Environment Research Institute, Shandong University, Qingdao, 266237, China
Abstract. There is chromophore dissolved organic matter (CDOM) in the atmosphere, which may form triplet-state chromophoric dissolved organic matter (3CDOM*) to further driving the formation of reactive oxygen species (ROS) under solar illumination. 3CDOM* contributes significantly to aerosol photochemistry and plays an important role in aerosol aging. We quantify the ability to form 3CDOM* and drive the formation of ROS by primary, secondary and ambient aerosols. Biomass combustion has the strongest 3CDOM* generation capacity and the weakest vehicle emission capacity. Ambient aerosol has a stronger ability to generate 3CDOM* in winter than in summer. Most of the triplet states generation conform to first-order reaction, but some of them do not due to the different quenching mechanism. The structural-activity relationship between the CDOM type and the 3CDOM* formation capacity shows that the two types of CDOM identified, which similar to the nitrogen-containing chromophores contributed 88 % to the formation of 3CDOM*. The estimated formation rate of 3CDOM* can reach ~ 100 μmol m−3 h−1 in the atmosphere in Xi'an, China, which is approximately one hundred thousand-times the hydroxyl radical (•OH) production. This study verified that 3CDOM* drives at least 30 % of the singlet oxygen (1O2) and 31 % of the •OH formed by aerosols using the spin trapping and electron paramagnetic resonance technique.
This preprint has been withdrawn.
How to cite. Chen, Q., Mu, Z., Xu, L., Wang, M., Wang, J., Shan, M., Yang, X., Fan, X., Song, J., Wang, Y., Lin, P., Zhang, L., Shen, Z., and Du, L.: Triplet State Formation of Chromophoric Dissolved Organic Matter in Atmospheric Aerosols: Characteristics and Implications, Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2019-1032, 2020.
Received: 11 Nov 2019 – Discussion started: 24 Jan 2020
It is important to study the formation characteristics and mechanism of triplet state in aerosols to quantify the effect of chromophore substances on the global climate and atmospheric environmental quality. The result of this study reveals that chromophore substances contributes significantly to aerosol photochemistry and plays an important role in aerosol aging. The global models may need to include those potential effects in the future.
It is important to study the formation characteristics and mechanism of triplet state in...