Air surface exchange of atmospheric mercury in Southern Canada during colder seasons

摘要

Total gaseous mercury (TGM) concentration and mercury flux measurements are conducted using a Tekran mercury analyzer and a flux chamber in Windsor (42 deg 18'N, 83 deg 01'W, average winter temperature -5 deg C), Ontario, Canada from Dec 2003 to March 2004. The measured ambient total gaseous mercury concentration had a mean value of 5.3 ng/m~3, higher than values observed in rural Canadian sites: this is likely due to the impact of local industries in Windsor area and transboundary pollutants from Detroit. MI. USA. The air-surface exchange flux had an average value of 2.6 ng/m~2/hr, and solar radiation had more profound effect on the mercury flux than air temperature. Diurnal variation of both TGM concentration and mercury flux were observed.