1Independent researcher, 3031 Cedar Avenue, Montreal, QC, H3Y 1Y8, Canada
2Air Quality Research Division, Environment Canada, 2121 TransCanada Highway, Dorval, QC, H9P 1J3, Canada
3Norwegian Univ. of Science and Technology, Høgskoleringen 5, 7491 Trondheim, Norway
4Independent researcher, 811-4998 Maisonneuve West, Westmount, QC, H3Z 1N2, Canada
5Norwegian Meteorological Institute, Allegt. 70, 5007 Bergen, Norway
6Norwegian Institute for Air Research, P.O. Box 100, 2027 Kjeller, Norway
7Science and Technology Branch, Environment Canada, 4905 Dufferin St., Toronto, ON, M3H 5T4, Canada
Abstract. A portion of the highly toxic methylmercury that bioaccumulates in aquatic life is created from mercury entering bodies of water with snowpack meltwater. To determine the importance of meltwater as a source of aquatic mercury, it is necessary to understand the environmental processes that govern the behavior of snowpack-related mercury. In this study we investigate relationships among 5 types of snowpack-related mercury observations and 20 model environmental variables. The observation types are the 24-h fractional loss of mercury from surface snow, and the concentrations of mercury in surface snow, seasonal snowpacks, the snowpack meltwater's ionic pulse, and long-term snowpack-related records. The model environmental variables include those related to atmospheric mercury, insolation, wind, atmospheric stability, snowpack physical characteristics, atmospheric pressure, and solid precipitation. Correlation coefficients and multiple linear regressions were calculated twice: once with all observations, and once with observations from locations presumably affected by oxidizing and stabilizing snowpack-related halogens excluded. We find that the presence of snowpack-related halogens has a significant impact on the behavior of snowpack-related mercury. Physically, snowpack-related mercury observations are most strongly controlled by the dry and wet depositions of oxidized mercury. The burial of mercury by fresh snowfalls and the wind driven ventilation of snowpacks are important processes. Indeed, in the absence of snowpack-related halogens, the 24-h fractional loss of mercury from surface snow is fully controlled by mercury deposition and surface-level atmospheric wind speed, stability, and surface pressure. The concentration of mercury in long-term records is affected by latitude, ventilation and surface pressure.