Non-local drivers of the summer hypoxia in the East China Sea off the Changjiang Estuary
Non-local drivers of the summer hypoxia in the East China Sea off the Changjiang Estuary
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夏季长江口东海缺氧的非本地驱动因素
DOI：
10.1016/j.ecss.2016.08.032
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发表时间：
2017-11
期刊：
影响因子：
--
通讯作者：
Wang L.F.
中科院分区：
文献类型：
--
作者：
Liu J.W.;Wang H.J.;Guo L.G.;Wang L.F.
长江口附近的东海位于长江羽流近场附近，是表层水体浮游植物水华和次表层/底层沃茨水体缺氧的热点地区。基于2009年和2011年夏季的野外观测资料，研究了长江口东海夏季低氧发展的非本地驱动因子，并分析了初始溶解氧（DO）水平对夏季低氧发展的影响。在24.2 < σθ< 25.2的等密度线上，底层水团可以追溯到吕宋海峡上游约1300 km处，在那里黑潮次表层水（水深约220 m，溶解氧含量约190 μmol kg−1）与南海次表层水（水深约120 m，溶解氧含量约130 μmol kg−1）混合。由于这两个水源水质量的DO的差异，它们的混合比最终决定了最终到达缺氧区的ECS底层水的初始DO供应。该水团混合物在侵入台湾东北端东中国海后，在其移动过程中（约60天）也发生了地球化学蚀变。沿着入侵的底部抱水的路径，我们发现系统的营养盐浓度和表观氧利用率的增加，或下降的溶解氧以下Redfield化学计量作为海洋有机质分解的结果。这些非局部因素对CJP底层水的初始DO施加协同控制，促进缺氧的形成，尽管CJP底层水的停留时间相对较短（约11天）。我们认为，这样的远场驱动因素应该考虑在内，以更好地预测未来的情况下，沿海缺氧的全球变暖的背景下。
The East China Sea (ECS) off the Changjiang (Yangtze River) Estuary, located around the near field of the Changjiang plume (CJP) is a hot spot where phytoplankton blooms in the surface water and hypoxias in the subsurface/bottom waters are frequently observed. Based on field observations conducted in summer 2009 and 2011, we examined non-local drivers associated with the initial dissolved oxygen (DO) levels that had significant impact on the development of summer hypoxias in the ECS off the Changjiang Estuary. The bottom water mass therein could be traced isopycnally at 24.2 < σθ< 25.2 back to the vicinity of the Luzon Strait, ∼1300 km upstream, where subsurface Kuroshio water (∼220 m deep with ∼190 μmol DO kg−1) mixed with the South China Sea subsurface water (∼120 m deep with ∼130 μmol DO kg−1). Owing to the difference in DO of these two source water masses, their mixing ratio ultimately determined the initial DO supply to the ECS bottom water that eventually reached the hypoxic zone. This water mass mixture was also subject to biogeochemical alteration during its travel (∼60 days) after it intruded into the ECS at the northeastern tip of Taiwan. Along the pathway of the intruded bottom-hugging water, we found systematic increases in nutrient concentrations and apparent oxygen utilization, or drawdown in DO following Redfield stoichiometry as a result of marine organic matter decomposition. These non-local factors exerted a synergistic control on the initial DO of CJP bottom water promoting hypoxia formation, although the residence time of the CJP bottom water was relatively short (∼11 days). We contend that such far field drivers should be taken into account in order to better predict the future scenarios of coastal hypoxias in the context of global warming.
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影响因子：
3.3
作者：
Chen, Chung-Chi;Gong, Gwo-Ching;Shiah, Fuh-Kwo
通讯作者：
Shiah, Fuh-Kwo
影响因子：
3
作者：
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通讯作者：
Zhuoyi Zhu;Jing Zhang;Ying Wu;Ying-ying Zhang;Jing Lin;Sumei Liu
影响因子：
64.8
作者：
Grantham, BA;Chan, F;Menge, BA
通讯作者：
Menge, BA
影响因子：
2.3
作者：
Y. Chen;Houng-Yung Chen;G. Gong;Yen-Huei Lin;S. Jan;M. Takahashi
通讯作者：
Y. Chen;Houng-Yung Chen;G. Gong;Yen-Huei Lin;S. Jan;M. Takahashi
DOI：
10.1360/02yd9110
发表时间：
2002-12
期刊：
Science in China Series D: Earth Sciences
影响因子：
--
作者：
Daoji Li;Jing Zhang;Daji Huang;Ying Wu;Jun-Ze Liang
通讯作者：
Daoji Li;Jing Zhang;Daji Huang;Ying Wu;Jun-Ze Liang