UBC Theses and Dissertations
Temperature microstructure in Howe Sound Bilodeau, Laurent Ernest
Temperature microstructure observations obtained in Howe Sound are presented and related to their oceanographic context, In some instances, two free-falling probes have been launched simultaneously with separations of 10 to 20 m at the surface in an attempt to look at the lateral extent of temperature microstructure features. Patches of temperature gradient variance were found where the gradient presented peak values of both signs at smaller scales. These patches were usually observed by one probe only and seem to extend laterally over less than 20 m. In other instances the peak gradient values took mostly the same sign within a given patch. Such patches were usually detected by both probes, indicating that their horizontal extent is significantly larger than 20 m. These types of temperature microstructure are also discussed in terms of mechanisms that could provide an explanation for their existence. In Howe Sound's Inner Basin, the Deep Water occasionally receives large influxes of water from the Strait of Georgia. Otherwise, it stays essentially trapped behind a 75 m deep sill and becomes more homogeneous with time. A model is presented which relates the rate at which temperature becomes homogeneous to temperature gradient variance and the molecular coefficient of heat diffusion. Other parts of the water column are discussed in terms of the Osborn-Cox (1972) model of vertical heat transport.
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