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

Fate of Mercury in the Arctic 29
Atmospheric mercury and ozone measurements were made by the NERI team at two sites in
Greenland: Station Nord and Nuuk, and on the Faroe Islands, in Thorshavn; and by the
ORNL/NOAA/US EPA team at Barrow, Alaska.
Manual measurements of reactive gaseous mercury and experiments were performed at Oak
Ridge National Laboratory, Environmental Sciences Division, and at Walker Branch Research
Station, US National Oceanic and Atmospheric Administration, NOAA, Atmospheric Turbulence
and Diffusion Division, ATDD, Oak Ridge, USA. RGM measurements in the spring, 2001
campaign in Barrow Alaska, were performed by the US team.
The relaxed eddy accumulation system was developed at NERI, with trial and developmental
experiments carried out in Oak Ridge. The system was deployed for the first ever measurements of
RGM flux in the Arctic at the Barrow Arctic Mercury Study site, during the spring of 2001, with
following deployments for developmental purposes only, at Walker Branch in Oak Ridge, as well as
Lille Valby, a NERI experimental site, at an agricultural field north of Roskilde, Denmark. The
improved NOAA relaxed eddy accumulation system was deployed at Lille Valby to compare with
the initial REA system, and for the Spring 2002, Station Nord campaign. The Station Nord
campaign deployed the first NERI system as well, as a back up.
Peat cores were collected from a fen located in southern Greenland, a raised bog in Denmark, a
blanket bog on the Faroe Islands, and two Arctic island locations: on Bathurst Island, Canada and
on Nordvestø, Carey Islands, Greenland, located between the northwest corer of Greenland and
Ellesmere Island, Canada. Samples from Bathurst Island and continental Canada and the USA were
given to another student, Nicolas Givelet, Berne, for primary investigation, and will not be
discussed in this thesis. Samples from Nordvestø are unique in that they are from peat that is
guarnogenic, i.e., nourished by sea bird droppings, as they sit on the island cliffs looking for prey.
They therefore have the potential of providing a primarily biogenic Holocene record of mercury