Atmospheric mercury terrestrial background site, South-Eastern Australia Data
Description
Understanding of Southern Hemisphere atmospheric mercury (Hg) is vastly underrepresented in the current global understanding of seasonal variation and drivers of Hg, particularly over terrestrial environments. Relationships have been observed between atmospheric Hg and air temperature, solar radiation, relative humidity, wind speed, and direction and meso and macro scale atmospheric circulation, but these drivers are largely unexplored in the Southern Hemisphere. This study provides 14 months of atmospheric Total Gaseous Mercury (TGM) and Reactive Mercury (RM) measurements undertaken at an Australian terrestrial background site to determine seasonal variation and its potential drivers. 5-minute continuous TGM concentrations were measured by Tekran 2537B and then aggerated to hourly concentrations. Measurements of RM were undertaken concurrently using the University of Nevada-Reno Reactive Mercury Active System at 2-week frequencies. Study average GEM concentrations were 0.68 ng m-3 (±0.22 ng m-3). Highest hourly TGM concentrations occurred during austral summer and lowest in austral winter (0.88 and 0.43 ng m-3, respectively). RM 2-weekly concentrations over the study average 2.41 pg m-3 (±1.68 pg m-3), peaking in summer (3.43 pg m-3) and were lowest in winter (1.93 pg m-3). Summer and spring Hg concentrations were influenced by northeasterly air masses passing through the Sydney urban region, with more efficient gaseous oxidation during these seasons. In winter, concentrations were mainly driven by inland transport of mercury from ocean evasion. Overall, seasonal Hg variability at this site was largely controlled by shifts in prevailing air mass transport. Data included: hourly TGM measurements between April 2017 and June 2018, with relevant Environmental variables; 2weekly Reactive Mercury measurements, TGM and Environmental Variables averaged to 2week values.
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Institutions
- University of TorontoOntario, Toronto