Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, No. 18 Shuangqing Road, Beijing 100085, China; Graduate School of Chinese Academy of Sciences, Beijing 100049, China.
Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, No. 18 Shuangqing Road, Beijing 100085, China.
Environ Pollut. 2016 May;212:535-543. doi: 10.1016/j.envpol.2016.03.016. Epub 2016 Mar 11.
Two oceanographic cruises were carried out in the East China Sea (ECS) during the summer and fall of 2013. The main objectives of this study are to identify the spatial-temporal distributions of gaseous elemental mercury (GEM) in air and dissolved gaseous mercury (DGM) in surface seawater, and then to estimate the Hg(0) flux. The GEM concentration was lower in summer (1.61 ± 0.32 ng m(-3)) than in fall (2.20 ± 0.58 ng m(-3)). The back-trajectory analysis revealed that the air masses with high GEM levels during fall largely originated from the land, while the air masses with low GEM levels during summer primarily originated from ocean. The spatial distribution patterns of total Hg (THg), fluorescence, and turbidity were consistent with the pattern of DGM with high levels in the nearshore area and low levels in the open sea. Additionally, the levels of percentage of DGM to THg (%DGM) were higher in the open sea than in the nearshore area, which was consistent with the previous studies. The THg concentration in fall was higher (1.47 ± 0.51 ng l(-1)) than those of other open oceans. The DGM concentration (60.1 ± 17.6 pg l(-1)) and Hg(0) flux (4.6 ± 3.6 ng m(-2) h(-1)) in summer were higher than those in fall (DGM: 49.6 ± 12.5 pg l(-1) and Hg(0) flux: 3.6 ± 2.8 ng m(-2) h(-1)). The emission flux of Hg(0) from the ECS was estimated to be 27.6 tons yr(-1), accounting for ∼0.98% of the global Hg oceanic evasion though the ECS only accounts for ∼0.21% of global ocean area, indicating that the ECS plays an important role in the oceanic Hg cycle.
2013 年夏秋季在中国东海（ECS）进行了两次海洋学考察。本研究的主要目的是确定空气中气态元素汞（GEM）和表层海水中溶解态气态汞（DGM）的时空分布，然后估算 Hg(0)通量。夏季 GEM 浓度较低（1.61±0.32ngm-3），秋季较高（2.20±0.58ngm-3）。轨迹分析表明，秋季高气态汞水平的气团主要来源于陆地，而夏季高气态汞水平的气团主要来源于海洋。总汞（THg）、荧光和浊度的空间分布模式与近岸地区 DGM 水平较高、开阔海域 DGM 水平较低的模式一致。此外，开阔海域 DGM 与 THg 的比值（%DGM）高于近岸海域，这与以往的研究一致。秋季 THg 浓度较高（1.47±0.51ngl-1），高于其他开阔海域。夏季 DGM 浓度（60.1±17.6pgl-1）和 Hg(0)通量（4.6±3.6ngm-2h-1）高于秋季（DGM：49.6±12.5pgl-1，Hg(0)通量：3.6±2.8ngm-2h-1）。估算东海 Hg(0)的排放通量为 27.6 吨 yr-1，占全球海洋 Hg 逸出量的 0.98%，尽管东海仅占全球海洋面积的 0.21%，这表明东海在海洋 Hg 循环中起着重要作用。
