The California Current System (CCS) is a highly productive region because of wind-driven upwelling, which supplies nutrients to the euphotic zone. Numerous studies of the relationship between phytoplankton productivity and wind patterns suggest that an intermediate wind speed yields the most productivity on the shelf. However, few studies have considered the productivity-wind relationship across the entire CCS, including the Northern CCS (north of 42°N), an unusually productive region with highly variable upwelling- and downwelling-favorable winds. Using satellite chlorophyll concentration from GlobColour together with QuikSCAT and ASCAT winds, we examine the relationship between shelf (shallower than the 150 m isobath) chlorophyll concentration and wind patterns in the Central and Northern CCS. Results from this empirical analysis suggest that while there is a dome-shaped relationship between mean chlorophyll concentration and wind stress for the whole system, the Central CCS and Northern CCS have significantly different relationships, which is evident in the separation between their mean chlorophyll concentration-wind stress curves. The Northern CCS also supports high chlorophyll concentration during downwelling-favorable winds. To understand this difference in chlorophyll concentration-wind stress relationships, results from particle tracking experiments using a ROMS model of the Northern CCS are used to map shelf retention times with respect to wind patterns. These results suggest that on the 1°-latitude scale, the effect of wind intermittency on retention is minimal in the Northern CCS; however, this result does not disqualify the influence of more complex controls on retention like wind intermittency on smaller spatial scales. Lastly, we present a revised hypothesis to describe the relationship between chlorophyll concentration and wind stress in the CCS that includes the influence of non-upwelling-derived nutrients in the Northern CCS.

中文翻译：

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使用加州中部和北部洋流系统中的卫星数据将叶绿素浓度和风向联系起来

加利福尼亚洋流系统 (CCS) 是一个高产地区，因为风力驱动的上升流为透光区提供养分。对浮游植物生产力和风模式之间关系的大量研究表明，中等风速在架子上产生最大的生产力。然而，很少有研究考虑整个 CCS 的生产力与风的关系，包括北 CCS（北纬 42°以北），这是一个异常生产力的地区，具有高度可变的上升流和下降流有利风。使用来自 GlobColour 的卫星叶绿素浓度以及 QuikSCAT 和 ASCAT 风，我们研究了 CCS 中部和北部大陆架（低于 150 m 等深线）叶绿素浓度与风模式之间的关系。该实证分析结果表明，虽然整个系统的平均叶绿素浓度与风应力之间存在圆顶形关系，但中部 CCS 和北部 CCS 之间的关系存在显着差异，这从它们的平均叶绿素浓度-风应力曲线。北部 CCS 还支持在有利于下流的风中的高叶绿素浓度。为了理解叶绿素浓度-风应力关系的这种差异，使用北部 CCS ROMS 模型的粒子跟踪实验结果用于绘制与风模式相关的货架保留时间。这些结果表明，在 1° 纬度范围内，北 CCS 中风间歇性对保持力的影响最小；然而，这一结果并没有取消更复杂的控制对保留的影响，如较小空间尺度上的风间歇性。最后，我们提出了一个修正的假设来描述 CCS 中叶绿素浓度与风应力之间的关系，其中包括北 CCS 中非上升流衍生营养素的影响。