The objectives of this project are: A) to determine the pathway for the transfer of mercury in snowmelt to sea water during the melt period at Alert; B) to determine the extent of open water and wet ice in the summer Arctic as it affects the surface exchange of Hg using satellite radar imagery; and C) to determine the atmospheric dynamics associated with the photochemistry of mercury episodically during the polar sunrise period.
Heavy metal: mercury Other parameter groups: gas and heat transfer, melt process Other media: melt water
Acoustic sounder data (boundary layer height, degree of thermal and humidity variability, wind speed through layer) will be regularly archived at MSC/CCIW. In conjunction with other project team members, analyses will be conducted to correlate the atmospheric boundary layer structure to the surface concentrations of mercury, carbon dioxide and ozone. Water samples obtained using the Sampling Protocols will be shipped to CCIW where they will be further preserved by the addition of 0.1 M bromine monochloride (BrCl) to give a final concentration of 0.05 % BrCl on top of the 0.2 % HCl added in the field. The samples are allowed to sit at room temperature for approximately 1 week. The BrCl preservative is a very powerful oxidant and it has been well established that all forms of mercury (such as particulate, organic, and elemental) are converted to ionic Hg(2+) by this simple cold digestion BrCl procedure. Samples are then analyzed using a flow injection cold vapor atomic fluorescence spectrometric system. Approximately 40 mL aliquots of sample water are pumped into a continuous flow system incorporating acidified stannous chloride reduction which reduces the ionic Hg(2+) to elemental mercury which is then purged out of solution and detected by atomic fluorescence (Tekran 2500 CVAFS). The detection limit of the system, based on 3 x s.d. of 10 blanks, is 0.05 pg/mL. Calibration curves are generated before each sample run and standard reference materials are also run before and after samples to test the calibration curves and the drift characteristics of the analytical system. To assure high quality results and in addition to the in-house quality assurance outlined or implied above, the CCIW laboratory will be a participant in any relevant NCP interlab study. Various sources of SAR satellite imagery have been arranged: Radarsat and ERS-2 in conjunction with the C-ICE team and through the CIS. NASA Goddard expects, but cannot confirm immediately, that it will receive, process and forward appropriate microwave radiometer imagery and statistics of the Archipelago and Alert areas during the melt process. Image processing involving the determination of relative extent of open water and wet surface will be carried out at MSC/CCIW.
As part of Canada's Northern Contaminants Program (NCP), the laboratories at CCIW participate in the NCP QA/AC program. QA/QC procedures are detailed above with methods.
- Department of Indian Affairs and Northern Development, Northern Contaminants Program; - Environment Canada, Canada's federal environmental agency
"Mercury Measurements at Alert" Bill Schroeder, Meteorological Service of Canada