We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Photodissociation of particulate nitrate as a source of daytime tropospheric Cl<sub>2</sub>.
- Authors
Peng, Xiang; Wang, Tao; Wang, Weihao; Ravishankara, A. R.; George, Christian; Xia, Men; Cai, Min; Li, Qinyi; Salvador, Christian Mark; Lau, Chiho; Lyu, Xiaopu; Poon, Chun Nan; Mellouki, Abdelwahid; Mu, Yujing; Hallquist, Mattias; Saiz-Lopez, Alfonso; Guo, Hai; Herrmann, Hartmut; Yu, Chuan; Dai, Jianing
- Abstract
Chlorine atoms (Cl) are highly reactive and can strongly influence the abundances of climate and air quality-relevant trace gases. Despite extensive research on molecular chlorine (Cl2), a Cl precursor, in the polar atmosphere, its sources in other regions are still poorly understood. Here we report the daytime Cl2 concentrations of up to 1 ppbv observed in a coastal area of Hong Kong, revealing a large daytime source of Cl2 (2.7 pptv s−1 at noon). Field and laboratory experiments indicate that photodissociation of particulate nitrate by sunlight under acidic conditions (pH < 3.0) can activate chloride and account for the observed daytime Cl2 production. The high Cl2 concentrations significantly increased atmospheric oxidation. Given the ubiquitous existence of chloride, nitrate, and acidic aerosols, we propose that nitrate photolysis is a significant daytime chlorine source globally. This so far unaccounted for source of chlorine can have substantial impacts on atmospheric chemistry. This study unravels an important daytime Cl2 source in the extra-polar atmosphere and shows that photolysis of particle nitrate at high acidity produced unprecedented levels of Cl2, boosting the oxidative power and air pollutants like O3.
- Subjects
HONG Kong (China); PARTICULATE nitrate; PHOTODISSOCIATION; ATMOSPHERIC chemistry; TRACE gases; AIR pollutants; TROPOSPHERIC chemistry; AEROSOLS
- Publication
Nature Communications, 2022, Vol 13, Issue 1, p1
- ISSN
2041-1723
- Publication type
Article
- DOI
10.1038/s41467-022-28383-9