Fig. 6: Illustration of surface‒subsurface compound marine heatwaves (MHWs) and their extension depths.
From: Intensification of future subsurface marine heatwaves in an eddy-resolving model
A compound surface‒subsurface MHW refers to a MHW that occurs simultaneously and continuously from the surface to deeper layers. For instance, examples 1 and 2 qualify as compound MHWs, with depths of 50 m and 100 m, respectively. In examples 3 and 4, there is a break in continuity; taking only the portion before the break, example 3 is a compound MHW with a depth of 50 m, while example 4 occurs only at the surface and cannot be classified as a compound MHW. In example 5, no MHW occurs at the surface, so it also cannot be classified as a compound MHW.
