Villigen 5232;
Switzerland;
Institute for Atmospheric and Earth System Research/Physics;
Paul Scherrer Institute;
Department of Atmospheric Sciences;
Pittsburgh;
California Institute of Technology;
Villeurbanne 69626;
IRCELYON;
Pasadena;
Washington 98195;
University of Washington;
Carnegie Mellon University;
California 91125;
Center far Atmospheric Particle Studies;
United States||Division of Chemistry and Chemical Engineering;
Helsinki 00014;
United States;
Univ Lyon;
CNRS;
Finland;
University of Helsinki;
France;
Universite Claude Bernard Lyon 1;
Pennsylvania 15213;
Seattle;
Laboratory of Atmospheric Chemistry;
Faculty of Science;
关键词：
new particle formation;
mass spectrometry;
biogenic compounds;
gas phase chemistry;
期刊名称：
Environmental Science & Technology: ES&T
i s s n：
0013-936X
年卷期：
2024 年
58 卷
3 期
页 码：
1601-1614
页 码：
摘 要：
Highly oxygenated organic molecules (HOMs) are a major source of new particles that affect the Earth's climate. HOM production from the oxidation of volatile organic compounds (VOCs) occurs during both the day and night and can lead to new particle formation (NPF). However, NPF involving organic vapors has been reported much more often during the daytime than during nighttime. Here, we show that the nitrate radicals (NO,), which arise predominantly at night, inhibit NPF during the oxidation of monoterpenes based on three lines of observational evidence: NPF experiments in the CLOUD (Cosmics Leaving Outdoor Droplets) chamber at CERN (European Organization for Nuclear Research), radical chemistry experiments using an oxidation flow reactor, and field observations in a wetland that occasionally exhibits nocturnal NPF. Nitrooxy-peroxy radicals formed from NO, chemistry suppress the production of ultralow-volatility organic compounds (ULVOCs) responsible for biogenic NPF, which are covalently bound peroxy radical (RO_2) dimer association products. The ULVOC yield of α-pinene in the presence of NO_3 is one-fifth of that resulting from ozone chemistry alone. Even trace amounts of NO_3 radicals, at sub-parts per trillion level, suppress the NPF rate by a factor of 4. Ambient observations further confirm that when NO_3 chemistry is involved, monoterpene NPF is completely turned off. Our results explain the frequent absence of nocturnal biogenic NPF in monoterpene (α-pinene)-rich environments.
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