A daily dataset of global marine heatwaves from 1982 to 2020

Marine heatwave (MHW) is prolonged high‑temperature extreme events in the ocean, which can cause devastating impacts to marine life, and then has a serious impact on the climate system and the social economy. Based on the global daily remotely sensed National Oceanic and Atmospheric Administration (NOAA) Optimum Interpolation (OI) SST V2 high resolution (1/4°) gridded SST data over 1982–2020, and with reference to previous studies on marine heatwaves, MHW is defined as the period when SSTs exceed the 90th percentile (threshold value) of the 30-year historical reference period (1983-2012) for at least five consecutive days. The dataset presents the daily intensity of global MHWs from 1982 to 2020, which is stored in NETCDF format with a horizontal resolution of 0.25°×0.25° and a time step of day, and for the period without MHWs, the data is stored as 0. The data product can be used as a basic data to study the seasonal to decadal changes of the ocean extreme events and explore the effects of global warming on the surface layer of oceans in recent 40 years.