Application of a data‐assimilation model to variability of Pacific sardine spawning and survivor habitats with ENSO in the California Current System
Application of a data‐assimilation model to variability of Pacific sardine spawning and survivor habitats with ENSO in the California Current System
复制标题
应用数据同化模型研究加利福尼亚洋流系统中 ENSO 影响的太平洋沙丁鱼产卵和幸存者栖息地的变化
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
D. Checkley
中科院分区：
文献类型：
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作者：
Hajoon Song;A. Miller;S. McClatchie;Edward D. Weber;K. Nieto;D. Checkley
[1]太平洋沙丁鱼（Sardinops sagax）的产卵栖息地面积，产卵栖息地的质量和幸存者栖息地的可用性显着差异，太平洋经历了拉尼娜状态在2002年4月到2003年4月的弱厄尔尼诺。在2006-2007年的另一个厄尔尼诺/南方涛动过渡期，当厄尔尼诺状态消退和拉尼娜回归时，产卵栖息地质量出现了类似的模式。大气强迫，物理海洋状态和沙丁鱼卵产卵的属性之间的耦合进行了研究，使用动态一致的数据同化适合在这几个月的物理海洋观测。使用区域海洋模拟系统四维变分同化平台沿着进行拟合，并使用被动示踪剂进行伴随模型运行，以推断感兴趣区域的源沃茨。使用数据同化模型运行的分析表明，异常强大的赤道风强迫驱动离岸运输在拉尼娜条件下，扩大了沙丁鱼的产卵栖息地进一步离岸。沙丁鱼产卵栖息地的统计模型显示更好的栖息地质量在厄尔尼诺现象的条件下，这是与较高的蛋密度，并对应于更高的日产蛋量。卵的浓度也因水的汇聚而增加。源沃茨分析使用伴随数据同化模式的结果支持的想法，离岸运输扩展产卵栖息地，并显示，更高水平的营养物质被带到产卵栖息地与高浓度的沙丁鱼卵。
[1] The Pacific sardine (Sardinops sagax) showed significant differences in spawning habitat area, spawning habitat quality and availability of survivor habitat as the Pacific Ocean went through the La Nina state in April 2002 to a weak El Nino in April 2003. During another El Nino/Southern Oscillation transition period in 2006–2007 when the El Nino state retreated and the La Nina returned, a similar pattern in spawning habitat quality was seen. The coupling between the atmospheric forcing, the physical ocean states and the properties of the sardine egg spawning are investigated using dynamically consistent data-assimilation fits of the available physical oceanographic observations during these months. Fits were executed using the Regional Ocean Modeling System four-dimensional variational assimilation platform along with adjoint model runs using a passive tracer to deduce source waters for the areas of interest. Analysis using the data-assimilation model runs reveals that unusually strong equatorward wind-forcing drives offshore transport during the La Nina conditions, which extends the spawning habitat for sardine further offshore. A statistical model of sardine spawning habitat shows better habitat quality during the El Nino conditions, which is associated with higher egg densities and corresponded to higher daily egg production. Concentration of eggs is also increased by convergence of water. The results of the source waters analysis using the adjoint data assimilation model support the idea that offshore transport extends the spawning habitat, and show that higher levels of nutrient are brought into the spawning habitat with high concentration of sardine eggs.