Four years of continuous total gaseous mercury (TGM) measurements at sites in Ontario, Canada

Blanchard, Pierrette; Froude, F.; Martin, J.B.; Dryfhout-Clark, Helena; Woods, Jim

doi:10.1016/s1352-2310(02)00344-8

Cited by 52 publications

(41 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The minimum in the August -September period and maximum in the winter observed in the free troposphere are supported by the limited data from surface sites shown here and by a longer time series of data for these, and other, surface-based sites across Canada [Blanchard et al, 2002;Kellerhals et al, 2003;Poissant, 2000]. Kellerhals et al give the concentration of 1.60 ± 0.15 ng m À3 as representative of the median values seen at sites across Canada.…”

Section: Seasonalitysupporting

confidence: 74%

See 1 more Smart Citation

Vertical distribution of gaseous elemental mercury in Canada

Banic¹,

Beauchamp²,

Tordon³

et al. 2003

J. Geophys. Res.

View full text Add to dashboard Cite

[1] Measurements of gaseous elemental mercury (GEM) were made in three locations in Canada at altitudes from 0.1 to 7 km. In the summer in southeastern Canada, northwesterly winds bring air with a constant mixing ratio of GEM at altitudes up to 7 km, with a concentration near 1.5 nanograms per standard cubic meter of air (ng sm À3 ). In the winter in southern and central Ontario the mixing ratio is still approximately constant with altitude, but the concentration is 1.7 ng sm À3 . In the spring in the Arctic the concentration of gaseous elemental mercury at altitudes above 1 km is near 1.7 ng sm À3 ; however, there is evidence of episodic depletion of elemental mercury near the surface with mixing of depleted air to altitudes of 1 km. Measurements of GEM in cloud interstitial air and of mercury in cloud water indicate that the influence of a single cycling of air through cloud has little effect on the concentration of GEM. The GEM in air masses transported over the relatively unpopulated terrain of northern Canada during the summer indicates a lower limit of 5000 ng m À2 for an atmospheric column from the surface to 5 km. This gives a global burden of at least 2500 t for that altitude range. These data demonstrate the existence of a vast pool of mercury aloft, provide evidence for a long atmospheric lifetime, and illustrate the potential for long-range atmospheric transport of this metal at altitudes up to at least 7 km.

show abstract

Section: Seasonalitysupporting

confidence: 74%

“…The frequency distributions of the measurement data shown in Figure 8 for the surface sites at Egbert and Point Petre clearly show input of GEM from surface-based sources, as presented by Blanchard et al [2002]. At altitudes less than 1 km, the AS data show flights on which air depleted of GEM was sampled.…”

Section: Winter and Spring 1997-1998mentioning

confidence: 76%

Vertical distribution of gaseous elemental mercury in Canada

Banic¹,

Beauchamp²,

Tordon³

et al. 2003

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…There are several statistics that have been determined to assess whether the data set is suitable for PCA, such as the Kaiser-MeyerOlkin measure of sampling adequacy (> 0.6 criterion) and Bartlett's test of sphericity (p < 0.05 criterion). The number of components to retain is determined by other statistics such as Kaiser's criterion (eigenvalues > 1), scree plot, analysis of variance, and/or parallel analysis, as well as by achieving some minimal value of percent variance of the data set explained by all the components (e.g., 70-80 %) and how easily the components can be interpreted (Blanchard et al, 2002;Lynam and Keeler, 2006;Temme et al, 2007;Cheng et al, 2009). The number of components in a suitable solution to Eq.…”

Section: Principal Components Analysis (Pca) Descriptionmentioning

confidence: 99%

Overview of receptor-based source apportionment studies for speciated atmospheric mercury

Cheng

Zhang

2015

Atmos. Chem. Phys.

View full text Add to dashboard Cite

Abstract. Receptor-based source apportionment studies of speciated atmospheric mercury are not only concerned with source contributions but also with the influence of transport, transformation, and deposition processes on speciated atmospheric mercury concentrations at receptor locations. Previous studies applied multivariate receptor models including principal components analysis and positive matrix factorization, and back trajectory receptor models including potential source contribution function, gridded frequency distributions, and concentration-back trajectory models. Combustion sources (e.g., coal combustion, biomass burning, and vehicular, industrial and waste incineration emissions), crustal/soil dust, and chemical and physical processes, such as gaseous elemental mercury (GEM) oxidation reactions, boundary layer mixing, and GEM flux from surfaces were inferred from the multivariate studies, which were predominantly conducted at receptor sites in Canada and the US. Back trajectory receptor models revealed potential impacts of large industrial areas such as the Ohio River valley in the US and throughout China, metal smelters, mercury evasion from the ocean and the Great Lakes, and free troposphere transport on receptor measurements. Input data and model parameters specific to atmospheric mercury receptor models are summarized and model strengths and weaknesses are also discussed. Multivariate models are suitable for receptor locations with intensive air monitoring because they require long-term collocated and simultaneous measurements of speciated atmospheric Hg and ancillary pollutants. The multivariate models provide more insight about the types of Hg emission sources and Hg processes that could affect speciated atmospheric Hg at a receptor location, whereas back trajectory receptor models are mainly ideal for identifying potential regional Hg source locations impacting elevated Hg concentrations. Interpretation of the multivariate model output to sources can be subjective and challenging when speciated atmospheric Hg is not correlated with ancillary pollutants and when source emissions profiles and knowledge of Hg chemistry are incomplete. The majority of back trajectory receptor models have not accounted for Hg transformation and deposition processes and could not distinguish between upwind and downwind sources effectively. Ensemble trajectories should be generated to take into account the trajectory uncertainties where possible. One area of improvement that applies to all the receptor models reviewed in this study is the greater focus on evaluating the accuracy of the models at identifying potential speciated atmospheric mercury sources, source locations, and chemical and physical processes in the atmosphere. In addition to receptor model improvements, the data quality of speciated atmospheric Hg plays an equally important part in producing accurate receptor model results.

show abstract

“…An increasing number of studies have shown that biomass burning, industrial combustion, and ocean evaporation are three major emission sources of TGM in the regional scale (Blanchard et al, 2002;Fu et al, 2010;. Fig.…”

Section: Transportation Routes Of Tgmmentioning

confidence: 99%

“…Even though, GEM is the major species in the ambient atmosphere, which accounts for 95-99% of TAM with a residence time of 1.5-2.0 years in the atmosphere and can transport over great distances across continents (Schroeder and Munthe, 1998;Lin and Pehkonen, 1999;Fu et al, 2010;Jen et al, 2012). As such, long-range transportation and marine dissipation of mercury in the atmosphere has been identified as the predominant source at the background and the coastal regions (Ebinghaus et al, 1999;Blanchard et al, 2002;Sheu et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Field Measurement of Total Gaseous Mercury and Its Correlation with Meteorological Parameters and Criteria Air Pollutants at a Coastal Site of the Penghu Islands

Jen

Chen

Hung

et al. 2014

Aerosol Air Qual. Res.

View full text Add to dashboard Cite

This study investigated the seasonal and daily variations of the total gaseous mercury (TGM) concentration in the ambient atmosphere, the correlation of TGM concentration with meteorological parameters (e.g., temperature, humidity, and wind speed) and criteria air pollutant concentrations (e.g., SO 2 , NO x , CO, O 3 , PM 10 , and PM 2.5 ), as well as the transportation routes, at the Penghu Islands. The field measurement results showed that the average TGM concentration during the monitoring period was 3.17 ± 1.17 ng/m 3 , within the range of 1.17-8.63 ng/m 3 , with the highest concentration being observed in spring, while the TGM concentration typically increased in the morning, reached its peak concentration, and then started to decrease at nightfall. Moreover, the lowest average TGM concentration of 1.81 ± 0.15 ng/m 3 was observed in summer, and this figure is close to the background TGM concentration of the Northern Hemisphere (1.6-1.8 ng/m 3 ). The correlation analysis indicated that TGM concentration correlated positively with SO 2 , NO x , CO, O 3 , PM 10 , PM 2.5 and negatively with ambient temperature, relative humidity, and wind speed. In addition, the transportation route analysis showed that elevated TGM concentrations could be transported from either North China, East China, or South China to the Penghu Islands, while those originating from the South China Sea had the lowest contribution to the TGM levels at the Penghu Islands. Therefore, local sources and open burning might be mainly influenced by the long-range transportation of air masses, as the prevailing wind direction and air mass transportation routes potentially play critical roles in the variation of TGM concentration at the Penghu Islands.

show abstract

Four years of continuous total gaseous mercury (TGM) measurements at sites in Ontario, Canada

Cited by 52 publications

References 15 publications

Vertical distribution of gaseous elemental mercury in Canada

Vertical distribution of gaseous elemental mercury in Canada

Overview of receptor-based source apportionment studies for speciated atmospheric mercury

Field Measurement of Total Gaseous Mercury and Its Correlation with Meteorological Parameters and Criteria Air Pollutants at a Coastal Site of the Penghu Islands

Contact Info

Product

Resources

About