Abstract A 43-year Climate Data Record (CDR) of combined global sea and sea-ice surface temperature (SST/IST) from 1982 to 2024 has been produced from satellite observations within the Copernicus Climate Change Service (C3S). Infrared and microwave satellite data are integrated using optimal interpolation to provide daily, gap-free (L4, 0.05 ° ) global SST/IST fields. Consistent and accurate sea-ice concentration (SIC) fields are derived by combining passive microwave SIC CDRs with sea ice charts, improving SST and IST characterization. The product also includes under-ice SST (UISST) derived from SIC and monthly salinity climatologies. Validation against in situ SSTs shows median differences of −0.04 ° C and robust standard deviations of 0.17–0.28 ° C. For sea ice, the median differences range from 1.41 ° C to − 4.62 ° C, with robust standard deviations of 2.55–4.99 ∘C. This CDR provides a novel and consistent dataset for assessing climate change and extremes in polar regions and globally, independently of sea-ice cover. From 1982–2024, global SST/IST increased by ~0.75 ° C, with amplified Arctic warming (~4.36 ° C) and modest Antarctic warming ~0.54 ° C), although recent years have been record-breakingly warm in Antarctica.
Englyst et al. (Fri,) studied this question.