Modeling the long-term variability of phytoplankton functional groups and primary productivity in the South China Sea
Modeling the long-term variability of phytoplankton functional groups and primary productivity in the South China Sea
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DOI：
10.1007/s10872-013-0190-8
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发表时间：
2013-07
影响因子：
2.3
通讯作者：
Wentao Ma;F. Chai;P. Xiu;H. Xue;Jun Tian
中科院分区：
文献类型：
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作者：
Wentao Ma;F. Chai;P. Xiu;H. Xue;Jun Tian
初级生产力（PP）和浮游植物结构在调节海洋碳循环中起着重要作用。南海独特的季节环流和上升流格局为研究营养盐和浮游植物动态对气候变化的响应提供了理想的天然实验室。在这项研究中，我们使用了一个三维（3D）物理-地球化学耦合模型，以模拟营养盐，浮游植物生物量，PP，和功能群在南海1958年至2009年。模拟结果表明，小型浮游植物、硅藻和颗石藻的年平均碳组成分别为33.7%、52.7%和13.6%。硅藻表现出较高的季节性变化比小型浮游植物和颗石藻。除越南东南部近海夏季和冬季均出现硅藻水华外，南海大部分海域冬季硅藻数量丰富。小型浮游植物和颗石藻的高值主要出现在夏季。我们的模拟结果表明，PP的季节变化是由东亚季风驱动的。东北冬季风导致吕宋岛西北部近海和巽他陆架的营养盐增加，而西南夏季风驱动沿岸上升流，为越南东南部近海带来充足的营养盐。在年际尺度上，模拟的PP与厄尔尼诺/南方涛动（ENSO）相关。ENSO的正位相（厄尔尼诺条件）对应于较低的PP，ENSO的负位相（拉尼娜条件）对应于较高的PP。
Primary productivity (PP) and phytoplankton structure play an important role in regulating oceanic carbon cycle. The unique seasonal circulation and upwelling pattern of the South China Sea (SCS) provide an ideal natural laboratory to study the response of nutrients and phytoplankton dynamics to climate variation. In this study, we used a three-dimensional (3D) physical–biogeochemical coupled model to simulate nutrients, phytoplankton biomass, PP, and functional groups in the SCS from 1958 to 2009. The modeled results showed that the annual mean carbon composition of small phytoplankton, diatoms, and coccolithophores was 33.7, 52.7, and 13.6 %, respectively. Diatoms showed a higher seasonal variability than small phytoplankton and coccolithophores. Diatoms were abundant during winter in most areas of the SCS except for the offshore of southeastern Vietnam, where diatom blooms occurred in both summer and winter. Higher values of small phytoplankton and coccolithophores occurred mostly in summer. Our modeled results indicated that the seasonal variability of PP was driven by the East Asian Monsoon. The northeast winter monsoon results in more nutrients in the offshore area of the northwestern Luzon Island and the Sunda Shelf, while the southwest summer monsoon drives coastal upwelling to bring sufficient nutrients to the offshore area of southeastern Vietnam. The modeled PP was correlated with El Niño/Southern Oscillation (ENSO) at the interannual scale. The positive phase of ENSO (El Niño conditions) corresponded to lower PP and the negative phase of ENSO (La Niña conditions) corresponded to higher PP.