Revisiting the La Nina 1998 phytoplankton blooms in the equatorial Pacific
Revisiting the La Nina 1998 phytoplankton blooms in the equatorial Pacific
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DOI：
10.1016/j.dsr.2009.12.008
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发表时间：
2010-04-01
影响因子：
2.4
通讯作者：
Moulin, C.
中科院分区：
文献类型：
--
作者：
Gorgues, Thomas;Menkes, C.;Moulin, C.
利用热带太平洋生物地球化学模型评估了1997-1998年厄尔尼诺期间西太平洋铁源的年际变化对太平洋中部和东部铁有限生态系统的影响。本文进行了参考模拟和西太平洋铁源的两个模拟。两个“源”模拟的不同之处只是铁源的时间变化。在变源模拟中，源区铁浓度与新几内亚海岸暗流（NGCUC）的流速成正比；在恒源模拟中，施加相同的时间平均铁浓度，没有时间变化。变量源的设计是为了模拟新几内亚东北坡到NGCUC的铁通量的变化，这是由于沉积铁再悬浮的调节，正如之前的假设那样。通过这些模拟的比较，似乎：(i) NGCUC中的铁源，无论其来源变异性如何，都会增加赤道东太平洋的生物量，因为赤道潜流对东部的铁通量更大；（ii） NGCUC中的可变铁源不会改变东太平洋叶绿素的时间变异性，特别是1998年6月水华的时间和强度。如风力驱动的上升流，局部深度的温跃层。热带不稳定波和高放牧压力等生物过程。因此，尽管西太平洋溶解铁的来源在我们的模型中对维持赤道太平洋每年的综合生产很重要，但它们不太可能强烈限制太平洋中部和东部的水华时间，如1998年拉尼娜期间(C) 2010 Elsevier Ltd.)。版权所有
A biogeochemical model of the tropical Pacific has been used to assess the impact of interannual variability in a western Pacific iron source on the iron-limited ecosystem of the central and eastern Pacific during the 1997-1998 El Nino A reference simulation and two simulations with an iron source in the western Pacific have been performed The two "source" simulations differed only in the temporal variability of the iron source. In the variable source simulation, the iron concentration in the source region was proportional to the velocity of the New Guinea Coastal Undercurrent (NGCUC) In the constant source simulation, the same time-averaged concentration of iron was imposed with no temporal variability. The variable source was designed to mimic variations of iron flux from the northeast slope of New Guinea to the NGCUC due to modulation of sedimentary iron resuspension as previously hypothesized Through the comparison of these simulations, it appeared that: (i) an iron source in the NGCUC, regardless of its source variability, increases biomass in the eastern equatorial Pacific because of the greater eastward iron flux by the Equatorial Undercurrent and (ii) a variable NGCUC iron source does not change the temporal variability of eastern Pacific chlorophyll, and in particular the timing and intensity of the June 1998 bloom To explain eastern Pacific biological variability, local rather than remote processes are needed, such as wind-driven upwelling, the local depth of the thermocline. tropical instability waves and biological processes such as high grazing pressure. Therefore, while the western Pacific sources of dissolved iron are important in our model to sustain annually integrated equatorial Pacific production, they are unlikely to strongly constrain the timing of blooms in the central and eastern Pacific such as during the 1998 La Nina (C) 2010 Elsevier Ltd. All rights reserved