The objectives of the project are: A) to determine temporal trends in atmospheric mercury concentrations and deposition processes of mercury in the Arctic, and to assist in the development of long-term strategies for this priority pollutant by: i) measuring ambient air Total Gaseous Mercury (TGM) concentrations in the Canadian Arctic (Alert) and investigating the linkage to elevated levels of mercury known to be present in the Arctic food chain; ii) investigating and establishing the causes of temporal variability (seasonal, annual) in mercury concentrations so that realistic representations (models) of atmospheric pathways and processes can be formulated, tested and validated; iii) studying the chemical and physical aspects of atmospheric mercury vapour transformation (oxidation) after polar sunrise and the resultant enhanced mercury deposition to the sea, snow and ice surfaces each year during springtime; and iv) obtaining a long-term time series of atmospheric mercury (TGM) concentrations at Alert for the purpose of establishing whether mercury in the troposphere of the northern hemisphere is (still) increasing and if so, at what rate; B) to establish a sound scientific basis for addressing existing gaps of knowledge of the behaviour of mercury in the Arctic environment that will enable international regulatory actions to reflect the appropriate environmental protection strategies and pollution controls for the Arctic by: i) studying the relative roles of anthropogenic and natural sources of mercury so as to clarify understanding of the atmospheric pathways leading to the availability of mercury to Arctic biota; ii) studying tropospheric TGM depletion mechanisms/processes leading to enhanced input of mercury to the Arctic biosphere in spring; iii) undertaking essential speciated measurements of particulate-phase and/or reactive gaseous-phase mercury as well as mercury in precipitation (snow/rain) to quantify wet and dry deposition fluxes into the Arctic environment; and vi) providing the scientific basis for the information and advice used in the preparation and development of Canadian international strategies and negotiating positions for appropriate international control objectives.
This project studies atmospheric processes, behaviour, characteristics and fate of mercury in cold climates.
- Alert, Nunavut, Canada (82.5 degrees N, 62.5 degrees W), 1995 to ongoing - continuous measurement of total gaseous mercury (TGM); - Alert, March to June 1997 and 1998 - extensive diagnostic experiments to confirm Arctic springtime depletion of mercury; sampled particulate-phase mercury intensively plus freshly-fallen snow; - Alert, Spring 2000 - Polar Sunrise/ALERT 2000 experiments studying mercury transformation, deposition, air-surface interaction and fate; - Alert, Winter and Spring 1999 - freshly-fallen snow; - Cooperation with other researchers is also generating TGM measurements at Point Barrow (Alaska, USA), Ny-Ålesund (Svalbard/Spitsbergen, Norway) and Amderma (Russia).
Continuous surface-level atmospheric TGM samples are collected and analyzed on-site by a Tekran mercury vapour analyzer (Schroeder et al. 1997, above). Snow and rain samples are to be analyzed for mercury at the National Water Research Institute, Canada Centre for Inland Waters, Burlington, ON, Canada. Wet deposition rates will be calculated from these data.
Quality control employed the QA/QC procedures of Canada's Northern Contaminants Program.
Close cooperation among researchers in the circumpolar nations has led to similar atmospheric mercury measurements in Alaska (USA), Greenland, Spitsbergen/Svalbard, Norway, Sweden, Finland and Russia. Please refer to the Canadian National AMAP Implementation Plan for details.
Department of Indian Affairs and Northern Development (DIAND/INAC)/ Northern Contaminants Program. Environment Canada, Canada's federal environmental agency.
"Mercury Measurement at Amderma, Russia" William Schroeder/Alexandra Steffen, Meteorological Service of Canada