Uptake selectivity of Methanesulfonic Acid (MSA) on fine particles over polynya regions of the Ross Sea, Antarctica

• Main Authors: Yan, Jinpei, Joung, Jinyoung, Zhang, Miming, Bianchi, Federico, Tham, Yee Jun, Xu, Suqing, Lin, Qi, Zhao, Shuhui, Li, Lei, Chen, Liqi
• Format: Text
• Language: English
• Published: 2019
• Subjects: Ross Sea; Antarc*; Antarctica
• Online Access: https://doi.org/10.5194/acp-2019-811; https://www.atmos-chem-phys-discuss.net/acp-2019-811/

The uptake of methanesulfonic acid (MSA) on existing particles is a major route of the particulate MSA formation, however, MSA uptake on different particles is still lack of knowledge. Characteristics of MSA uptake on different aerosol particles were investigated in polynya regions of the Ross Sea, Antarctica. Particulate MSA mass concentrations, as well as aerosol populations and size distributions, were observed simultaneously for the first time to access the uptake of MSA on different particles. The results showed that MSA mass concentration did not always reflect MSA particle population in the marine atmosphere. MSA uptake on aerosol particles increased the particle size and changed aerosol chemical compositions, but did not increase the particle population. The uptake rates of MSA on existing particles were significantly influenced by aerosol chemical properties. The favor uptake of MSA occurred on the sea salt particles, as MSA-Na and MSA-Mg particles were abundant in the Na and Mg particles, accounting for 0.43 ± 0.21 and 0.41 ± 0.20 of the total Na and Mg particles, respectively. However, acidic and hydrophobic particles suppressed the MSA uptake, as MSA-EC and MSA-SO 4 2− accounted only 0.24 ± 0.68 and 0.26 ± 0.47 of the total EC and SO 4 2− particles, respectively. The results extended the knowledge of the formation and environmental behavior of MSA in the marine atmosphere.