Multi-year record of atmospheric mercury at Dumo d’Urville, East Antarctic coast: continental outflow and oceanic influences

Abstract. Under the framework of the Global Mercury Observation System (GMOS) project, a 3.5-year record of atmospheric gaseous elemental mercury (Hg(0)) has been gathered at Dumont d’Urville (DDU, 66°40’S, 140°01’E, 43 m above sea level) on the East Antarctic coast. Additionally, surface snow samples were collected in February 2009 during a traverse between Concordia Station located on the East Antarctic plateau and DDU. The record of atmospheric Hg(0) at DDU reveals particularities that are not seen at other coastal sites: a gradual decrease of concentrations over the course of winter, and a daily maximum concentration around midday in summer. Additionally, total mercury concentrations in surface snow samples were particularly elevated near DDU (up to 194.4 ng L−1) as compared to measurements at other coastal Antarctic sites. These differences can be explained by the more frequent arrival of inland air masses at DDU than at other coastal sites. This confirms the influence of processes observed on the Antarctic plateau on the cycle of atmospheric mercury at a continental scale, especially in areas subject to recurrent katabatic winds. DDU is also influenced by oceanic air masses and our data suggest that the ocean plays a dual role on Hg(0) concentrations. The open ocean may represent a source of atmospheric Hg(0) in summer whereas the sea-ice surface may provide reactive halogens in spring that can oxidize Hg(0).

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Multi-year record of atmospheric mercury at Dumont d'Urville, East Antarctic coast: continental outflow and oceanic influences

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-8265-2016 ◽

2016 ◽

Vol 16 (13) ◽

pp. 8265-8279 ◽

Cited By ~ 19

Author(s):

Hélène Angot ◽

Iris Dion ◽

Nicolas Vogel ◽

Michel Legrand ◽

Olivier Magand ◽

...

Keyword(s):

Elemental Mercury ◽

Atmospheric Mercury ◽

Observation System ◽

Daily Maximum ◽

Air Masses ◽

Gaseous Elemental Mercury ◽

Antarctic Plateau ◽

Continental Scale ◽

Surface Snow ◽

Snow Samples

Abstract. Under the framework of the Global Mercury Observation System (GMOS) project, a 3.5-year record of atmospheric gaseous elemental mercury (Hg(0)) has been gathered at Dumont d'Urville (DDU, 66°40′ S, 140°01′ E, 43 m above sea level) on the East Antarctic coast. Additionally, surface snow samples were collected in February 2009 during a traverse between Concordia Station located on the East Antarctic plateau and DDU. The record of atmospheric Hg(0) at DDU reveals particularities that are not seen at other coastal sites: a gradual decrease of concentrations over the course of winter, and a daily maximum concentration around midday in summer. Additionally, total mercury concentrations in surface snow samples were particularly elevated near DDU (up to 194.4 ng L−1) as compared to measurements at other coastal Antarctic sites. These differences can be explained by the more frequent arrival of inland air masses at DDU than at other coastal sites. This confirms the influence of processes observed on the Antarctic plateau on the cycle of atmospheric mercury at a continental scale, especially in areas subject to recurrent katabatic winds. DDU is also influenced by oceanic air masses and our data suggest that the ocean plays a dual role on Hg(0) concentrations. The open ocean may represent a source of atmospheric Hg(0) in summer whereas the sea-ice surface may provide reactive halogens in spring that can oxidize Hg(0). This paper also discusses implications for coastal Antarctic ecosystems and for the cycle of atmospheric mercury in high southern latitudes.

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Observation and analysis of speciated atmospheric mercury in Shangri-la, Tibetan Plateau, China

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-11041-2014 ◽

2014 ◽

Vol 14 (8) ◽

pp. 11041-11074 ◽

Cited By ~ 2

Author(s):

H. Zhang ◽

X. W. Fu ◽

C.-J. Lin ◽

X. Wang ◽

X. B. Feng

Keyword(s):

Tibetan Plateau ◽

Atmospheric Transport ◽

Seasonal Pattern ◽

Elemental Mercury ◽

Atmospheric Mercury ◽

North India ◽

Air Masses ◽

Gaseous Elemental Mercury ◽

Wet Scavenging ◽

In The Beginning

Abstract. This study reports the speciated concentration and the potential sources of atmospheric mercury measured at the Shangri-La Atmosphere Watch Regional Station (SAWRS), a pristine high-altitude site (3580 m a.s.l.) in Tibetan Plateau, China. The total gaseous mercury (TGM, defined as the sum of Gaseous Elemental Mercury, GEM, and gaseous oxidized mercury, GOM), GOM and particulate-bound mercury (PBM) were monitored from November 2009 to November 2010 to investigate the characteristics and atmospheric transport of mercury influenced by the Indian summer monsoon (ISM) and westerlies. The mean concentrations of TGM, PBM and GOM were 2.55 ± 0.73 ng m−3, 37.78 ± 31.35 pg m−3 and 7.90 ± 7.89 ng m−3. A notable seasonal pattern was observed with higher TGM concentrations in the beginning and end of the ISM. High TGM concentrations were associated with the transport of dry air that carried regional anthropogenic emissions from both domestic and foreign sources. The low PBM and GOM level was attributed to the deposition and wet scavenging during the ISM period. Backward trajectory analysis of air masses associated with TGM levels suggested that both the ISM and westerlies can carry Hg emitted in Burma, Bengal bay and north India to the SAWRS.

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New insights into the atmospheric mercury cycling in Central Antarctica and implications at a continental scale

10.5194/acp-2016-144 ◽

2016 ◽

Cited By ~ 1

Author(s):

Hélène Angot ◽

Olivier Magand ◽

Detlev Helmig ◽

Philippe Ricaud ◽

Boris Quennehen ◽

...

Keyword(s):

Chemical Exchange ◽

Ambient Air ◽

Oxidative Capacity ◽

Atmospheric Mercury ◽

Photochemical Reactions ◽

Heterogeneous Reactions ◽

Observation System ◽

Antarctic Plateau ◽

Continental Scale ◽

The Antarctic

Abstract. Under the framework of the GMOS project (Global Mercury Observation System) atmospheric mercury monitoring has been implemented at Concordia Station on the high-altitude Antarctic plateau (75°06’ S, 123°20’ E, 3220 m above sea level). We report here the first year-round measurements of gaseous elemental mercury (Hg(0)) in the atmosphere and in snowpack interstitial air on the East Antarctic ice sheet. This unique dataset shows evidence of a continuous oxidation of atmospheric Hg(0) in summer (24-hour daylight) due to the high oxidative capacity of the Antarctic plateau atmosphere at this period of the year. Summertime Hg(0) concentrations exhibited a pronounced daily cycle in ambient air with maximal concentrations around midday. Photochemical reactions and chemical exchange at the air/snow interface were prominent, highlighting the role of the snowpack on the atmospheric mercury cycle. Our observations reveal a 20 to 30 % decrease of atmospheric Hg(0) concentrations from May to mid-August (winter, 24-h darkness). This phenomenon has never been observed elsewhere and likely results from a gas-phase oxidation and/or heterogeneous reactions. We also reveal the occurrence of multi-day to weeklong atmospheric Hg(0) depletion events in summer, not associated with depletions of ozone, and likely due to a stagnation of air masses above the plateau triggering an accumulation of oxidants within the shallow boundary layer. Our observations suggest that the inland atmospheric reservoir is depleted in Hg(0) in summer. Due to katabatic winds flowing out from the Antarctic plateau down the steep vertical drops along the coast and according to observations at coastal Antarctic stations, the striking reactivity observed on the plateau most likely influences the cycle of atmospheric mercury at a continental scale.

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New insights into the atmospheric mercury cycling in central Antarctica and implications on a continental scale

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-8249-2016 ◽

2016 ◽

Vol 16 (13) ◽

pp. 8249-8264 ◽

Cited By ~ 19

Author(s):

Hélène Angot ◽

Olivier Magand ◽

Detlev Helmig ◽

Philippe Ricaud ◽

Boris Quennehen ◽

...

Keyword(s):

Chemical Exchange ◽

Ambient Air ◽

Oxidative Capacity ◽

Atmospheric Mercury ◽

Photochemical Reactions ◽

Observation System ◽

Data Set ◽

Antarctic Plateau ◽

Continental Scale ◽

The Antarctic

Abstract. Under the framework of the GMOS project (Global Mercury Observation System) atmospheric mercury monitoring has been implemented at Concordia Station on the high-altitude Antarctic plateau (75°06′ S, 123°20′ E, 3220 m above sea level). We report here the first year-round measurements of gaseous elemental mercury (Hg(0)) in the atmosphere and in snowpack interstitial air on the East Antarctic ice sheet. This unique data set shows evidence of an intense oxidation of atmospheric Hg(0) in summer (24-hour daylight) due to the high oxidative capacity of the Antarctic plateau atmosphere in this period of the year. Summertime Hg(0) concentrations exhibited a pronounced daily cycle in ambient air with maximal concentrations around midday. Photochemical reactions and chemical exchange at the air–snow interface were prominent, highlighting the role of the snowpack on the atmospheric mercury cycle. Our observations reveal a 20 to 30 % decrease of atmospheric Hg(0) concentrations from May to mid-August (winter, 24 h darkness). This phenomenon has not been reported elsewhere and possibly results from the dry deposition of Hg(0) onto the snowpack. We also reveal the occurrence of multi-day to weeklong atmospheric Hg(0) depletion events in summer, not associated with depletions of ozone, and likely due to a stagnation of air masses above the plateau triggering an accumulation of oxidants within the shallow boundary layer. Our observations suggest that the inland atmospheric reservoir is depleted in Hg(0) in summer. Due to katabatic winds flowing out from the Antarctic plateau down the steep vertical drops along the coast and according to observations at coastal Antarctic stations, the striking reactivity observed on the plateau most likely influences the cycle of atmospheric mercury on a continental scale.

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Airborne mercury species at the Råö background monitoring site in Sweden: distribution of mercury as an effect of long-range transport

Atmospheric Chemistry and Physics ◽

10.5194/acp-16-13379-2016 ◽

2016 ◽

Vol 16 (21) ◽

pp. 13379-13387 ◽

Cited By ~ 5

Author(s):

Ingvar Wängberg ◽

Michelle G. Nerentorp Mastromonaco ◽

John Munthe ◽

Katarina Gårdfeldt

Keyword(s):

Elemental Mercury ◽

Observation System ◽

Back Trajectory ◽

Mercury Species ◽

Monitoring Site ◽

Western Coast ◽

Air Masses ◽

Gaseous Elemental Mercury ◽

Back Trajectory Analysis ◽

Early Afternoon

Abstract. Within the EU-funded project, Global Mercury Observation System (GMOS) airborne mercury has been monitored at the background Råö measurement site on the western coast of Sweden from mid-May 2012 to the beginning of July 2013 and from the beginning of February 2014 to the end of May 2015. The following mercury species/fractions were measured: gaseous elemental mercury (GEM), particulate bound mercury (PBM) and gaseous oxidised mercury (GOM) using the Tekran measurement system. The mercury concentrations measured at the Råö site were found to be low in comparison to other, comparable, European measurement sites. A back-trajectory analysis to study the origin of air masses reaching the Råö site was performed. Due to the remote location of the Råö measurement station it receives background air about 60 % of the time. However, elevated mercury concentrations arriving with air masses coming from the south-east are noticeable. GEM and PBM concentrations show a clear annual variation with the highest values occurring during winter, whereas the highest concentrations of GOM were obtained in spring and summer. An evaluation of the diurnal pattern of GOM, with peak concentrations at midday or in the early afternoon, which often is observed at remote places, shows that it is likely to be driven by local meteorology in a similar way to ozone. Evidence that a significant part of the GOM measured at the Råö site has been formed in free tropospheric air is presented.

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Dynamic recycling of gaseous elemental mercury in the boundary layer of the Antarctic Plateau

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-12-18133-2012 ◽

2012 ◽

Vol 12 (7) ◽

pp. 18133-18161 ◽

Cited By ~ 3

Author(s):

A. Dommergue ◽

M. Barret ◽

J. Courteaud ◽

P. Cristofanelli ◽

C. P. Ferrari ◽

...

Keyword(s):

Mixing Layer ◽

Elemental Mercury ◽

Atmospheric Mercury ◽

Photochemical Reactions ◽

Solar Irradiation ◽

The Arctic ◽

Gaseous Elemental Mercury ◽

Antarctic Plateau ◽

Mixing Ratios ◽

The Antarctic

Abstract. Gaseous elemental mercury (Hg(0)) was investigated in the troposphere and in the interstitial air extracted from the snow at Dome Concordia station (alt. 3320 m) on the Antarctic Plateau during January 2009. Measurements showed evidence of a very dynamic and daily cycling of Hg(0) inside the mixing layer with a range of values from 0.2 ng m−3 up to 2.3 ng m−3. During low solar irradiation periods, fast Hg(0) oxidation processes in a confined layer were observed leading to an enrichment of the upper snow layers in divalent Hg. Unexpectedly high Hg(0) concentrations for such a remote place were measured under higher solar irradiation due to the reemission of Hg(0) by the snowpack via photochemical reactions. Hg(0) concentrations showed a negative correlation with ozone mixing ratios, which contrasts with atmospheric mercury depletion events observed during the Arctic spring. It remains unclear whether halogens are involved in Hg(0) oxidation. We suggest that snow surfaces may play a role in promoting the heterogeneous oxidation of Hg(0). The cycling of other oxidants should be investigated together with Hg in order to clarify the complex reactivity on the Antarctic Plateau.

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Speciated atmospheric mercury at Waliguan Global Atmospheric Watch station in the northeastern Tibetan Plateau: implication of dust related sources for particulate bound mercury

10.5194/acp-2021-290 ◽

2021 ◽

Author(s):

Hui Zhang ◽

Xuewu Fu ◽

Ben Yu ◽

Baoxin Li ◽

Peng Liu ◽

...

Keyword(s):

Tibetan Plateau ◽

Elemental Mercury ◽

Atmospheric Mercury ◽

Dust Particles ◽

Anthropogenic Emissions ◽

The Tibetan Plateau ◽

Mean Values ◽

Air Masses ◽

Gaseous Elemental Mercury ◽

Aerosol Index

Abstract. To understand the ambient levels and sources of atmospheric mercury (Hg) in the Tibetan Plateau, a full-year continuous measurement of speciated atmospheric mercury was conducted at Waliguan (WLG) Baseline Observatory (3816 m a.s.l.) from May 2012 to April 2013. Mean concentrations (±1 SD) of gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM) and particulate bound mercury (PBM) during the whole study period were 1.90 ± 0.80 ng m−3, 12.0 ± 10.6 pg m−3 and 65.4 ± 63.2 pg m−3, respectively. Seasonal variations of GEM were very small, while those of PBM were quite large with mean values being four times higher in cold (102.3 ± 66.7 pg m−3) than warm (22.8 ± 14.6 pg m−3) season. Anthropogenic emissions to the east of Tibetan Plateau contributed significantly to GEM pollution at WLG, while dust particles originated from desert and Gobi regions in Xinjiang province and Tibetan Plateau to the west of WLG were responsible to PBM pollution at WLG. This finding is also supported by the significant positive correlation between daily PBM concentration and daily cumulative absorbing aerosol index (AAI) encountered by air masses transported during the preceding two days.

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A 2 year record of atmospheric mercury species at a background Southern Hemisphere station on Amsterdam Island

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-14-14439-2014 ◽

2014 ◽

Vol 14 (10) ◽

pp. 14439-14470

Author(s):

H. Angot ◽

M. Barret ◽

O. Magand ◽

M. Ramonet ◽

A. Dommergue

Keyword(s):

Indian Ocean ◽

Southern Hemisphere ◽

Marine Boundary Layer ◽

Elemental Mercury ◽

Atmospheric Mercury ◽

Southern Indian Ocean ◽

Observation System ◽

Mercury Species ◽

Back Trajectories ◽

Gaseous Elemental Mercury

Abstract. Scarcity of mercury species records in the Southern Hemisphere is a critical weak point for the development of appropriate modeling and regulation scenarios. Under the framework of the "Global Mercury Observation System" (GMOS) project, a monitoring station has been set up on Amsterdam Island (37°48' S, 77°34' E) in the remote southern Indian Ocean. For the first time in the Southern Hemisphere, a 2 year record of gaseous elemental mercury (GEM), reactive gaseous mercury (RGM) and particle-bound mercury (PBM) is presented. GEM concentrations were remarkably steady (1.03 ± 0.08 pg m−3) while RGM and PBM concentrations were very low and exhibited a strong variability (mean: 0.34 pg m−3 [range: 0.28–4.07 pg m−3] and mean: 0.67 pg m−3 [range: 0.28–12.67 pg m−3], respectively). Despite the remoteness of the island, wind sector analysis, air mass back trajectories and the observation of radonic storms highlighted a long-range contribution from the southern African continent to the GEM and PBM budgets in winter during the biomass burning season. Lowest concentrations of GEM were associated with southerly polar and marine air masses from the remote southern Indian Ocean. This unique dataset provides new baseline GEM concentrations in the Southern Hemisphere mid-latitudes for further modeling studies, while mercury speciation along with upcoming wet deposition data will help improving our understanding of mercury cycle in the marine boundary layer.

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Global deposition of speciated atmospheric mercury to terrestrial surfaces: an overview

10.5194/acp-2019-347 ◽

2019 ◽

Author(s):

Lei Zhang ◽

Peisheng Zhou ◽

Shuzhen Cao ◽

Yu Zhao

Keyword(s):

Dry Deposition ◽

Urban Areas ◽

Wet Deposition ◽

Current Knowledge ◽

Elemental Mercury ◽

Atmospheric Mercury ◽

Future Research ◽

Observation System ◽

Mercury Deposition ◽

Gaseous Elemental Mercury

Abstract. One of the most important processes in the global mercury biogeochemical cycling is the deposition of atmospheric mercury, including gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM), and particulate-bound mercury (PBM), to terrestrial surfaces. In this paper, methods for the observation of wet, dry, litterfall, throughfall, and cloud/fog deposition and models for mercury dry deposition are reviewed. Surrogate surface methods with cation exchange membranes are widely used for GOM dry deposition measurements, while observation methods for GEM dry deposition are more diverse. The methodology for Hg wet deposition is more mature, but the influence of cloud/fog scavenging is easy to neglect. Dry deposition models for speciated mercury have high uncertainties owing to the presence of sensitive parameters related to GOM chemical forms. Observation networks for mercury wet deposition have been developed worldwide, with the Global Mercury Observation System (GMOS) covering the northern hemisphere, the tropics, and the southern hemisphere. Wet deposition implies the spatial distribution of atmospheric mercury pollution, while GOM dry deposition depends highly on the elevation. Litterfall Hg deposition is crucial to forests. Urban areas have high wet deposition and PBM dry deposition because of high reactive mercury levels. Grasslands and forests have significant GOM and GEM dry deposition, respectively. Evergreen broadleaf forests bear high litterfall Hg deposition. Future research needs have been proposed based on the current knowledge of global mercury deposition to terrestrial surfaces.

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Fluxes of gaseous elemental mercury (GEM) in the High Arctic during atmospheric mercury depletion events (AMDEs)

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-6923-2018 ◽

2018 ◽

Vol 18 (9) ◽

pp. 6923-6938 ◽

Cited By ~ 7

Author(s):

Jesper Kamp ◽

Henrik Skov ◽

Bjarne Jensen ◽

Lise Lotte Sørensen

Keyword(s):

Eddy Covariance ◽

Elemental Mercury ◽

Atmospheric Temperature ◽

High Arctic ◽

Atmospheric Mercury ◽

Research Station ◽

Co2 Fluxes ◽

Gaseous Elemental Mercury ◽

Surface Snow ◽

North Greenland

Abstract. Measurements of gaseous elemental mercury (GEM) fluxes over snow surfaces using a relaxed eddy accumulation (REA) system are carried out at the High Arctic site at the Villum Research Station, Station Nord, in North Greenland. Simultaneously, CO2 fluxes are determined using the eddy covariance (EC) technique. The REA system with dual inlets and dual analyzers is used to measure fluxes directly over the snow. The measurements were carried out from 23 April to 12 May during spring 2016, where atmospheric mercury depletion events (AMDEs) took place. The measurements showed a net emission of 8.9 ng m−2 min−1, with only a few minor episodes of net depositional fluxes, from a maximum deposition of 8.1 ng m−2 min−1 to a maximum emission of 179.2 ng m−2 min−1. The data support the theory that gaseous oxidized mercury (GOM) is deposited during AMDEs followed by formation of GEM on surface snow and is re-emitted as GEM shortly after the AMDEs. Furthermore, observation of the relation between GEM fluxes and atmospheric temperature suggests that GEM emission partly could be affected by surface heating. However, it is also clear that the GEM emissions are affected by many parameters.

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