Abstract Coral reefs are being degraded globally, largely due to coral bleaching from rising ocean temperatures. Internal bores, generated by nonlinear internal waves, can help mitigate this stress by delivering cooler, nutrient‐rich water to shallow reefs (< 20 m). Between October 2023 and April 2024, a field experiment at Mermaid Reef Atoll (Australia's North West) examined how these bores influence reef temperature. Moored instruments on the windward side recorded tidally driven bores advecting cooler offshore waters onto the forereef slope (17–40 m), causing rapid cooling of up to 6.9°C in 30 min. Some cold‐water pulses crossed the reef crest, cooling the shallow reef flat (< 8 m) by up to 4.4°C for minutes to hours. A heat budget analysis indicates that without internal bores, shallow reefs experience up to three times more heat advection, increasing bleaching risk. These findings highlight internal bores' critical role in reducing thermal stress and enhancing coral reef resilience under climate change.
Grimaldi et al. (Thu,) studied this question.