Using old numerical techniques with a new climate-science approach, a paper from UC Irvine has created a solid, quantitative link between measurements at the thousands of surface air-pollution stations and the global chemistry-climate models that we use to project future air quality. This innovative technique provides air-pollution data on the same scales as the global models, including the full statistics of clean-air versus extreme pollution episodes.

A surprising result is that surface ozone extremes tend to occur as multi-day, 1000-km mega-pollution episodes over the USA and Europe, and moreover, the UCI chemistry model was able to predict their occurrence with skill.