Earth-China: Science and AI-enabled digital twin of regional earth system

China Sea (CS) consists of South China Sea, East China Sea, Yellow Sea and Bohai Sea. CS connects with terrestrial input from landside and with Western Pacific Ocean (WPC) fluxes from seaside. A healthy, resilient and predictable CS is important to sustainable socioeconomic development in the region and is largely determined by the sustainability of the interlinked spheres that compose the regional earth system (RES), including the lithosphere (land), the hydrosphere (oceans and rivers), the atmosphere, and the biosphere (living things). Based on an unprecedented holistic study of the interactions among natural forcings, human activities, and climate change using an integrated system to create an RES framework (https://earthhk.hkust.edu.hk/), we integrate science, AI and develop a digital twin of the regional earth system that integrates streaming data from observations, an earth simulator of land-ocean-atmosphere and an immersive and interactive visual interface for diagnosis and prognosis in the CS and WPC.