SEMINAR: Coastal Ocean Observations in Western Australia: From Peddies to Dense Shelf Water Cascades

West Australian Integrated Marine Observation System (WAIMOS) is a node of the Integrated Marine Observation System (IMOS) where the main areas of interest are (1) the continental shelf and slope regions offshore Fremantle extending northwards to Jurien Bay; and, (2) the north-west shelf. In this presentation, the current status of the instrumentation deployed and example data highlights will be presented. The IMOS infrastructure located in these regions includes continental shelf moorings (ADCP, thermistor and water quality loggers); HFRadar (CODAR and WERA systems) for surface current measurements; ocean glider transects (Slocum and Seagliders) for subsurface water properties; passive acoustic sensors for whale monitoring; AUV transects for benthic monitoring and, remotely sensed data products (SST and ocean colour). In the north-west the infrastructure is designed to monitor the influence of north-west shelf region on Leeuwin Current dynamics whilst in the south-west region the emphasis is to define the interaction between the Leeuwin Current and its eddies with the continentalshelf currents. Example data collected from WAIMOS infrastructure will be presented with examples of integration of different data sets, in relation to the understanding of different processes operating in the region. These include: (1) Interaction between the Leeuwin Current and Capes Current. Here, the warmer, lower salinity southward flowing Leeuwin Current interacts with the cooler, higher saline northward flowing Capes Current creates regions of high horizontal shear and the generation of sub-meso scale eddies or ‘Peddies’; and, (2) cascade of dense water along the continental shelf and its interaction with upwelling water induced by upwelling.