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

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, CO 2 fluxes are determined using the eddy covariance (EC)...

Full description

Bibliographic Details
Published in:Atmospheric Chemistry and Physics
Main Authors: Kamp, Jesper, Skov, Henrik, Jensen, Bjarne, Sørensen, Lise Lotte
Format: Text
Language:English
Published: 2019
Subjects:
Online Access:https://doi.org/10.5194/acp-18-6923-2018
https://www.atmos-chem-phys.net/18/6923/2018/
Description
Summary: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, CO 2 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.