In the ocean, extreme warming conditions are also becoming more frequent and intense. Two new studies from the Woods Hole Oceanographic Institution (WHOI) investigate marine heatwaves and currents at the edge of the continental shelf, which impact regional ocean circulation and marine life. During El Niño periods, the temperature and salinity anomalies associated with marine heatwaves are limited to the ocean surface, showing that complex ocean processes play an important role in the depth-extent of extreme events. Ryan and her colleagues are using a similar modeling approach to study marine heatwaves in the Northwest Atlantic. “The challenge, wherever you go, is that marine heatwaves have so many drivers,” Ryan said.