Speed Presentation 2024 Australian Marine Sciences Association Annual Meeting combined with NZMSS

Mesoscale Modulation of south-east Australian Coastal Ocean Temperatures in a Regional Ocean Model.  (#488)

John Reilly 1 , Chris Chapman 2 , Neil Holbrook 1 , Courtney Quinn 3 , Jules Kajtar 1
  1. Institute for Marine and Antarctic Studies , University of Tasmania, Hobart, TAS, Australia
  2. Environment, CSIRO, Hobart, TAS, Australia
  3. Mathematics, University of Tasmania, Hobart, TAS, Australia

The eastern Tasmanian continental shelf seas are warming faster than any other nearshore region along Australia's east coast. The regions exposure to the rapidly warming EAC Extension is thought to be driving this trend, however present modelling capabilities have hindered the identification of multiscale dynamical processes connecting the shelf temperatures to the mesoscale offshore circulation. We demonstrate with a new "ultra high" resolution regional ocean model, that eddy-shelf interactions lead to anomalous episodic heat injections onto the shelf from offshore, resulting in MHW conditions nearshore. The timescales and frequency of these dynamical events are explored, and placed in the context of the rapidly warming waters both on and off the shelf in the SW Tasman Sea region. Furthermore, implications for industry and policy makers are discussed in terms of the predictability of extreme events along Tasmania's east coast. Finally, the results will be extrapolated to other ecologically and economically important regions.