
See also:
See also:
Ott, L., K. Pickering, G. Stenchikov, D. Allen, A. DeCaria, B. Ridley, R.-F. Lin, S. Lang, and W.-K. Tao (2009), Production of lightning NOx and its vertical distribution calculated from 3-D cloud-scale chemical transport model simulations, J. Geophys. Res., doi: 10.1029/2009JD011880, in press.
[PDF] (accepted 15 October 2009)
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