Collaborative Research: Asymmetric Circulation in Wind-Driven Bays

一个最近的分析模型预测，当盆地深度大于Ekman深度时，小型沿海盆地中的风驱动环流从根本上受到地球自转的影响。旋转会影响流体包裹轨迹的性质和复杂性，对混合和停留时间产生重要影响。将结合观测、分析和数值模拟来验证和扩展这一模型。将于2004-2005年冬季在墨西哥下加利福尼亚半岛加州湾一侧的巴伊亚孔塞普西翁进行实地观测。该海湾在整个冬季都受到强风的影响，垂直混合良好。观测将包括系泊仪器、船上勘测和漂流器部署，科学目标是：（a）通过观测描述旋转如何影响风驱动的环流以及暴露于强风的相对较深、混合良好的半封闭海湾中与海洋的交换，以及（B）扩展分析模型以表示由潮汐和横向密度梯度驱动的环流，并用数值模型描述平流和垂直分层如何改变这种环流。（海湾、河口、泻湖）与它们的大小不成比例。除其他生态功能外，泻湖和河口还可作为鸟类迁徙的中转站、动植物群植物群的苗圃以及某些海洋哺乳动物的交配和产犊地。与此同时，这些水体受到人类活动的深刻影响。通过对控制这些盆地环流和与海洋交换的过程进行动态描述，这项研究将有助于通过科学管理和工程实践，最大限度地减少污水排放等人类影响。此外，该项目代表了与墨西哥科学家的国际合作，支持两名研究生。其中一名PI是代表性不足的群体的成员。这项研究还将使包括少数群体在内的大学生参与研究。

ABSTRACTOCE-0425147 Asymmetric circulation in wind-driven baysIntellectual MeritA recent analytical model predicts that the wind-driven circulation in small coastal basins is fundamentally influenced by the Earth's rotation when the basin depth is greater than the Ekman depth. Rotation affects the character and complexity of fluid parcel trajectories, with important consequences for mixing and residence times. A combination of observations and analytical and numerical simulations will be conducted to verify and extend this model. Field observations will be done during the winter season 2004-2005 in Bahia Concepcion, on the Gulf of California side of the Baja California peninsula in Mexico. The bay is subject to strong wind forcing throughout the winter, when it is vertically well mixed. The observations will include moored instrumentation, shipboard surveys and drifter deployments and the scientific objectives are:(a) to describe through observations how rotation affects the wind-driven circulation and the exchange with the ocean in a relatively deep, well-mixed, semi-enclosed bay that is exposed to strong winds, and(b) to extend the analytical model to represent the circulation driven by tides and by lateral density gradients, and to describe with numerical models how advection and vertical stratification modify this circulation.Broader ImpactsThe ecological and societal importance of small coastal basins (bays, estuaries, lagoons) is out of proportion with their size. Among other ecological functions, lagoons and estuaries serve as way stations for bird migration, as nurseries for fauna and flora and as mating and calving grounds for certain marine mammals. At the same time these water bodies have been deeply impacted by anthropogenic activities. By developing a dynamical description of the processes that control circulation in these basins and exchange with the ocean, this study will help minimize human impacts such as sewage discharge through science-based management and engineering practices. In addition, this project represents international collaboration with Mexican scientists, supports two graduate students. One of the PIs is a member of an underrepresented group. The study will also expose undergraduates, including minority groups, to research.