Spatial variations of particulate-bound mercury in the atmosphere along a transect from the mid-Northern Hemisphere to the high southern latitudes. (1st February 2023)

• Record Type: Journal Article
• Authors: Wu, Guangmei; Shi, Guitao; Li, Chuanjin; Hu, Ye; Ma, Hongmei; Chen, Zhenlou
• Is Part Of: Atmospheric environment. Volume 294(2023)
• Publication Date: 2023-02-01
• Subjects: Aerosol -- Particulate-bound mercury -- Latitudinal gradient -- Antarctica; Air -- Pollution -- Periodicals; Air -- Pollution -- Meteorological aspects -- Periodicals; 551.51
• DOI: 10.1016/j.atmosenv.2022.119470
• Languages: English
• ISSNs: 1352-2310

Abstract

Abstract: Particulate-bound mercury (PBM) measurements in the boundary layer were performed during the 2015–2016 Chinese Antarctic Research Expedition from the middle Northern Hemisphere (Shanghai, China) to the Antarctic Ice Sheet summit, Dome A. A significant latitudinal gradient in PBM was observed. PBM over the Northern Hemisphere oceans was influenced by both continental and oceanic sources, with elevated PBM levels associated with continental inputs. PBM over this region was significantly higher in November than that in April, which could be related to the continental Hg carried by the strong East Asian winter monsoon. Far away from the continental sources, extremely low PBM was observed over the Southern Ocean (2.6 ± 1.6 pg m −3 ). Elevated PBM was found across the Antarctic Ice Sheet (79.1 ± 43.4 pg m −3 ), and the highest PBM observed at Dome A (143.4 ± 27.0 pg m −3 ) was likely associated with GEM emissions from snow and enhanced oxidation of GEM due to snow photochemistry. Across the Antarctic Ice Sheet, PBM increased significantly with the increasing distance from the coast, which may have resulted from the mixing of air masses from the Antarctic plateau and the ocean. GEM emissions from inland Antarctic snow can influence atmospheric PBM concentrations over the Antarctic coastal seas via the transport by katabatic winds, and thus play an important role in atmospheric Hg cycle in the high southern latitudes. Graphical abstract: Image 1 Highlights: PBM over the Northern Hemisphere oceans was associated with continental inputs. The lowest PBM was observed over the Southern Ocean. PBM increased with the increasing distance from coast over East Antarctic ice sheet. High PBM on East Antarctic plateau may be related to strong snow photochemistry.