Marine heatwaves off eastern Tasmania: Trends, interannual variability, and predictability

作者：Oliver Eric C J^*; Lago Veronique; Hobday Alistair J; Holbrook Neil J; Ling Scott D; Mundy Craig N

来源：Progress in Oceanography, 2018, 161: 116-130.

DOI：10.1016/j.pocean.2018.02.007

• Extreme events
• Climate change
• Climate variability
• Ocean modelling
• Self-organising maps

Surface waters off eastern Tasmania are a global warming hotspot. Here, mean temperatures have been rising over several decades at nearly four times the global average rate, with concomitant changes in extreme temperatures - marine heatwaves. These changes have recently caused the marine biodiversity, fisheries and aquaculture industries off Tasmania's east coast to come under stress. In this study we quantify the long-term trends, variability and predictability of marine heatwaves off eastern Tasmania. We use a high-resolution ocean model for Tasmania's eastern continental shelf. The ocean state over the 1993-2015 period is hindcast, providing daily estimates of the three-dimensional temperature and circulation fields. Marine heatwaves are identified at the surface and subsurface from ocean temperature time series using a consistent definition. Trends in marine heatwave frequency are positive nearly everywhere and annual marine heatwave days and penetration depths indicate significant positive changes, particularly off southeastern Tasmania. A decomposition into modes of variability indicates that the East Australian Current is the dominant driver of marine heatwaves across the domain. Self-organising maps are used to identify 12 marine heatwave types, each with its own regionality, seasonality, and associated large-scale oceanic and atmospheric circulation patterns. The implications of this work for marine ecosystems and their management were revealed through review of past impacts and stake-holder discussions regarding use of these data.

• 出版日期2018-2