Biogenic 2‐methyl‐3‐buten‐2‐ol increases regional ozone and HO x sources

We present the first regional‐scale chemistry simulation investigating the effects of biogenic 2‐methyl‐3‐buten‐2‐ol (MBO) emissions on air quality. In a central California model domain, MBO emissions have a distinctly different regional pattern than isoprene but have similar daily maxima of about 5 mg m −2 hr −1 . MBO oxidation causes an increase in ozone, formaldehyde, acetone and consequently hydrogen radical production (PHO x ). The addition of MBO increases the daily maximum ozone as much as 3 ppb near source regions (2–5% in rural areas) and as much as 1 ppb in the Central Valley. Formaldehyde concentrations increase by as much as 1 ppb (40%) over the Sierra Nevada Mountains, increasing the production of HO x by 10–20% and accelerating local chemistry. This indicates that inclusion of MBO and other biogenic oxygenated emissions in regional simulations in the western and southeastern United States is essential for accurate representation of ozone and HO x .