Indian Ocean Warming Pattern, Surface and Subsurface Marine HeatwaVEs: Storylines and Mechanisms (IO-WAVE)

Objective

The Indian Ocean (IO), home to nearly one-third of the global population, is the fastest-warming tropical basin under human influence. Its uneven warming affects monsoons, ecosystems, and extremes such as marine heatwaves (MHWs)-periods of anomalously warm ocean temperatures that increasingly disrupt coral reefs, tuna fisheries, and productive upwelling systems. MHWs are modulated by climate modes such as the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD), while intensifying most in regions of strongest anthropogenic warming. Yet the IO remains far less studied than the Pacific and Atlantic, leaving critical gaps in understanding the drivers, model representation, and future evolution of MHWs. IO-WAVE will address these gaps by: (i) evaluating how climate models reproduce observed IO warming, climate modes, and MHWs; (ii) assessing how the warming pattern and changes in climate modes influence future MHWs in the CMIP database; and (iii) downscaling these large-scale drivers with high-resolution simulations. A distinctive feature is the focus on subsurface MHWs, still poorly explored but strongly affecting ecosystems. By combining climate model evaluation, dynamical downscaling, and analysis of surface and subsurface MHWs, IO-WAVE will deliver the first comprehensive assessment of the IO warming-MHW nexus. It will generate storylines of plausible MHW futures across warming levels. IO-WAVE will be hosted at IRD/LOCEAN-IPSL (France) under the joint supervision of Drs. Jérôme Vialard and Camila Artana. A secondment at Mercator Ocean International, Europe's leader in operational oceanography, will ensure that scientific outcomes also benefit society. The fellowship will provide new skills in large-scale climate variability and downscaling, while leveraging the fellow's expertise on MHWs, fine-scale processes, and the IO.