Under a warming climate and the associated increase in ocean heat content, we are expecting an increase in the frequency and potentially the severity and duration of marine heatwaves (MHW). The MHWs can have significant impacts on marine ecosystems, impacting species habitat range, ecosystem structure, biodiversity, and also affecting marine industries such as fisheries and aquaculture.

The Integrated Marine Observing System’s (IMOS) infrastructure such as satellite remote sensing and marine in-situ infrastructure, together with global ocean and climate forecasts provide a sound platform of simulations and observations that help predict and observe the development of MHWs at ocean basin and regional scales. Although the signature of MHWs are detected in the surface water through satellite remote sensing, understanding their subsurface structure in near real-time is limited. In addition, regions such as the tropics with high cloud cover during the warm summer months, remote sensing techniques prevent the monitoring thermal anomalies over a broad coastal regions.

The new IMOS event-based glider facility aims to enable more accurate and relevant observations of the subsurface ocean temperature structure and other bio-physical parameters (e.g. oxygen concentration, chlorophyll fluorescence, CDOM, light from four irradiance wavelengths) during the development and deterioration stages of MHWs around the Australian coast. The ocean gliders provide an agile observing platform that is remotely operated and can be deployed within a week to provide real-time subsurface data for periods of 3-5 weeks.

The first IMOS event-based glider deployment was February 2019 off the east coast of Tasmania, where a MHW occurred, with an additional deployment in March 2019. We expect that data from these glider missions will provide information to help develop a better understanding of the mechanisms that affect temperatures in the water and generation of MHW.