The ocean, right now
There is no single definition of a marine heatwave. Different thresholds and baselines answer different questions, and which is appropriate remains an open argument. The working definition is the qualitative one the field shares: a prolonged, discrete, anomalously warm water event.
One framework has nonetheless become a common language: the hierarchical definition and category scheme of Hobday and colleagues. Its value is less that it is uniquely correct than that it lets results from different oceans and events be compared within a standardised framework. The map below shows today's ocean under that framework.
Explore the findings of the International Marine Heatwaves Working Group
Explore the findings of the International Marine Heatwaves Working Group
The Working Group maintains a collection of the research literature on marine heatwaves, from the definition papers through to the latest studies of impacts and prediction.