Uncertainty Assessment of Gaseous Oxidized Mercury Measurements Collected by Atmospheric Mercury Network

2016 ◽  
Vol 51 (2) ◽  
pp. 855-862 ◽  
Author(s):  
Irene Cheng ◽  
Leiming Zhang
Keyword(s):  
Uncertainty Assessment ◽  
Atmospheric Mercury ◽  
Gaseous Oxidized Mercury

scholarly journals Dynamics of gaseous oxidized mercury at Villum Research Station during the High Arctic summer

2021 ◽  
Vol 21 (17) ◽  
pp. 13287-13309
Author(s):  
Jakob Boyd Pernov ◽  
Bjarne Jensen ◽  
Andreas Massling ◽  
Daniel Charles Thomas ◽  
Henrik Skov
Keyword(s):  
General Pattern ◽  
Ground Level ◽  
High Arctic ◽  
Atmospheric Mercury ◽  
The Arctic ◽  
Research Station ◽  
Cold Temperatures ◽  
Air Masses ◽  
Arctic Summer ◽  
Gaseous Oxidized Mercury

Abstract. While much research has been devoted to the subject of gaseous elemental mercury (GEM) and gaseous oxidized mercury (GOM) in the Arctic spring during atmospheric mercury depletion events, few studies have examined the behavior of GOM in the High Arctic summer. GOM, once deposited and incorporated into the ecosystem, can pose a threat to human and wildlife health, though there remain large uncertainties regarding the transformation, deposition, and assimilation of mercury into the food web. Therefore, to further our understanding of the dynamics of GOM in the High Arctic during the late summer, we performed measurements of GEM and GOM, along with meteorological parameters and atmospheric constituents, and utilized modeled air mass history during two summer campaigns in 2019 and 2020 at Villum Research Station (Villum) in northeastern Greenland. Seven events of enhanced GOM concentrations were identified and investigated in greater detail. In general, the common factors associated with event periods at ground level were higher levels of radiation and lower H2O mixing ratios, accumulated precipitation, and relative humidity (RH), although none were connected with cold temperatures. Non-event periods at ground level each displayed a different pattern in one or more parameters when compared to event periods. Generally, air masses during event periods for both campaigns were colder and drier, arrived from higher altitudes, and spent more time above the mixed layer and less time in a cloud compared to non-events, although some events deviated from this general pattern. Non-event air masses displayed a different pattern in one or more parameters when compared to event periods, although they were generally warmer and wetter and arrived from lower altitudes with little radiation. Coarse-mode aerosols were hypothesized to provide the heterogenous surface for halogen propagation during some of the events, while for others the source is unknown. While these general patterns were observed for event and non-event periods, analysis of individual events showed more specific origins. Five of the seven events were associated with air masses that experienced similar conditions: transported from the cold, dry, and sunlit free troposphere. However, two events experienced contrasting conditions, with air masses being warm and wet with surface layer contact under little radiation. Two episodes of extremely high levels of NCoarse and BC, which appear to originate from flaring emissions in Russia, did not contribute to enhanced GOM levels. This work aims to provide a better understanding of the dynamics of GOM during the High Arctic summer.

scholarly journals Dynamics of gaseous oxidized mercury at Villum Research Station during the High Arctic summer

2021 ◽  
Author(s):  
Jakob Boyd Pernov ◽  
Bjarne Jensen ◽  
Andreas Massling ◽  
Daniel Charles Thomas ◽  
Henrik Skov
Keyword(s):  
Meteorological Data ◽  
High Arctic ◽  
Atmospheric Mercury ◽  
The Arctic ◽  
Research Station ◽  
Cold Temperatures ◽  
Air Mass ◽  
Back Trajectories ◽  
Arctic Summer ◽  
Gaseous Oxidized Mercury

Abstract. While much research has been devoted to the subject of gaseous elemental mercury (GEM) and gaseous oxidized mercury (GOM) in the Arctic spring, during atmospheric mercury depletion events, few studies have examined the behavior of GOM in the High Arctic summer. GOM, once introduced into the ecosystem, can pose a threat to human and wildlife health, though there remain large uncertainties regarding the transformation, deposition, and assimilation of mercury into the ecosystem. Therefore, to further our understanding of the dynamics of gaseous oxidized mercury in the High Arctic during the late summer, we performed measurements of GEM and GOM along with meteorological parameters, atmospheric constituents, and air mass history during two summer campaigns in 2019 and 2020 at Villum Research Station (Villum) in Northeastern Greenland. Five events of enhanced GOM concentrations were identified and investigated in greater detail. The origin of these events was identified, through analysis of air mass back-trajectories, associated meteorological data, and other atmospheric constituents, to be the cold, dry free troposphere. These events were associated with low RH, limited precipitation, cold temperatures, and intense sunlight along the trajectory path. Events were positively correlated with ozone, aerosol particle number, and black carbon mass concentration, which were interpreted as an indication of tropospheric air masses. This work aims to provide a better understanding of the dynamics of GOM during the High Arctic summer.

scholarly journals Photoreduction of gaseous oxidized mercury changes global atmospheric mercury speciation, transport and deposition

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Alfonso Saiz-Lopez ◽  
Sebastian P. Sitkiewicz ◽  
Daniel Roca-Sanjuán ◽  
Josep M. Oliva-Enrich ◽  
Juan Z. Dávalos ◽  
...  
Keyword(s):  
Atmospheric Mercury ◽  
Mercury Speciation ◽  
Gaseous Oxidized Mercury

scholarly journals Validating an Evaporative Calibrator for Gaseous Oxidized Mercury

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2501
Author(s):  
Jan Gačnik ◽  
Igor Živković ◽  
Sergio Ribeiro Guevara ◽  
Radojko Jaćimović ◽  
Jože Kotnik ◽  
...  
Keyword(s):  
Computational Models ◽  
Metrological Traceability ◽  
Elemental Mercury ◽  
Atmospheric Mercury ◽  
Predictive Capability ◽  
Adsorption Enthalpy ◽  
Gas Concentration ◽  
Wide Range ◽  
Calibration Unit ◽  
Gaseous Oxidized Mercury

Understanding atmospheric mercury chemistry is the key for explaining the biogeochemical cycle of mercury and for improving the predictive capability of computational models. Increased efforts are being made to ensure comparable Hg speciation measurements in the air through establishing metrological traceability. While traceability for elemental mercury has been recently set, this is by no means the case for gaseous oxidized mercury (GOM). Since a calibration unit suitable for traceable GOM calibrations based on evaporation of HgCl2 solution was recently developed, the purpose of our work was to extensively evaluate its performance. A highly specific and sensitive 197Hg radiotracer was used for validation over a wide range of concentrations. By comparing experimental and calculated values, we obtained recoveries for the calibration unit. The average recoveries ranged from 88.5% for 1178 ng m−3 HgCl2 gas concentration to 39.4% for 5.90 ng m−3 HgCl2 gas concentration. The losses were due to the adsorption of oxidized Hg on the inner walls of the calibrator and tubing. An adsorption isotherm was applied to estimate adsorption enthalpy (ΔHads); a ΔHads value of −12.33 kJ mol−1 was obtained, suggesting exothermal adsorption. The results of the calibrator performance evaluation suggest that a newly developed calibration unit is only suitable for concentrations of HgCl2 higher than 1 µg m−3. The concentration dependence of recoveries prevents the system from being used for calibration of instruments for ambient GOM measurements. Moreover, the previously assessed uncertainty of this unit at µg m−3 level (2.0%, k = 2) was re-evaluated by including uncertainty related to recovery and was found to be 4.1%, k = 2. Calibrator performance was also evaluated for HgBr2 gas calibration; the recoveries were much lower for HgBr2 gas than for HgCl2 gas even at a high HgBr2 gas concentration (>1 µg m−3). As HgBr2 is often used as a proxy for various atmospheric HgBr species, the suitability of the unit for such calibration must be further developed.

GLOBAL IMPACT AND UNCERTAINTY ASSESSMENT OF SEA LEVEL RISE BASED ON MULTIPLE CLIMATE MODELS

2018 ◽  
Vol 74 (5) ◽  
pp. I_167-I_174 ◽  
Author(s):  
Koujiro TSUCHIDA ◽  
Makoto TAMURA ◽  
Naoko KUMANO ◽  
Eiji MASUNAGA ◽  
Hiromune YOKOKI
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Climate Models ◽  
Uncertainty Assessment ◽  
Global Impact
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