Isotopic compositions of atmospheric total gaseous mercury in 10 Chinese cities and implications for land surface emissions

Xuewu Fu, Chen Liu, Hui Zhang, Yue Xu, Hui Zhang, Jun Li, Xiaopu Lyu, Gan Zhang, Hai Guo, Xun Wang, Leiming Zhang, Xinbin Feng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

Land surface emissions are an important source of atmospheric total gaseous mercury (TGM); however, its role on the variations of TGM isotopic compositions and concentrations has not been properly evaluated. In this study, TGM isotope compositions, a powerful tracer for sources and transformation of Hg, were measured at 10 urban sites and one rural site in China. TGM concentrations were higher in summer than in winter in most cities except in Guiyang and Guangzhou in the low latitudes. The summertime high TGM concentrations coincided with prevailing low TGM δ202Hg and high TGM Δ199Hg signatures. These seasonal patterns were in contrast with those typically observed in rural areas in the Northern Hemisphere, suggesting that atmospheric oxidation chemistry, vegetation activity and residential coal combustion were likely not the dominant mechanisms contributing to the TGM concentration and isotopic composition seasonality in Chinese cities. The amplitudes of seasonal variations in TGM concentrations and Δ199Hg (or TGM δ202Hg) were significantly positively (or negatively) correlated with that of the simulated soil GEM emission flux. These results suggest that the seasonal variations in TGM isotopic compositions and concentrations in the 10 Chinese cities were likely controlled by land surface emissions that were observed or reported with highly negative δ202Hg signatures.

Original languageEnglish
Pages (from-to)6721-6734
Number of pages14
JournalAtmospheric Chemistry and Physics
Volume21
Issue number9
DOIs
Publication statusPublished - 4 May 2021

ASJC Scopus subject areas

  • Atmospheric Science

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