High resolution altimetry products: Validation on the South-West coast of Australia K. Guihou (1 ), C. Langlais (1-2 ), P.Oke (1 ), R.Coleman (2 ), F. Birol (3) September 2, 2009 1 CSIRO, HOBART, TAS Australia, 2 UTAS HOBART, TAS Australia, 3 LEGOS CTOH, Toulouse, France 1 Introduction The coastal zone is a region of significant importance, especially under climate change with integrated ecosystem and coastal management. In terms of ocean forecasts, shelf modelling is necessary if we want to extend the predictability of the global opera- tional systems towards coastal and regional sub-systems. To increase the realism and accuracy of the predictions, the availability of coastal observations is crucial. Altimetry data over the coastal ocean remains largely unexploited and leads to gaps in coastal observing systems. The main problems come from the difficulties of high resolution corrections (e.g., tides, radiometer, etc) and land contamination in the altimeter footprint which have lead to rejection of data in the coastal zone. The Center for Topographic studies of the Oceans and Hydrosphere (CTOH) is a French Observation Service dedicated to satellite altimetry studies. A dedicated data processing system has been developed to recover information of high resolution over coastal areas: the X-track software (cf poster and contribution from Birol et al.). In this paper, we analyse the 300m (20 Hz) high resolution along track sea level anomalies provided as a regional product from CTOH along the south-west coast of Australia. The main ocean feature of interest in this area is the Leeuwin Current (LC), an atypical eastern boundary current, flowing poleward. It brings subtropical waters along the western Australian shelf (Dominguez, 2006). This induces a differ- ence of Sea Surface Height (SSH) with the colder Indian Ocean waters (Pattiaratchi, 2006). The LC has a seasonal cycle: it flows stronger during the winter, turning east- wards around Cape Leuuwin to flow up to Tasmania when the westerly winds are 1