2.27 Closing the Peroxy Acetyl (PA) Radical Budget: Observations of Acyl Peroxy Nitrates (PAN, PPN, and MPAN) During BEARPEX 2007

摘要

Acyl peroxy nitrates (APNs, also known as PANs) are an important class of reactive nitrogen species having the general structure: RC(O)OONO_2. In urban source regions, APN production acts as a net sink for NO_x (NO_x = NO + NO_2). Under high NO_x (VOC-limited) conditions this temporary sink results in increased ozone production rates by slowing the rate of OH reaction with NO_2, and thus extending the HO_x (HO_x = OH + HO_2) chain length. Downwind of the source region, where total NO_x levels have decreased, APN decomposition injects NO_x into the atmosphere under low NO_x conditions resulting in increased ozone prouction rates.