This website introduces the St. Lawrence Estuary Internal Wave Experiment (SLEIWEX), a Canadian university-government partnership, funded by CFCAS, NSERC, and CFI, to study the generation, propagation and dissipation of large-amplitude internal waves in the St. Lawrence - Saguenay coastal system.
Large-amplitude internal waves (see image to the right) may be generated by stratified tidal flows over bottom topographic features. It is thought that such waves may be an important source of mixing in coastal waters, which means that they play a key role in coastal ecosystems, circulation, pollutant dispersal, etc. However, there are open questions about all aspects of the process. The SLEIWEX team seeks answers by studying the waves through their whole life cycle, from formation, through propagation, and to their eventual decay.
Much of the work to date has focussed on the collision of internal waves with sloping bottoms, or "internal beaches", upon which the waves may break, causing strong localized mixing. This is a process the team has been investigating near Ile aux Lievres, pictured on the left (photo credit: La Société Duvetnor Ltée). Examination of the image shows foam lines in the water, hypothesized to be surface signatures of internal waves. For an animation of sea-surface signatures and for observations of wave-induced processes occurring on the slope of Ile aux Lievres, visit the Results tab.
The wave generation process is being studied at a second field site, the Saguenay Fjord (image to the right). Preliminary field observations made by the SLEIWEX team suggest that tidal flow over sills in the Fjord generates large-amplitude internal waves at regular intervals. This makes the site a sort of natural laboratory for the study of internal wave generation. Using numerical simulations, the team is narrowing down the timing and location of the wave generation, and tracing probable propagation routes, in preparation for more extensive field work. See the Results tab for results of numerical simulations.
Technically inclined visitors to this site are invited to have a look at the team's publications, and to contact team members with questions or ideas for collaboration