The Antarctic Plateau snowpack is an important environment for the mercury geochemical cycle. We have extensively characterized and compared the changes in surface snow and atmospheric mercury concentrations that occur at Dome C. Three summer sampling campaigns were conducted between 2013 and 2016.

The three campaigns had different meteorological conditions that significantly affected mercury deposition processes and its abundance in surface snow. In the absence of snow deposition events, the surface mercury concentration remained stable with narrow oscillations, while an increase in precipitation results in a higher mercury variability. The Hg concentrations detected confirm that snowfall can act as a mercury atmospheric scavenger. A high temporal resolution sampling experiment showed that surface concentration changes are connected with the diurnal solar radiation cycle. Mercury in surface snow is highly dynamic and it could decrease by up to 90% within 4/6 h. A negative relationship between surface snow mercury and atmospheric concentrations has been detected suggesting a mutual dynamic exchange between these two environments.

Mercury concentrations were also compared with the Br concentrations in surface and deeper snow, results suggest that Br could have an active role in Hg deposition, particularly when air masses are from coastal areas.

This research presents new information on the presence of Hg in surface and deeper snow layers, improving our understanding of atmospheric Hg deposition to the snow surface and the possible role of re-emission on the atmospheric Hg concentration.

南极高原积雪是汞地球化学循环的重要环境。我们已广泛表征并比较了Dome C地面雪和大气汞浓度的变化.2013年至2016年进行了三个夏季采样活动。

这三个活动具有不同的气象条件，这些条件极大地影响了汞的沉积过程及其在表层雪中的丰度。在没有积雪事件的情况下，表面汞浓度在狭窄的振荡下保持稳定，而降水量的增加导致汞的可变性更高。检测到的汞浓度证实降雪可以充当汞大气清除剂。一个高时间分辨率的采样实验表明，表面浓度的变化与日太阳辐射周期有关。地表雪中的汞是高度动态的，在4/6小时内最多可减少90％。已检测到地表雪汞与大气浓度之间存在负相关关系，表明这两种环境之间存在相互动态交换。

还将汞浓度与地表和较深雪中的Br浓度进行了比较，结果表明Br可能在Hg沉积中起积极作用，尤其是当空气质量来自沿海地区时。

这项研究提供了有关表层和较深雪层中汞的存在的新信息，从而增进了我们对大气中汞在雪表面的沉积以及再排放对大气中汞浓度的可能作用的了解。