Recruitment Dynamic in Event Driven Bank Circulations

戴维斯博士和合作者将开发一系列越来越复杂的模型，以研究风暴和海洋涡流对理想离岸银行浮游生物和鱼类幼虫平流损耗率的影响。他们的工作假设是，这样的“冲刷”事件导致了典型浮游动物（Calanus, pseudoalanus, Centropages, Paracalanus）和鱼类（鳕鱼，黑线鳕，鲱鱼）种群的招募大幅减少。虽然为了简单起见，他们关注的是银行循环，但这项工作将为物理作用力、食物网动态和招募之间的基本相互作用提供见解，这些相互作用可以应用于海洋的其他地区。研究人员将从一个简单的理想化的二维流动模型开始（将使用Georges bank参数值），然后将食物链和浮游动物种群动态的简单模型结合起来。包含简单生物学的欧拉模型将与包含更完整生物学的拉格朗日模型（使用由欧拉模型指定的流动轨迹）进行比较。我们将开发简化技术，在物理和生物强迫的主导尺度下，将生物复杂性降低到可接受的最低水平。将开发中等复杂程度的模型，如等高线动力学分析，以评估环对银行流通的影响。最后，他们将使用包含简化生物学的原始方程（PE）循环模型，并将结果与其他模型进行比较。原始方程模型将用于在强地形和分层条件下获得真实的动态流动，从而确定物理损失与生物分布之间的时空对应关系。

Dr. Davis and collaborators will develop a series of models of increasing complexity to examine the effects of storms and oceanic eddies on advective loss rates of plankton and fish larvae from an idealized offshore bank. Their working hypothesis is that such "wash-out" events cause major reduction in recruitment in characteristic zooplankton (Calanus, Pseudocalanus, Centropages, Paracalanus) and fish (cod, haddock, herring) populations. Although, for simplicity, they focus on bank circulation, the work will provide insights into basic interactions between physical forcing, food web dynamics, and recruitment which can be applied to other regions of the ocean. The researchers will start with a simple 2-D kinematic model of idealized flow around a bank (Georges Bank parameter values will be used) and will then incorporate simple models of food chain and zooplankton population dynamics. Eulerian models containing simple biology will be compared with Lagrangian ones (using flow trajectories specified from the Eulerian), containing more complete biology. We will develop simplification techniques to reduce biological complexity to a minimal acceptable level given dominant scales of physical and biological forcing. Models of intermediate complexity such as contour dynamics analyses will be developed to assess impact of rings on bank circulation. Finally, they will use a primitive equation (PE) circulation model containing simplified biology and compare the results with the other models. The primitive equation model will be used to obtain realistic dynamical flows given strong topography and stratification, so that temporal-spatial correspondence between physical losses and biological distributions can be determined.