Internal tides can provide thermal refugia that will buffer some coral reefs from future global warming.Observations show ocean temperatures are rising due to climate change, resulting in a fivefold increase in the incidence of regional-scale coral bleaching events since the 1980s; analyses based on global climate models forecast bleaching will become an annual event for most of the world's coral reefs within 30-50 yr.  Internal waves at tidal frequencies can regularly flush reefs with cooler waters, buffering the thermal stress from rising sea-surface temperatures.  Our results demonstrate how these effects could delay bleaching for corals, providing thermal refugia. 
THERM