Elemental mercury in the atmospheric boundary layer of the Atlantic Ocean during Polarstern cruise ANT-XXV/5

During Polarstern cruise ANT-XXV/5 in April/May 2009, the marine atmosphere was sampled via PTFE (Polytetrafluorethylen) tubing extending from the front of the upper deck to labs on the main deck of r/v Polarstern and then analyzed for elemental mercury in air (Hg0-air) using the same Tekran 2537A as for Hg0-water measurements. The time interval of Hg0-air measurements was 5-min with gaps of about 20 min each hour because of intermittent Hg0-water measurements. The data were checked for potential contamination during tailwind situations (relative wind speed and direction) and doubtful values were removed. The detection limit was 0.1 ng L-1 (on ANT-XXV/5: 5 times the Hg0-air values were below the detection limit).

2009年4月至5月期间，在“极地号”（r/v Polarstern）科考航次ANT-XXV/5中，研究人员通过聚四氟乙烯（PTFE，Polytetrafluorethylen）管路采集海洋大气样品：该管路从该科考船上层甲板前部延伸至主甲板实验室，随后采用与水体单质汞（Hg0-water）检测同款的Tekran 2537A分析仪，对空气中的单质汞（Hg0-air）开展分析检测。空气中单质汞的检测间隔为5分钟，每小时约存在20分钟的检测间隙，原因是需间歇性开展水体单质汞检测工作。研究人员针对顺风工况（结合相对风速与风向）下可能存在的样品污染情况进行了核查，并剔除了存疑的检测数据。该方法的检出限为0.1 ng·L⁻¹，在ANT-XXV/5航次中，共有5组空气中单质汞浓度值低于该检出限。