Modeling studies of the Leeuwin Current off Western and Southern Australia

• Main Author: Butler, Christopher L.
• Other Authors: Batteen, Mary L.
• Language: en_US
• Published: Monterey, California. Naval Postgraduate School 2013
• Online Access: http://hdl.handle.net/10945/30803

A high-resolution, multi-level, primitive equation ocean model is used to examine the response of an eastern boundary oceanic regime to thermal and wind forcing. The focus of this study is the anomalous Leeuwin Current System off Western and Southern Australia. Three types of experiments are conducted. The first type forces the model from rest with the Indian Ocean climatological temperature gradient as an initial condition only, while the second type repeats the first experiment with the added contribution of the North West Shelf water temperature profile. The role of irregular coastline geometry on the generation of currents and eddies is also examined by comparing these cases with and without an irregular (realistic) coastline. The third type, with an irregular coastline, forces the model from rest with constant thermal and wind forcing. A one-time application of the North West Shelf water is added during the model run. In all experiments, surface currents, undercurrents, meanders, and eddies are generated. The results from experiments with an irregular, rather than an idealized coastline, show preferred eddy generation locations. The results from the third type of experiment. which has the most realistic features, agrees well with available observations off Western and Southern Australia. These results support the hypothesis that both thermal and wind forcing are important mechanisms for the generation of many of the observed features in the Leeuwin Current System.