Processed Marine Heatwave Metrics and Time-of-Emergence Analysis for Global Oceans (CMIP6 and OISST)

This dataset contains processed marine heatwave (MHW) metrics and time-of-emergence (ToE) analysis outputs supporting the manuscript: "Imminent Emergence of Permanent Marine Heatwave States Across Global Oceans", submitted to Earth's Future. The dataset includes marine heatwave characteristics derived from satellite observations (NOAA OISST v2.1, 1982–2024) and 21 CMIP6 Earth system models under historical, SSP2-4.5, and SSP5-8.5 scenarios. Marine heatwave events were detected following Hobday et al. (2016, 2018) using a seasonally varying 90th percentile threshold computed from a 1985–2014 baseline. Three metrics were calculated per grid cell per year: • Marine heatwave frequency (events per year) • Mean marine heatwave intensity (°C) • Annual marine heatwave days Time of emergence was determined using Kolmogorov–Smirnov tests comparing sliding 20-year windows against the baseline climatology. Emergence timing was assessed using multi-model agreement thresholds of 50%, 80%, and 100%. The dataset includes: • Processed MHW metrics derived from observed OISST data • Processed MHW metrics derived from CMIP6 models • Kolmogorov–Smirnov ToE analysis outputs All analysis code used to generate the dataset and manuscript figures is available in the accompanying GitHub repository. These files support reproducibility of the analysis presented in the associated manuscript.