Extended Data Fig. 1: Values of DHM with a 4-month accumulation window vs DHW at the Great Barrier Reef over the 2001–2020 period.
From: Coral bleaching and mortality overestimated in projections based on Degree Heating Months
Comparisons of heat stress calculated for DHM using a 4-month window vs DHW (this figure) display patterns of disparity that are similar to comparisons of DHM under a 3-month window vs DHW (Fig. 1). Outer plots show cumulative frequency of heat stress (°C weeks) from DHM with a 4-month window vs DHW calculated from: observed SST data (a), and hindcast SST data (six CMIP5 climate models, b-g), for 2,014 reefs of Australia’s Great Barrier Reef over 2001–2020. The widely-used predictive criteria for substantial bleaching (≥4°C weeks but <8 °C weeks) and severe bleaching with substantial mortality (≥8 °C weeks) are shown by the shaded areas. Insets show scatter plots depicting every value of DHM plotted against the corresponding value of DHW, both expressed as °C weeks. DHM was standardised to a weekly basis through multiplication by four. Cumulative frequencies are normalised to one.
