The research employed simulations from the Community Earth System Model version 2 (CESM v2). By running ocean-assimilated experiments and five-year hindcasts initialized annually between 1981 and 2020, the team rigorously tested the model’s ability to forecast these extreme thermal events. The findings indicate that for many ocean basins, both the frequency and the cumulative intensity of MHWs can be reliably predicted for periods ranging from several months to multiple years. However, the study also highlighted that the skill of these forecasts varies significantly depending on the specific region and the season being analyzed, underscoring the need for localized predictive tools.

A critical finding of the research concerns the primary drivers behind this forecast skill. In most identified hotspots, anthropogenic warming is established as the dominant factor contributing to the multi-year predictability. However, the study also revealed that internal climate variability imposes limits on predictability, particularly within the equatorial Pacific. Furthermore, larger coupled ocean-atmosphere processes, specifically the El Niño-Southern Oscillation (ENSO) and the Atlantic Multidecadal Oscillation (AMO), play a crucial role in modulating and influencing regional forecast accuracy. These large-scale climate oscillations introduce complexity, requiring detailed regional analysis to refine predictive models.

These results provide crucial insights into the sources and limitations of forecast skill across different marine environments. By identifying regions where advance warning is possible, the research offers a vital foundation for developing timely and targeted regional preparedness strategies. This predictive capability can significantly support coral reef conservation efforts and aid in adaptation strategies as these ecosystems face escalating thermal stress from climate change. The ability to anticipate MHW events on multi-year timescales allows managers to implement proactive measures, enhancing the resilience of these critical marine habitats against future climate impacts.

Subject of Research: Predictability of marine heat wave frequency and intensity in coral reef regions.

Article Title: Marine heat waves in vulnerable coral reef regions are skillfully predictable on multi-year timescales

Article References: Karwat, A., Lee, J.-Y., Franzke, C. L. E., Kim, Y.-Y., Kwon, E. Y., & Lee, S.-S. (2026). Marine heat waves in vulnerable coral reef regions are skillfully predictable on multi-year timescales. Nature Communications. https://doi.org/10.1038/s41467-026-78279-1

Image Credits: AI Generated

DOI: 10.1038/s41467-026-78279-1

Keywords: Marine Heat Waves, Coral Reefs, Climate Change, Predictability, Earth System Models, Oceanography, Anthropogenic Warming, Marine, heat, waves, vulnerable, coral