Elevated atmospheric mercury concentrations at the Russian polar station Amderma during Icelandic volcanoes' eruptions

Abstract. We estimate the long-range atmospheric transport of elemental mercury in the Northern Hemisphere and present new data for volcanic eruptions in Iceland. At the Polar station Amderma (Russia) of long-term observations of elemental mercury concentration (2009–2010), a change in the dynamics was recorded. For seasonal variability at the period from 2001–2009 negative trend (−0.66 ng per month) was fixed. However, the analysis of the last three years of measurement (2010–2012) showed the greatest positive trend (+0.97 ng per month). In April 2010 and the highest positive trend was observed (+0.24 ng m⁻³), for the first time for the whole (2001–2013). At the same time, high concentrations of gaseous elemental mercury in the range from 1.81 to 2.58 ng m⁻³ in Apr–Jun 2010 and from 1.81 to 3.31 ng m⁻³ in May–Jun 2011 in contrast to the typical concentrations of 1.51 ng m⁻³. During the period of 2010 and 2011 intensified volcanoes in Iceland and consequently volcanic eruptions in Iceland were considered the most probable cause of these increased concentrations. Until now, there have been no cases of recording a high concentration of mercury during the active eruption of the volcano, measured so far from the source of the eruption. In this way for the first time at the Amderma station in the Russian Arctic, high levels of elemental mercury were recorded as associated with the periods of active volcanoes Eyjafjallajokull (in 2010) and Grimsvotn (in 2011). The inverse trajectories calculated for a vertical profile covering a height of 500 and 3000 m above sea level the time level with high mercury concentrations confirmed that this was due to atmospheric transport from the northwest and was associated with the active Eyjafjallaicull and Grimsvotn volcanoes. Therefore, it can be assumed that these active volcanoes are the main sources of increased mercury concentrations in the northern hemisphere as a result of atmospheric transport of volcanic clouds to the monitoring point in the Russian Arctic.