FATE OF MERCURY IN THE ARCTIC Michael Evan ... - COGCI

Fate of Mercury in the Arctic 30
accumulation. These samples will be preliminarily discussed since at the time of completion of this
PhD, research is still in progress.
3.2 Measurement of atmospheric elemental mercury and ozone
As seen from measurements in this work, and first reported by Shroeder et. al, 1998, the
destruction of ozone coincides with an atmospheric mercury depletion event. Therefore ozone
monitoring was an integral component of the campaigns investigating atmospheric mercury in the
Arctic, as is the measurement of total gaseous mercury, or gaseous elemental mercury.
The monitor used for atmospheric mercury measurements is the same analyser employed for on
site analysis of manual reactive gaseous mercury measurements, though there is also now, a fully
automated RGM monitor available, which combined with a particulate mercury unit and TGM
monitor, provide automated data of mercury fractionation. This type of unit will greatly improve the
effectiveness of future studies.
Ozone and GEM were measured at Station Nord, NE Greenland, until June 2002. On the Faroe
Islands, from May 2000 forward one year, and in Nuuk, Greenland from March 2002 and are still
ongoing. GEM was only measured at Station Nord from February until July each year.
3.3 Ozone measurements
Ground level ozone was measured using an UV absorption monitor, Monitorlab 8810, with a
detection limit of 1 ppbv and an uncertainty of 3 % for concentrations above 10 ppbv and 6 % for
concentrations below 10 ppbv, (all uncertainties are at a 95% confidence interval).
3.4 Gaseous elemental mercury measurements
Gaseous elemental mercury, GEM, was measured with high time resolution using an automated
dual channel, single amalgation, cold vapour atomic fluorescence spectroscopy (CVAFS) mercury
analyser, Tekran Analyser Model 2537 A, Tekran Inc., Toronto, Canada, following a standard
operating procedure (SOP) written by Alexandra Steffen and W. Schroeder, for use at the high