An adjoint of a regional chemical transport model is used to calculate location-specific temperature influences (climate penalties) on two policy-relevant ozone metrics: concentrations in polluted regions (>65 ppb) and short-term mortality in Canada and the U.S. Temperature influences through changes in chemical reaction rates, atmospheric moisture content, and biogenic emissions exhibit significant spatial variability. In particular, high-NO x, polluted regions are prominently distinguished by substantial climate penalties (up to 6.2 ppb/K in major urban areas) as a result of large temperature influences through increased biogenic emissions and nonnegative water vapor sensitivities. Temperature influences on ozone mortality, when integrated across the domain, result in 369 excess deaths/K in Canada and the U.S. over a summer season - an impact comparable to a 5% change in anthropogenic NOx emissions. As such, we suggest that NOx control can be also regarded as a climate change adaptation strategy with regard to ozone air quality. Key Points Ozone climate penalties in North America show great spatial variability High-NOx regions are among locations with the largest climate penalties NOx control can be seen as a climate change adaptation strategy

adjoint, climate penalty, mortality, ozone
Geophysical Research Letters
Department of Civil and Environmental Engineering

Zhao, S. (Shunliu), Pappin, A.J. (Amanda J.), Morteza Mesbah, S. (S.), Joyce Zhang, J.Y. (J. Y.), Macdonald, N.L. (Nicole L.), & Hakami, A. (2013). Adjoint estimation of ozone climate penalties. Geophysical Research Letters, 40(20), 5559–5563. doi:10.1002/2013GL057623