Seasonal Variation of Mercury and Its Isotopes in Atmospheric Particles at the Coastal Zhongshan Station, Eastern Antarctica

• Published in: Environmental Science & Technology
• Main Authors: Li, Chuanjin, Chen, Jiubin, Angot, Hélène, Zheng, Wang, Shi, Guitao, Ding, Minghu, Du, Zhiheng, Zhang, Qianggong, Ma, Xiangyu, Kang, Shichang, Xiao, Cunde, Ren, Jiawen, Qin, Dahe
• Other Authors: Institute of Arctic Alpine Research University of Colorado Boulder (INSTAAR), University of Colorado Boulder
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: [SDE]Environmental Sciences; [SDE.ES]Environmental Sciences/Environment and Society; [SDE.MCG]Environmental Sciences/Global Changes; [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces; environment; [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Antarctic; The Antarctic; Zhongshan; Zhongshan Station; Antarc*; Antarctica
• Online Access: https://hal.science/hal-04382834; https://doi.org/10.1021/acs.est.0c04462

International audience Mercury (Hg) is a globally spread trace metal due to its long atmospheric residence time. Yet, our understanding of atmospheric processes (e.g., redox reactions and deposition) driving Hg cycling is still limited, especially in polar regions. The Antarctic continent, by virtue of its remoteness, is the perfect location to investigate Hg atmospheric processes in the absence of significant local anthropogenic impact. Here, we present the first 2 year record (2016-2017) of total suspended particulate mercury (PHg) concentrations along with a year-round determination of an Hg stable isotopic composition in particles collected at Zhongshan Station (ZSS), eastern Antarctic coast. The mean PHg concentration is 21.8 ± 32.1 pg/m 3 , ranging from 0.9 to 195.6 pg/ m 3 , and peaks in spring and summer. The negative mass-independent fractionation of odd Hg isotopes (odd-MIF, average-0.38 ± 0.12‰ for Δ 199 Hg) and the slope of Δ 199 Hg/Δ 201 Hg with 0.91 ± 0.12 suggest that the springtime isotope variation of PHg is likely caused by in situ photo-oxidation and reduction reactions. On the other hand, the increase of PHg concentrations and the observed odd-MIF values in summer are attributed to the transport by katabatic winds of divalent species derived from the oxidation of elemental Hg in the inland Antarctic Plateau.