Articles | Volume 17, issue 1
Atmos. Chem. Phys., 17, 627–643, 2017

Special issue: Global Mercury Observation System – Atmosphere...

Atmos. Chem. Phys., 17, 627–643, 2017

Research article 13 Jan 2017

Research article | 13 Jan 2017

Sensitivity model study of regional mercury dispersion in the atmosphere

Christian N. Gencarelli1, Johannes Bieser2,3, Francesco Carbone1, Francesco De Simone1, Ian M. Hedgecock1, Volker Matthias2, Oleg Travnikov4, Xin Yang5, and Nicola Pirrone6 Christian N. Gencarelli et al.
  • 1CNR-Institute of Atmospheric Pollution Research, Division of Rende, Rende, Italy
  • 2Institute of Coastal Research, Helmholtz-Zentrum Geesthacht, Geesthacht, Germany
  • 3National Aeronautics and Space Center (DLR), Oberpfaffenhofen, Weßling, Germany
  • 4Meteorological Synthesizing Centre, East of EMEP, 2nd Roshchinsky proezd, 8/5, 115419 Moscow, Russia
  • 5British Antarctic Survey, Cambridge, UK
  • 6CNR-Institute of Atmospheric Pollution Research, Monterotondo, Rome, Italy

Abstract. Atmospheric deposition is the most important pathway by which Hg reaches marine ecosystems, where it can be methylated and enter the base of food chain. The deposition, transport and chemical interactions of atmospheric Hg have been simulated over Europe for the year 2013 in the framework of the Global Mercury Observation System (GMOS) project, performing 14 different model sensitivity tests using two high-resolution three-dimensional chemical transport models (CTMs), varying the anthropogenic emission datasets, atmospheric Br input fields, Hg oxidation schemes and modelling domain boundary condition input. Sensitivity simulation results were compared with observations from 28 monitoring sites in Europe to assess model performance and particularly to analyse the influence of anthropogenic emission speciation and the Hg0(g) atmospheric oxidation mechanism. The contribution of anthropogenic Hg emissions, their speciation and vertical distribution are crucial to the simulated concentration and deposition fields, as is also the choice of Hg0(g) oxidation pathway. The areas most sensitive to changes in Hg emission speciation and the emission vertical distribution are those near major sources, but also the Aegean and the Black seas, the English Channel, the Skagerrak Strait and the northern German coast. Considerable influence was found also evident over the Mediterranean, the North Sea and Baltic Sea and some influence is seen over continental Europe, while this difference is least over the north-western part of the modelling domain, which includes the Norwegian Sea and Iceland. The Br oxidation pathway produces more HgII(g) in the lower model levels, but overall wet deposition is lower in comparison to the simulations which employ an O3 ∕ OH oxidation mechanism. The necessity to perform continuous measurements of speciated Hg and to investigate the local impacts of Hg emissions and deposition, as well as interactions dependent on land use and vegetation, forests, peat bogs, etc., is highlighted in this study.

Short summary
Atmospheric deposition is an important pathway by which Hg reaches marine ecosystems, where it can be methylated and enter the base of food chain. High resolution numerical experiments has been performed in order to investigate the contributions (sensitivity) of the Hg anthtropogenic emissions, speciation and atmospherical chemical reactions on Hg depositions over Europe. The comparison of wet deposition fluxes and concentrations measured on 28 monitioring sites were used to support the analysis.
Final-revised paper