Atmospheric reanalysis data play a critical role in a wide range of meteorological applications, such as weather and climate studies, assessment of meteorological resources, and artificial intelligence-driven forecasting. The China Meteorological Administration (CMA) Regional Re-Analysis version 1.0 (CMA-RRA v1.0) system, developed using the CMA mesoscale (CMA-MESO) model and its three-dimensional variational (3DVAR) data assimilation system, aims to generate long-term, high-resolution 3D atmospheric fields. This paper describes the processing framework of the CMA-RRA v1.0 system and reports on the development of a regional reanalysis dataset (2010–2024) produced by the system. The dataset covers the entire China region with a 3-km horizontal resolution, 70 sigma levels, and a 1-h temporal resolution. High-density local observations are assimilated during the reanalysis process, including automatic surface weather observations, reflectivity and radial velocity data from the CMA weather radar network, and data from Fengyun series satellites. Compared with observations and the global ECMWF reanalysis version 5 (ERA5), CMA-RRA v1.0 demonstrates superior performance. It shows closer agreement with radiosonde observations and yields higher equitable threat scores for precipitation at all intensity levels. Furthermore, the probability density distribution of CMA-RRA v1.0 precipitation aligns more closely with observations. Owing to its high resolution and assimilation of denser local data, CMA-RRA v1.0 also accurately reproduces historical high-impact weather events, such as the 3–4 May 2017 squall line, Typhoon Lekima (2019), and the July 2023 extreme rainfall in North China.

To assess the application potential of the ascent–drift–descent radiosonde system (ADDRS) data over China, and to provide reference for the receiving station deployment, scenario projections for nationwide ADDRS network observations are conducted by using trajectory simulation data from the ADDRS trajectory prediction system. Based on the Beidou Sounding System of China, this study investigates the spatial distribution of descent-phase landing points of the ADDRS. The distances, azimuths, and seasonal variations of landing points relative to sounding stations are analyzed, together with the frequency of cross-border landings near border regions. In addition, the frequency distribution characteristics of landing points are examined, and a priority index for the deployment of additional receiving stations is proposed in conjunction with existing receiving station coverage. The results show that ADDRS landing points can nearly cover all land areas of China. In winter, the drifting distance of landing points relative to the sounding stations increases with latitude, reaching up to 1400 km, with landing points at high-latitude stations being more dispersed. During summer, the drifting distance decreases with latitude, and the landing points for low-latitude stations are more concentrated. The azimuth of landing points follows the prevailing wind direction in the stratosphere, exhibiting an east–west orientation, with distinct seasonal variations. The priority index for receiving station deployment suggests that approximately 443 receiving stations are needed to cover the entire region of China, enabling simultaneous ADDRS operations at all sounding stations nationwide.