Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China.
Chemosphere. 2020 Oct;257:127151. doi: 10.1016/j.chemosphere.2020.127151. Epub 2020 May 24.
Spatial distributions of bromocarbons, including bromoform (CHBr), dibromochloromethane (CHBrCl), and dibromomethane (CHBr), and influential oceanographic parameters that determine their concentrations were measured in the marine atmosphere and seawater of the East China Sea (ECS) and western Pacific Ocean during two cruises from 14 to 24 September, 2017 and from 5 October to 3 December, 2018. The atmospheric concentrations of CHBr, CHBrCl, and CHBr were 0.33-3.02, 0.16-1.96, and 0.85-1.75 pptv over the western Pacific Ocean and 2.23-4.92, 0.26-1.52, and 0.24-7.47 pptv over the ECS, respectively. There was significant spatial variability in atmospheric bromocarbon concentrations in the study region, with higher concentration over the ECS. The atmospheric mixing ratios of bromocarbons were significantly correlated to the surface seawater bromocarbon concentrations and wind speed. In the ECS, input from terrestrial sources also significantly influenced the distributions of bromocarbons in air. PCA analysis revealed that seawater bromocarbon concentrations were correlated with both water mass and chlorophyll a. Generally lower CHBr/CHBr ratios were observed in the ECS, which was indicative of mixing and/or dilution in coastal areas. The estimated average sea-to-air fluxes of CHBrCl, CHBr, and CHBr were 46.86, -3.77, and -6.71 nmol m d in the western Pacific Ocean and 111.49, 0.89, and 321.74 nmol m d in the ECS, respectively. These results of the net sea-to-air fluxes indicated oceanic net uptake of CHBr and CHBr for the western Pacific Ocean and oceanic emission of bromocarbons for the ECS.
在 2017 年 9 月 14 日至 24 日和 2018 年 10 月 5 日至 12 月 3 日的两次航行中，测量了东中国海（ECS）和西太平洋海洋大气中的溴代碳氢化合物（包括溴仿（CHBr ）、二溴一氯甲烷（CHBrCl ）和二溴甲烷（CHBr ））的浓度及其分布，并确定了影响其浓度的海洋学参数。在西太平洋，大气中 CHBr 、CHBrCl 和 CHBr 的浓度分别为 0.33-3.02 、0.16-1.96 和 0.85-1.75 pptv ，而在 ECS 中则分别为 2.23-4.92 、0.26-1.52 和 0.24-7.47 pptv 。研究区域大气溴代碳浓度存在显著的空间变异性，ECS 地区浓度较高。溴代碳在大气中的混合比与表层海水溴代碳浓度和风速显著相关。在 ECS 中，陆地来源的输入也显著影响了空气中溴代碳的分布。主成分分析表明，海水溴代碳浓度与水体和叶绿素 a 均有关。通常在 ECS 中观察到较低的 CHBr/CHBr 比值，这表明在沿海地区存在混合和/或稀释。在西太平洋，CHBrCl 、CHBr 和 CHBr 的平均海气通量估计值分别为 46.86 、-3.77 和-6.71 nmol m d ，而在 ECS 中则分别为 111.49 、0.89 和 321.74 nmol m d 。这些净海气通量的结果表明，西太平洋海洋对 CHBr 和 CHBr 具有净吸收作用，而 ECS 海洋则排放溴代碳氢化合物。
