Abstract A mechanistic understanding of organismal movement provides context for existing biogeographic and ecological patterns and improves our ability to predict changing patterns in dynamic environments. Here, we examined the movement ecology of pelagic Sargassum in the northern Caribbean Sea, where major inundation events of this brown algae have become increasingly problematic to coastal communities. We used GPS-trackers affixed to Sargassum mats, standard oceanographic drifters, and “pseudo-Sargassum” drifters to acquire empirical data on the movement of Sargassum and ocean currents. We related these observed movements to ocean surface velocity fields from a global ocean circulation model and wind velocities derived from models and satellite observations. Specifically, we assessed whether adding a windage component to ocean surface velocities improved predictions generated by synthetic particles tracked within an ocean circulation model. We found that the inclusion of a windage factor of 1 to 3% reduced separation distances between synthetic particles and the tracks of Sargassum mats, pseudo-Sargassum drifters, and un-drogued oceanographic drifters. When similar analyses were conducted for oceanographic drifters with drogues centered at 15 m depth (which are designed to minimize the influence of winds and waves and thus served as a control for this technique), inclusion of a windage factor did not improve particle-tracking predictions. These findings indicate that adding a windage calculated from satellite-derived winds to the surface layer of an ocean circulation model produces particle-tracking results that are more relevant to Sargassum, likely by accounting for the buoyant nature of the algae and the influence of the direct forcing of wind (and waves, implicitly) on the part of the object extending above the surface. However, the estimates of an appropriate windage coefficient for Sargassum may differ depending on the wind and surface current products used as well as the particular oceanic region being studied. Future work to identify and resolve systematic biases in the representation of winds and currents will be an important step toward eventually forecasting Sargassum movement and coastal inundation events.

中文翻译：

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改进远洋马尾藻的运输预测

摘要 对有机体运动的机械理解为现有的生物地理和生态模式提供了背景，并提高了我们预测动态环境中变化模式的能力。在这里，我们研究了加勒比海北部的远洋马尾藻的运动生态学，在那里，这种褐藻的主要淹没事件对沿海社区来说变得越来越成问题。我们使用固定在马尾藻垫上的 GPS 跟踪器、标准海洋漂流器和“伪马尾藻”漂流器来获取有关马尾藻和洋流运动的经验数据。我们将这些观测到的运动与来自全球海洋环流模型的海洋表面速度场以及来自模型和卫星观测的风速相关联。具体来说，我们评估了向海洋表面速度添加风阻分量是否可以改进由海洋环流模型中跟踪的合成粒子生成的预测。我们发现，包含 1% 到 3% 的风阻系数可减少合成颗粒与马尾藻垫、假马尾藻漂流者和未垂尾海洋漂流者的轨迹之间的分离距离。当对带有以 15 m 深度为中心的锥套的海洋漂流器进行类似分析时（其设计目的是最大限度地减少风和波浪的影响，因此作为该技术的控制），包含风阻因子并没有改善粒子跟踪预测. 这些发现表明，将卫星风计算的风阻添加到海洋环流模型的表层会产生与马尾藻更相关的粒子跟踪结果，这可能是通过考虑藻类的浮力性质和直接影响风（和波浪，隐含地）作用在物体表面延伸的部分上。然而，马尾藻适当风阻系数的估计值可能会因所使用的风和表面流产品以及所研究的特定海洋区域而异。识别和解决风和洋流表示中的系统偏差的未来工作将是最终预测马尾藻运动和沿海淹没事件的重要一步。可能是通过考虑藻类的浮力性质以及风（和波浪，隐含地）对延伸到表面上方的物体部分的直接作用的影响。然而，马尾藻适当风阻系数的估计值可能会因所使用的风和表面流产品以及所研究的特定海洋区域而异。识别和解决风和洋流表示中的系统偏差的未来工作将是最终预测马尾藻运动和沿海淹没事件的重要一步。可能是通过考虑藻类的浮力性质以及风（和波浪，隐含地）对延伸到表面上方的物体部分的直接作用的影响。然而，马尾藻适当风阻系数的估计值可能会因所使用的风和表面流产品以及所研究的特定海洋区域而异。识别和解决风和洋流表示中的系统偏差的未来工作将是最终预测马尾藻运动和沿海淹没事件的重要一步。马尾藻适当风阻系数的估计值可能会因所使用的风和表面流产品以及所研究的特定海洋区域而异。识别和解决风和洋流表示中的系统偏差的未来工作将是最终预测马尾藻运动和沿海淹没事件的重要一步。马尾藻适当风阻系数的估计值可能会因所使用的风和表面流产品以及所研究的特定海洋区域而异。识别和解决风和洋流表示中的系统偏差的未来工作将是最终预测马尾藻运动和沿海淹没事件的重要一步。