Atmospheric speciated mercury concentrations on an island between China and  Korea: sources and transport pathways

Lee, Gang-San; Kim, Pyung-Rae; Han, Yong; Holsen, Thomas M.; Seo, Yong Seok; Yi, Seung‐Muk

doi:10.5194/acp-16-4119-2016

Cited by 33 publications

(8 citation statements)

References 74 publications

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“…The mean concentrations (±1σ) of GEM, GOM, and PBM 2.5 during the entire observation period from the year 2007 to 2018 were 1.81 ± 0.43 ng m −3 (hourly mean values for 5 min intervals, N = 53,840), 1.7 ± 2.9 pg m −3 (N = 22,071) and 2.6 ± 3.6 pg m −3 (N = 22,058), respectively (Table 1). The mean GEM concentrations were lower than those reported for urban, suburban, and remote sites in the East Asian region [15,[42][43][44][45], but were slightly higher than the background concentrations recorded in the Northern hemisphere (1.3-1.6 ng m −3 ) and in the Southern hemisphere (around 1.0 ng m −3 ) [14,46]. Thus, it was inferred that the concentrations of Hg at Cape Hedo were elevated due to regional pollution because there are no local Hg stationary emission sources around this site.…”

Section: Concentrations Of Gem Gom and Pbm 25contrasting

confidence: 59%

Long-Term Observation of Atmospheric Speciated Mercury during 2007–2018 at Cape Hedo, Okinawa, Japan

et al. 2019

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The concentrations of atmospheric gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particle-bound mercury (particles with diameter smaller than 2.5 μm; PBM2.5) were continuously observed for a period of over 10 years at Cape Hedo, located on the north edge of Okinawa Island on the border of the East China Sea and the Pacific Ocean. Regional or global scale mercury (Hg) pollution affects their concentrations because no local stationary emission sources of Hg exist near the observation site. Their concentrations were lower than those at urban and suburban cities, as well as remote sites in East Asia, but were slightly higher than the background concentrations in the Northern Hemisphere. The GEM concentrations exhibited no diurnal variations and only weak seasonal variations, whereby concentrations were lower in the summer (June–August). An annual decreasing trend for GEM concentrations was observed between 2008 and 2018 at a rate of −0.0382 ± 0.0065 ng m−3 year−1 (−2.1% ± 0.36% year−1) that was the same as those in Europe and North America. Seasonal trend analysis based on daily median data at Cape Hedo showed significantly decreasing trends for all months. However, weaker decreasing trends were observed during the cold season from January to May, when air masses are easily transported from the Asian continent by westerlies and northwestern monsoons. Some GEM, GOM, and PBM2.5 pollution events were observed more frequently during the cold season. Back trajectory analysis showed that almost all these events occurred due to the substances transported from the Asian continent. These facts suggested that the decreasing trend observed at Cape Hedo was influenced by the global decreasing GEM trend, but the rates during the cold season were restrained by regional Asian outflows. On the other hand, GOM concentrations were moderately controlled by photochemical production in summer. Moreover, both GOM and PBM2.5 concentrations largely varied during the cold season due to the influence of regional transport rather than the trend of atmospheric Hg on a global scale.

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Section: Concentrations Of Gem Gom and Pbm 25contrasting

confidence: 59%

Long-Term Observation of Atmospheric Speciated Mercury during 2007–2018 at Cape Hedo, Okinawa, Japan

et al. 2019

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“…Another obvious feature was that the amplitude of the RGM concentration was much greater than the GEM, and this further indicated that the RGM was easily removed from the atmosphere through both the wet and dry deposition. In addition, we found that the RGM concentrations in the nearshore area were not always higher than those in the open sea, except for the measurements in the PRE, suggesting that the RGM in the remote marine atmosphere presumably did not originate from land but from the in situ photo-oxidation of Hg 0 , which had been reported in previous studies (e.g., Hedgecock and Pirrone, 2001;Lindberg et al, 2002;Laurier et al, 2003;Sprovieri et al, 2003Sprovieri et al, , 2010Sheu and Mason, 2004;Laurier and Mason, 2007;Soerensen et al, 2010a;Wang et al, 2015).…”

Section: Spatial Distributions Of Gem and Rgmsupporting

confidence: 63%

Speciated atmospheric mercury and sea–air exchange of gaseous mercury in the South China Sea

Wang

Fan

et al. 2019

Atmos. Chem. Phys.

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The characteristics of the reactive gaseous mercury (RGM) and particulate mercury (Hg P ) in the marine boundary layer (MBL) are poorly understood, due in part to sparse data from the sea and ocean. Gaseous elemental Hg (GEM), RGM, and size-fractionated Hg P in the marine atmosphere, and dissolved gaseous Hg (DGM) in surface seawater, were determined in the South China Sea (SCS) during an oceanographic expedition (3-28 September 2015). The mean concentrations of GEM, RGM, and Hg P 2.5 were 1.52 ± 0.32 ng m −3 , 6.1 ± 5.8 pg m −3 , and 3.2 ± 1.8 pg m −3 , respectively. A low GEM level indicated that the SCS suffered less influence from fresh emissions, which could be due to the majority of air masses coming from the open oceans, as modeled by back trajectories. Atmospheric reactive Hg (RGM + Hg P 2.5 ) represented less than 1 % of total atmospheric Hg, indicating that atmospheric Hg existed mainly as GEM in the MBL. The GEM and RGM concentrations in the northern SCS (1.73 ± 0.40 ng m −3 and 7.1 ± 1.4 pg m −3 , respectively) were significantly higher than those in the western SCS (1.41 ± 0.26 ng m −3 and 3.8 ± 0.7 pg m −3 ), and the Hg P 2.5 and Hg P 10 levels (8.3 and 24.4 pg m −3 ) in the Pearl River estuary (PRE) were 0.5-6.0 times higher than those in the open waters of the SCS, suggesting that the PRE was polluted to some extent. The size distribution of Hg P in PM 10 was observed to be three-modal, with peaks around < 0.4, 0.7-1.1, and 5.8-9.0 µm, respectively, but the coarse modal was the dominant size, especially in the open SCS. There was no significant diurnal pattern of GEM and Hg P 2.5 , but we found that the mean RGM concentration was significantly higher in daytime (8.0 ± 5.5 pg m −3 ) than in nighttime (2.2 ± 2.7 pg m −3 ), mainly due to the influence of solar radiation. In the northern SCS, the DGM concentrations in the nearshore area (40-55 pg L −1 ) were about twice as high as those in the open sea, but this pattern was not significant in the western SCS. The sea-air exchange fluxes of Hg 0 in the SCS varied from 0.40 to 12.71 ng m −2 h −1 with a mean value of 4.99 ± 3.32 ng m −2 h −1 . The annual emission flux of Hg 0 from the SCS to the atmosphere was estimated to be 159.6 t yr −1 , accounting for about 5.54 % of the global Hg 0 oceanic evasion, although the SCS only represents 1.0 % of the global ocean area. Additionally, the annual dry deposition flux of atmospheric reactive Hg represented more than 18 % of the annual evasion flux of Hg 0 , and therefore the dry deposition of atmospheric reactive Hg was an important pathway for the input of atmospheric Hg to the SCS.

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“…Han et al, ; Y.‐J. Han et al, ; Hong et al, ; Huang, Kang, Zhang, et al, ; Huang et al, , ; Lee et al, ; Ma et al, ; Ma, Wang, Du, et al, ; Ma, Wang, Sun, et al, ; Sheu & Lin, , ; Sheu et al, , ; Song et al, ; Tang et al, ; Y. M. Wang, Peng, et al, ; Weiss‐Penzias et al, ; Xu et al, , ). GEM = gaseous elemental mercury; GOM = gaseous oxidized mercury; PBM = particulate bound mercury.…”

Section: Resultsmentioning

confidence: 99%

“…Chen et al, 2016;Ci et al, 2015;Ci, Zhang, & Wang, 2011, Ci et al, 2012Ci, Zhang, Wang, & Niu, 2011aFriedli et al, 2011;Fu, Feng, Dong, et al, 2010;Fu, Feng, Liang, et al, 2012;Fu, Feng, Shang, et al, 2012;Fu et al, 2011;Fu, Feng, Sommar, et al, 2012;Fu, Zhu, et al, 2016;Fu, Zhang, Yu, et al, 2015;Y.-J. Han et al, 2014;Hong et al, 2016;Huang et al, 2013Huang et al, , 2015Lee et al, 2016;Ma et al, 2016;Sheu & Lin, 2011Sheu et al, , 2010Song et al, 2015;Tang et al, 2018; Y. M. Wang, Peng, et al, 2014;Weiss-Penzias et al, 2015;Xu et al, 2013Xu et al, , 2015. GEM = gaseous elemental mercury; GOM = gaseous oxidized mercury; PBM = particulate bound mercury.…”

Section: Evaluation Of Model Performance Using Base-case Simulation Rmentioning

confidence: 99%

Assessment of Regional Mercury Deposition and Emission Outflow in Mainland China

et al. 2018

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Mainland China is the largest emission region of anthropogenic mercury (Hg) in the world. There have been concerns regarding the emission outflow and chemical transport budget of Hg in the region. Earlier assessments of Hg chemical transport were based on relatively outdated emission data. Recent estimates for anthropogenic (Wu et al., 2016, https://doi.org/10.1021/acs.est.6b04308) and natural Hg emissions (X. Wang, Lin, et al., 2016, https://doi.org/10.5194/acp-16-11125-2016) show substantial differences from earlier emission inventories. In this study, we applied the updated Hg emission estimates to reassess the regional transport budget using Community Multiscale Air Quality‐Hg v5.1. Our results show that the variation of simulated concentration, deposition, and associated emission outflow of Hg are primarily influenced by the spatial‐temporal variation of Hg emissions, monsoon shifts, and particulate matter pollution in China. Total Hg deposition in Mainland China is estimated to be 422 Mg/year, and approximately two thirds of the deposition is contributed by domestic emissions. The net Hg transport budget from Mainland China is 511 Mg/year, contributing to 10% of Hg deposition in other regions of the world. This reassessment points to a ~25% reduction in total annual outflow compared to the previous estimate by Lin et al. (2010, https://doi.org/10.5194/acp-10-1853-2010). Such reduction is mainly caused by changes in Hg emission quantity, speciation, and spatial/temporal distributions. More modeling studies focusing on reducing uncertainties of emission inventories and Hg atmospheric chemistry are needed for continuous assessment of Hg emission outflow in this emission‐intensive region.

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Atmospheric speciated mercury concentrations on an island between China and Korea: sources and transport pathways

Cited by 33 publications

References 74 publications

Long-Term Observation of Atmospheric Speciated Mercury during 2007–2018 at Cape Hedo, Okinawa, Japan

Long-Term Observation of Atmospheric Speciated Mercury during 2007–2018 at Cape Hedo, Okinawa, Japan

Speciated atmospheric mercury and sea–air exchange of gaseous mercury in the South China Sea

Assessment of Regional Mercury Deposition and Emission Outflow in Mainland China

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