Photolysis of Particulate Nitrate as a Source of HONO and NOx

• DOI: 10.1021/acs.est.7b00387
• Publication Date: 2017-05-15T22:57:14Z
• Authors: Chunxiang Ye; Ning Zhang; Honglian Gao; Xianliang Zhou
• Keywords: Nitrates; Photolysis; 13. Climate action; Nitrogen Dioxide; Nitrogen Oxides; Nitrous Acid; 01 natural sciences; 0105 earth and related environmental sciences

Photolysis of nitric acid on the surface has been found recently to be greatly enhanced from that in gas phase. Yet, photolysis particulate nitrate (pNO3) associated with atmospheric aerosols is still relatively unknown. Here, aerosol filter samples were collected both near ground and throughout troposphere board NSF/NACR C-130 aircraft. The rate constants pNO3 determined these by directly monitoring production rates nitrous (HONO) nitrogen dioxide (NO2) under UV light (>290 nm) irradiation. Scaled tropical noontime condition level (solar zenith angle = 0°), normalized (jpNO3N) are range 6.2 × 10-6 s-1 5.0 10-4 a median 8.3 10-5 mean (±1 SD) (1.3 ± 1.2) s-1. Chemical compositions, specifically loading organic matter, affect photolysis. Extrapolated ambient conditions, e.g. ≤ 10 nmol m-3, jpNO3N value over 1.8 suburban, rural, remote environments. thus source HONO NO2 troposphere.