Advances in China’s Ocean Satellite Observation System Since 2024

Since 2024, China’s ocean satellite program has made systematic progress in the construction of observation systems, expansion of mission portfolios, enhancement of ground-support capabilities, product development, and intelligent applications. An ocean satellite observation system composed of ocean color satellites, ocean dynamic satellites, and ocean surveillance and monitoring satellites has been initially established, providing multi-satellite coordinated observation capabilities over China’s coastal seas, the global ocean, and polar regions. The successful launch of HY-4A has filled a gap in China’s spaceborne ocean salinity observation capability and provided a foundational capacity for operational global ocean salinity monitoring and related scientific research. The stable operation of ground receiving systems, calibration and validation sites, and data-sharing infrastructure has provided reliable support for networked ocean satellite observations and operational applications. The upgrading of the ocean color satellite data processing system, the development of application-ready products for the Yellow Sea and East China Sea, and the generation of multi-parameter polar sea-ice products indicate that China’s ocean satellite product system is evolving from basic data provision toward thematic, refined, and operational applications. The development of artificial intelligence foundation models represented by “SkyOcean” further suggests that ocean satellite applications are extending from two-dimensional sea-surface observations toward three-dimensional environmental reconstruction and prediction services.