Marine heatwaves are modelled off their terrestrial namesakes and are prolonged periods of anomalously high sea surface temperature (SST). In effect, they are categorized SST anomalies. They are also a more general version of the Coral Reef Watch (CRW) daily global 5km coral bleaching "hot spots" product. Rather than being aimed specifically at corals, however, they provide a more generalized description of marine heat stress that is likely applicable to a broader range of marine life.
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