Atmospheric Mercury Concentrations observed at ground-based monitoring sites globally distributed in the framework of the GMOS network

Abstract

<p><strong>Abstract.</strong> Long-term monitoring data of ambient mercury (Hg) on a global scale to assess its emission, transport, atmospheric chemistry, and deposition processes is vital to understanding the impact of Hg pollution on the environment. The Global Mercury Observation System (GMOS) project was funded by the European Commission (www.gmos.eu), and started in November 2010 with the overall goal to develop a coordinated global observing system to monitor Hg on a global scale, including a large network of ground-based monitoring stations, ad-hoc periodic oceanographic cruises and measurement flights in the lower and upper troposphere, as well as in the lower stratosphere. To date more than 40 ground-based monitoring sites constitute the global network covering many regions where little to no observational data were available before GMOS. This work presents atmospheric Hg concentrations recorded worldwide in the framework of the GMOS project (2010–2015), analyzing Hg measurement results in terms of temporal trends, seasonality and comparability within the network. Major findings highlighted in this paper include a clear gradient of Hg concentrations between the Northern and Southern Hemisphere, confirming that the gradient observed is mostly driven by local and regional sources, which can be anthropogenic, natural or a combination of both.</p>

Isotopic Composition of Gaseous Elemental Mercury in the Marine Boundary Layer of East China Sea

“…correlation slope = −1.42 ± 0.12‰/ng/m 3 ; and no significant relationship existed between GEM Δ 199 Hg and concentrations) and North America (no significant relationship existed between GEM δ 202 Hg, Δ 199 Hg, and GEM concentrations; Figure ). It should be noted that 70% of the GEM samples in North America and Europe had concentrations lower than the background values (1.53 ng/m 3 ) in the Northern Hemisphere (Sprovieri et al, ), whereas all the GEM samples at HNI had concentrations higher than the background in the North Hemisphere (Figure ). The sampling sites in North America and Europe were mostly located in the vegetation‐covered regions (e.g., forest and tundra) and/or free troposphere.…”

“…The potential source regions of elevated atmospheric GEM (>1.5 ng/m 3 ) observed at HNI are identified using a Potential Source Contribution Function (PSCF) approach (Fu, Marusczak, Heimburger, et al, ), based on the every 2‐hr calculations of seven‐day backward trajectories ending at HNI using the TrajStat Geographical Information System based software (Wang et al, ). The criterion of the elevated GEM (>1.5 ng/m 3 ) is when the concentration is greater than the background GEM concentrations in the Northern Hemisphere (Sprovieri et al, ). We also identified the potential source regions of low atmospheric GEM (<1.5 ng/m 3 ) at HNI using the PSCF approach.…”

Assessment of Regional Mercury Deposition and Emission Outflow in Mainland China

“…The total Hg emission quantity utilized in the base-case simulation is 1,561.2 Mg/year (848.0 Mg/year anthropogenic and 713.2 Mg/year natural) in the domain (Table 1). The boundary and initial conditions are regridded from the output of a global 3-D chemical transport model (GEOS-Chem) into the specification of study domain (Song et al, 2015). Other emission data, such as SO 2 , NO x , CO, and so forth, are obtained from Multiresolution Emission Inventory for China (M. Li et al, 2015) and regridded using ArcGIS 10.1 and National Center for Atmospheric Research Command Language.…”

“…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.…”

Chemical cycling and deposition of atmospheric mercury in polar regions: review of recent measurements and comparison with models

“…Deposition of mercury in the Arctic is typically inferred from concentrations of total mercury in the snowpack (e.g., Steffen et al, 2014) or from a Hg(0) flux gradient method Brooks et al, 2006;Cobbett et al, 2007;Steen et al, 2009) and not through direct measurement of wet and dry deposition, making it difficult to evaluate the accuracy of models predictions. To the best of our knowledge, NYA is the only site out of the four Arctic sites where wet deposition measurements have been reported (Sprovieri et al, 2016a). From May to December 2013, the observed net wet deposition flux is equal to 0.9 µg m −2 while modeled fluxes amount to 1.7, 3.2, 2.8, and 2.4 µg m −2 according to GLEMOS, GEOS-Chem, GEM-MACH-Hg, and ECH-MERIT, respectively.…”