| Title | First observation of mercury species on an important water vapor channel in the southeastern Tibetan Plateau |
| Authors | Lin, Huiming Tong, Yindong Yu, Chenghao Chen, Long Yin, Xiufeng Zhang, Qianggong Kang, Shichang Luo, Lun Schauer, James de Foy, Benjamin Wang, Xuejun |
| Affiliation | Peking Univ, Coll Urban & Environm Sci, MOE Lab Earth Surface Proc, Beijing 100871, Peoples R China Tianjin Univ, Sch Environm Sci & Engn, Tianjin 300072, Peoples R China East China Normal Univ, Sch Geog Sci, Shanghai 200241, Peoples R China Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, State Key Lab Cryospher Sci, Lanzhou 730000, Peoples R China Chinese Acad Sci, Inst Tibetan Plateau Res, Key Lab Tibetan Environm Changes & Land Surface P, Beijing 100101, Peoples R China CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing 100085, Peoples R China Chinese Acad Sci, South East Tibetan Plateau Stn Integrated Observa, Lulang 860100, Peoples R China Univ Wisconsin, Dept Civil & Environm Engn, Madison, WI 53718 USA Univ Wisconsin, Wisconsin State Lab Hyg, Madison, WI 53718 USA St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO 63108 USA |
| Keywords | SPECIATED ATMOSPHERIC MERCURY TOTAL GASEOUS MERCURY POLYCYCLIC AROMATIC-HYDROCARBONS ELEMENTAL MERCURY YAK DUNG TRANSBOUNDARY TRANSPORT SPATIAL VARIABILITY BLACK CARBON AIR DEPOSITION |
| Issue Date | 25-Feb-2022 |
| Publisher | ATMOSPHERIC CHEMISTRY AND PHYSICS |
| Abstract | The Tibetan Plateau is generally considered to be a significantly clean area owing to its high altitude; however, the transport of atmospheric pollutants from the Indian subcontinent to the Tibetan Plateau has influenced the Tibetan environments. Nyingchi is located at the end of an important water vapor channel. In this study, continuous monitoring of gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particle-bound mercury (PBM) was conducted in Nyingchi from 30 March to 3 September 2019, to study the influence of the Indian summer monsoon (ISM) on the origin, transport, and behavior of Hg. The GEM and PBM during the preceding Indian summer monsoon (PISM) period (1.20 +/- 0.35 ng m(-3) and 11.4 +/- 4.8 pg m(-3) for GEM and PBM, respectively) were significantly higher than those during the ISM period (0.95 +/- 0.21 ng m(-3), and 8.8 +/- 6.0 pg m(-3)); the GOM during the PISM period (13.5 +/- 7.3 pg m(-3)) was almost at the same level as that during the ISM period (12.7 +/- 14.3 pg m(-3)). The average GEM concentration in the Nyingchi region, obtained using passive sampler, was 1.12 +/- 0.28 ng m(-3) (from 4 April 2019 to 31 March 2020). The GEM concentration showed that the sampling area was very clean compared to other high-altitude sites. The GEM has several patterns of diurnal variation during different periods. Stable high GEM concentrations occur at night and low concentrations occur in the afternoon during PISM, which may be related to the nocturnal boundary layer structure. High values occurring in the late afternoon during the ISM may be related to long-range transport. Low concentrations of GEM observed during the morning in the ISM may originate from vegetation effects. The results of the trajectory model demonstrate that the sources of pollutants at Nyingchi are different with different circulation patterns. During westerly circulation in the PISM period, pollutants mainly originate from central India, northeastern India, and central Tibet. During the ISM period, the pollutants mainly originate from the southern part of the SET site. The strong precipitation and vegetation effects on Hg species during the ISM resulted in low Hg concentrations transmitted to Nyingchi during this period. Further, principal component analysis showed that long-distance transport, local emissions, meteorological factors, and snowmelt factors are the main factors affecting the local Hg concentration in Nyingchi. Long-distance transport factor dominates during PISM and ISM3, while local emissions is the major contributor between PISM and ISM3. Our results reveal the Hg species distribution and possible sources of the most important water vapor channel in the Tibetan Plateau and could serve as a basis for further transboundary transport flux calculations. |
| URI | http://hdl.handle.net/20.500.11897/638791 |
| ISSN | 1680-7316 |
| DOI | 10.5194/acp-22-2651-2022 |
| Indexed | SCI(E) |
| Appears in Collections: | 城市与环境学院 地表过程分析与模拟教育部重点实验室 |
