The formation of deep water masses is a significant high latitude oceanic process that ventilates the deep waters of the global ocean. It is a process that is active in the northern marginal seas and in the Arctic Ocean itself. This project will investigate the rate of ventilation of the Arctic Ocean by constraining a numerical model of its circulation with observed chemical tracer data. The tracer data may be used to calibrate and verify the theoretical description of the circulation that is provided by numerical models, and can help to define specific processes that are related to the maintenance of the vertical structure of the Arctic Ocean. One major unresolved question is the maintenance of the nutrient maximum at the halocline level, which has been ascribed to the advection of Pacific water through the Bering Strait, and to nutrient regeneration on the Arctic continental shelves. A second question is the extent to which Arctic Ocean ventilation is affected by brine formation on the shelves and its subsequent cascading into deep water at the shelf break. The particular advantage of chemical tracers in this context is that tracers provide information and limits on time scales, and so constrain the results (and increase the level of realism) of models that were designed to reproduce physical and dynamical processes.
