Australian Multi-decadal Ocean Time Series EXTreme (AMDOT-EXT) Data Products (Version 2.0)

Presented are multi-decadal observational records of extreme ocean temperature events derived from temperature data obtained at 4 monitoring sites around Australia. These sites include the 3 long-term National Reference Stations at Port Hacking (PHB, ~ 151.2E, 34.1S), Maria Island (MAI, ~ 148.2E, 42.6S), and Rottnest Island (ROT, ~ 115.4E, 32S) in ~100 m, 90m and 55m of water respectively and a fourth long-term site off Port Hacking in 50 m of water (PHA). At all four locations sub-surface ocean temperature has been recorded nominally weekly to monthly since the 1940s or 50s from in situ bottle data. In recent years, the historic records have been augmented with data obtained from additional observational platforms including moored sensors, vertical CTD profiles and satellite-derived data.

We provide data files with indices indicating the timings of extreme temperature events (including marine heatwaves (MHW), cold spells (MCS) and shorter duration heat spikes and cold spikes), their intensity, and the corresponding temperature time series and climatology thresholds. For MHWs and MCSs (defined as anomalies above the 90th percentile lasting more than 5 days) we also provide further event information, such as their category, and onset and decline rates. The temperature data used have been quality controlled and combined. The 4 data products are provided as CF-compliant NetCDF files, and the data collection is supported by Australia’s Integrated Marine Observing System and data are open-access.

This dataset supersedes an earlier version - https://catalogue-imos.aodn.org.au:443/geonetwork/srv/api/records/a1f18656-a973-4d19-a2c8-adc37de5499b.
The temporal extent of the data products has been extended to include additional data from the V1 end date until late 2023. Additionally, climatologies calculated using data extended to late 2023 have been used to derive extreme temperature event characteristics.