Observed suppression of ozone formation at extremely high temperatures due to chemical and biophysical feedbacks

Observed suppression of ozone formation at extremely high temperatures due to chemical and biophysical feedbacks [1]

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Ground level ozone concentrations ([O3]) typically show a direct linear relationship with surface air temperature. Three decades of California measurements provide evidence of a statistically significant change in the ozone-temperature slope (?mO3-T) under extremely high temperatures (> 312 K). This ?mO3-T leads to a plateau or decrease in [O3], reflecting the diminished role of nitrogen oxide sequestration by peroxyacetyl nitrates and reduced biogenic isoprene emissions at high temperatures. Despite inclusion of these processes in global and regional chemistry-climate models, a statistically significant change in ?mO3-T has not been noted in prior studies. Future climate projections suggest a more frequent and spatially widespread occurrence of this ?mO3-T response, confounding predictions of extreme ozone events based on the historically observed linear relationship.

Publication Date:

15/11/2010

Author(s): Allison L. Steiner [2], Adam J. Davis [3], Sanford Sillman & et al [4]

Source: Proceedings of the National Academy of Sciences [5]

Vol:

107

Issue:

pp:

19685

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