Transport and mixing of particles in stratified environmental flows.

加拿大毗邻世界上最大的内陆湖系统，拥有世界上最长的海洋海岸线。这些重要水生系统的成功环境管理需要清楚地了解沉积物、营养物质和化学品是如何被稀释的，并从人口密度高的地区输送到敏感的生态生境。在这笔赠款中，我们侧重于颗粒运输的三个基本方面的潜在物理过程：沉积物在海底积累的地方，来自河流的沉积物如何填充港口和河口，以及微塑料的传播，这损害了我们湖泊中的鱼类。我的研究项目通过实验室实验、数学建模和实地研究来研究这些过程。在第一个目标中，我们将为海底一些最大的沉积物沉积的演化开发新的概念模型，并确定这些大型沉积物的形状如何受到洋流速度的影响。在第二个目标中，我们将讨论河流中的泥沙流进入层状湖泊或沿海海洋的情况，了解泥沙沉降的速度是很重要的，因为这决定了泥沙形成的规模。在第三个目标中，我们将确定风力驱动的湍流和水流如何控制五大湖中浮力微塑料颗粒的垂直和水平传播，这将是帮助政府机构管理这种形式的污染对环境影响的重要一步。*总体而言，我的国际公认的NSERC研究计划旨在了解控制分层湖泊和沿海海洋中颗粒、化学品和生物的运输和混合的物理过程。为了让我的研究植根于紧迫的实际问题，我与联邦、省和市各级的环境机构合作。这些伙伴关系还使我能够利用额外的资金进行更大的实地考察项目，并确保我们的新科学被相关当局用来帮助制定管理决策。拟议的研究将促进我们对与加拿大的社会经济和环境需求相关的环境流体动力学的理解。

Canada borders the world's largest inland lake system, and has the world's longest ocean coastline. The successful environmental management of these important aquatic systems requires a clear understanding of how sediment, nutrients, and chemicals are diluted and transported from high-density population areas to sensitive ecological habitats. In this grant, we focus on the underlying physical processes of three basic aspects of particle transport: where sediment accumulates on the ocean floor, how sediments from rivers fill in harbours and estuaries, and the spread of micro-plastics, which hurt fish in our lakes. My research program studies these processes with laboratory experiments, mathematical modeling, and field studies. In the first aim, we will develop new conceptual models for the evolution of some of the largest sediment deposits on the ocean floor and determine how the shape of these large sediment deposits is influenced by the speed of the ocean currents. In the second aim, we will address the situation where a sediment-laden flow of a river enters into a stratified lake or the coastal ocean and it is important to know how fast the sediment settles, as this determines the scale over which sediments deposits form. In the third aim, we will establish how wind-driven turbulence and currents control the vertical and horizontal spread of buoyant micro-plastic particles in the Great Lakes, which will be an important step in helping government agencies manage the environmental impacts of this form of pollution. ***Overall, my internationally-recognized NSERC program of research is directed at understanding the physical processes that control transport and mixing of particles, chemicals and biology in stratified lakes and the coastal ocean. To keep my research rooted in urgent, practical concerns, I collaborate with environmental agencies at the federal, provincial and municipal levels. These partnerships have also allowed me to leverage additional funds for a larger program of fieldwork, and to ensure that our new science is used by relevant authorities to help formulate their management decisions. The proposed research will advance our understanding of environmental fluid dynamics relevant to Canada's socioeconomic and environmental needs.********