The Role of Topography in Cross-Shelf-Break Tracer Exchange

地球的自转及其科里奥利力限制了沿海海洋和深海之间的水交换。这种有限的交换往往表现为搁架断裂位置附近水性质的重大变化，如颜色。各种进程可以打破这些动态约束，允许交换流动。其中之一是由水下峡谷等小尺度地形造成的。我们建议量化通过海底峡谷运输的特定的、对环境重要的示踪剂的数量。这些示踪剂包括硝酸盐(一种限制浮游生物生长的营养物质)、溶解的无机碳(可以向上涌出，增加二氧化碳进入大气的通量)，以及含有低氧的水(这可能导致货架上的缺氧)。我们将包括峡谷中发生的强化混合的影响，以及多个峡谷之间或峡谷与海角之间的水流相互作用的影响。我们的目标是确定多个峡谷在季节性循环中对陆架区域示踪剂通量的净影响。

The rotation of the Earth and its Coriolis force limit the exchange of water between the coastal ocean and the deep ocean. This limited exchange is often illustrated by significant changes in water properties, such as colour, near the location of the shelf-break. Various processes can break these dynamical constraints and allow exchange flow. One of these is caused by small scale topography such as underwater canyons. We propose to quantify the amount of specific, environmentally important tracers that are transported through submarine canyons. These tracers include nitrate (a limiting nutrient for plankton growth), dissolved inorganic carbon (which can be upwelled and increase the flux of CO2 to the atmosphere), and water containing low oxygen (which can cause anoxia on the shelf). We will include the impact of the enhanced mixing that occurs in canyons and the impact of flow interactions among multiple canyons or between canyons and headlands. Our goal is to determine the net impact of multiple canyons on tracer flux in a shelf region over seasonal cycles.