Chemical Evolution of Atmospheric Organic Carbon over Multiple Generations of Oxidation

Isaacman-VanWertz, Gabriel ; Massoli, Paola ; O'Brien, Rachel ; Lim, Christopher ; Franklin, Jonathan P ; Moss, Joshua A ; Hunter, James F ; Nowak, John B[Point of Contact] ; Canagaratna, Manjula R ; Misztal, Pawel K(California Univ, Dept of Environmental Science, Berkeley, CA, United States)

关键词: AGING (MATERIALS);    ATMOSPHERIC CHEMISTRY;    ATMOSPHERIC COMPOSITION;    ATMOSPHERIC EFFECTS;    CARBON;    CHEMICAL EVOLUTION;    FRAGMENTATION;    OXIDATION;    OXIDIZERS;    OZONE;    PARTICULATES;    REACTIVITY;    VOLATILITY;   

RP-ID  :  NF1676L-27280

学科分类：污染

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

The evolution of atmospheric organic carbon (OC) as it undergoes oxidation has a controlling influence on concentrations of key atmospheric species, including particulate matter, ozone, and oxidants. However, the full characterization of OC over hours to days of atmospheric processing has been stymied by its extreme chemical complexity. Here we study the multigenerational oxidation of α-pinene in the laboratory, characterizing products with several state-of-the-art analytical techniques. While quantification of some early-generation products remains elusive, full carbon closure is achieved (within uncertainty) by the end of the experiments. This enables new insights into the effects of oxidation on OC properties (volatility, oxidation state, and reactivity), and the atmospheric lifecycle of OC. Following an initial period characterized by functionalization reactions and particle growth, fragmentation reactions dominate, forming smaller species. After approximately one day of atmospheric aging, most carbon is sequestered in two long-lived reservoirs, volatile oxidized gases and low-volatility particulate matter.