Distribution and air-sea exchange of mercury (Hg) in the Yellow Sea
Distribution and air-sea exchange of mercury (Hg) in the Yellow Sea
复制标题
黄海汞(Hg)分布及海气交换
DOI：
10.5194/acp-11-2881-2011
复制
发表时间：
2011-01-01
影响因子：
6.3
通讯作者：
Wang, S. W.
中科院分区：
文献类型：
--
作者：
Ci, Z. J.;Zhang, X. S.;Wang, S. W.
被中国东部和朝鲜半岛包围的黄海是东亚人为汞排放的潜在重要受体。然而，关于汞在该海洋系统中的分布和循环的文献很少。 2010年7月，科学三号航程在黄海航行期间，测量了大气中的气态元素汞（GEM或Hg(0)）、水中的总汞（THg）、活性汞（RHg）和溶解气态汞（DGM，主要是Hg(0)）。整个航程中GEM的平均（+/- SD）浓度为2.61 +/- 0.50 ng m(-3)（范围：1.68至4.34 ng m(-3)），普遍高于其他公海。 GEM的空间分布总体上呈现出明显的梯度，华东沿海附近浓度较高，开阔水域浓度较低，表明华东地区存在明显的大气汞外流。地表水中THg的平均浓度为1.69±0.35ng·l(-1)，RHg占THg的相当大比例(RHg：1.08±0.28ng·l(-1)，%RHg/THg=63.9%)。地表水中DGM的平均浓度为63.9+/-13.7pgl(-1)，始终表明地表水中Hg(0)相对于大气中Hg(0)处于过饱和状态(饱和度：7.8+/-2.3，范围为3.6-14.0)。根据两层交换模型，海气界面的平均 Hg(0) 通量估计为 18.3 +/- 11.8 ng m(-2) h(-1)。高风速和 DGM 水平导致极高的 Hg(0) 排放率。三个站的测量结果显示，水柱中 DGM、RHg 和 THg 没有明显的垂直模式。总体而言，与其他公海相比，黄海的汞含量较高，表明人类活动影响了东亚顺风的海洋汞循环。
The Yellow Sea, surrounded by East China and the Korea Peninsula, is a potentially important receptor for anthropogenic mercury (Hg) emissions from East Asia. However, there is little documentation about the distribution and cycle of Hg in this marine system. During the cruise covering the Yellow Sea in July 2010, gaseous elemental mercury (GEM or Hg(0)) in the atmosphere, total Hg (THg), reactive Hg (RHg) and dissolved gaseous mercury (DGM, largely Hg(0)) in the waters were measured aboard the R/V Kexue III. The mean (+/- SD) concentration of GEM over the entire cruise was 2.61 +/- 0.50 ng m(-3) (range: 1.68 to 4.34 ng m(-3)), which were generally higher than other open oceans. The spatial distribution of GEM generally reflected a clear gradient with high levels near the coast of East China and low levels in open waters, suggesting the significant atmospheric Hg outflow from East China. The mean concentration of THg in the surface waters was 1.69 +/- 0.35 ng l(-1) and the RHg accounted for a considerable fraction of THg (RHg: 1.08 +/- 0.28 ng l(-1), %RHg/THg = 63.9%). The mean concentration of DGM in the surface waters was 63.9 +/- 13.7 pg l(-1) and always suggested the supersaturation of Hg(0) in the surface waters with respect to Hg(0) in the atmosphere (the degree of saturation: 7.8 +/- 2.3 with a range of 3.6-14.0). The mean Hg(0) flux at the air-sea interface was estimated to be 18.3 +/- 11.8 ng m(-2) h(-1) based on a two-layer exchange model. The high wind speed and DGM levels induced the extremely high Hg(0) emission rates. Measurements at three stations showed no clear vertical patterns of DGM, RHg and THg in the water column. Overall, the elevated Hg levels in the Yellow Sea compared with other open oceans suggested that the human activity has influenced the oceanic Hg cycle downwind of East Asia.