Development of a next-generation regional climate scenario system toward IPCC AR7 for East Asia

In preparation for the IPCC Seventh Assessment Report (AR7), this study presents a high-resolution regional climate scenario framework for East Asia that incorporates the latest scientific advances and policy demands. The framework, referred to as EAS-11, employs the WRF version 4.4 regional climate model at a horizontal resolution of 12 km, offering four times finer detail than the preceding EAS-22 experiments. Ten ensemble members will be generated through combinations of two microphysics schemes (WSM6, P3), two cumulus parameterization schemes (MSKF, BMJ), two planetary boundary layer schemes (YSU, MYJ), and two coupled ocean atmosphere configurations using the COAWST system. The coupled model integrates WRF version 4.2.2 with ROMS 3.9. For the EAS-11 experiments, the K-ACE2 global model outputs will be used as the boundary forcing for both historical (1950 2021) and scenario (2022 2100) experiments based on six CMIP7 greenhouse gas emission pathways. The modeling domain aligns with the CORDEX-EA Phase 2 boundaries, with refined topography, 35 vertical layers, and spectral nudging to maintain large-scale circulation. The resulting dataset, approximately 1 PB in NetCDF4 format, includes more than 50 atmospheric and land-surface variables at temporal resolutions ranging from hourly to daily. The EAS-11 delivers a standardized and high-resolution climate dataset, providing a critical foundation for climate impact assessments, adaptation and mitigation strategies, and collaborative research across East Asia.