Seminar: Dr. Nancy Soontiens

Please join us as we welcome Dr. Nancy Soontiens from the department of Earth, Ocean and Otmospheric Sciences at the University of British Columbia for her seminar titled Mixing, Transport, and Deep Water Renewal in a Sill-Basin Estuarine System. Refreshments will be served.

Abstract

Estuarine circulation is characterized by an exchange of fresh surface water overlying a dense undercurrent of saline water from the ocean. This exchange is influenced by tidal mixing, wind forcing, and river discharge, the details of which are determined by the properties of each estuary. In the sill-basin system between the Straits of Juan de Fuca and Georgia on the west coast of Canada, tidal mixing over complicated bathymetry plays an important role in the overall circulation and transport, and ultimately influences the renewal of dense, saline waters into the Strait of Georgia basin during summer months. This mixing is often difficult to accurately diagnose in numerical ocean models, especially in operational settings where demands on computational resources are high. In this talk, I will discuss the use of a baroclinic model of the Salish Sea, which includes the Strait of Juan de Fuca, the Strait of Georgia, Puget Sound and Johnstone Strait, to study transport and deep water renewal in this system. I will discuss the role of advective and mixing processes on the freshwater transport and will outline model sensitivities to several mixing parameterizations. Finally, I will discuss a numerical instability that strongly impacts the estuarine exchange in this system.