Fig. 6: The propagation of mesoscale sea level anomalies (SLAs) around Moorea highlighting contrasting eddy fields during the 2016 and 2019 marine heatwaves (MHWs).

Satellite altimetry shows a the long-term trends in SLAs along the latitude of Moorea (−17.5°; horizontal dashed line indicates longitude of −149.83°) and b changes in SLAs north of Moorea (dotted grey line) relative to in-situ SLAs measured at 10 m depth over the north shore fore reef (solid black line). c Lower SLA and a cyclonic eddy north of Moorea in 2016 contrasts with d higher SLAs and an anticyclonic eddy to the north of Moorea in 2019. Local surface MHW events (see Table S4) are shown in b (orange shading). Dates in c, d correspond to the peak SLA measured over the north shore reef slope during the two most recent MHWs (12 April 2016 and 16 April 2019, respectively; see Fig. 7c). Note there is a colour scale difference between a and c–d due to differences in spatial and temporal coverage. Coastlines in c and d based on Wessel and Smith⁷⁷.