Characteristics and drivers of marine heatwaves in the western South Atlantic

Marine heatwaves are events of extreme warming in the ocean and have devastating consequences for marine life. Here we used a K-mean clustering analysis to detect different types of marine heatwaves along the South American coast from 10°S to 45°S and identify their remote drivers. In the central part of the domain, marine heatwaves are associated with atmospheric blocking caused by wave trains triggered by the Madden-Julian Oscillation. On the other hand, marine heatwaves occurring along the northern and southern coast of South America are associated with El Niño and La Niña events, respectively. The intensity and duration of these marine heatwaves are modulated by the development phase and intensity of the Niño and Niña events. By identifying the climatic modes of variability leading to each type of marine heatwaves, our study can help develop adaptation strategies, such as early warning systems, to prevent the devastating effects of marine heatwaves.