Atmospheric reanalysis is a process that utilizes numerical weather prediction (NWP) models and data assimilation systems to integrate historical meteorological observations, thereby reconstructing datasets that represent past atmospheric states. This paper presents the China Meteorological Administration’s (CMA) latest global atmospheric reanalysis product, CRA1.5, which employs the Global Spectral Model (GSM) and the Gridpoint Statistical Interpolation (GSI) Data Assimilation system. CRA1.5 features a model spectral resolution of TL1534 (equivalent to approximately 13 km in horizontal grid spacing), a product time interval of 1 h, a model top at 0.27 hPa, and a hybrid-4DEnVar scheme along with an Ensemble Kalman Filter for data assimilation. The temporal coverage of CRA1.5 extends from 1979 to near real-time. During the reanalysis production, we assimilated a substantial volume of reprocessed satellite data and extensive conventional observations. These observations include dense networks of conventional observations within China (comprising approximately 120 sounding stations and 2400 meteorological stations) as well as satellite observations from China’s Fengyun, Haiyang, and Yunyao satellite series. Compared to CRA-40, the root-mean-square error (RMSE) of geopotential height at 500 hPa is reduced by 22.46%, the RMSE of temperature at 200 hPa is reduced by 21.7%, and the RMSE of zonal wind at 850 hPa is reduced by 14.41%. CRA1.5 outperforms ERA5 in 100-m wind speed over China (RMSE: 3.21–3.36 m s−1 vs. 3.46–3.59 m s−1) and achieves comparable accuracy to ERA5 in atmospheric precipitable water (RMSE: 3.10 mm vs. 3.13 mm). CRA1.5’s 2-m temperature trend aligns closely with HadCRUT5, capturing global warming accurately. With higher spatiotemporal resolution (0.1° × 0.1°, hourly) and advanced assimilation, CRA1.5 provides a critical dataset for climate monitoring, NWP, and AI-based meteorological research. CRA1.5 has been implemented for real-time operation at the CMA. Updates are available up to 6 h after the analysis time, with a final update provided at a 3-day lag.
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To meet the need for weather forecasting, strong convection monitoring and warning services, an hourly 1 km wind gust product across China has been produced using hourly wind gust observations and model forecast data. These data are adopted after the procedure of quality control, space-time matching and fusion analysis. This product is updated at a 5 min lag with the overall RMSEs of 1.9 m/s for independent test and 0.68 m/s for the non-independent test. The results indicate that as the wind speed increases, the number of samples continuously declines, there is a relatively pronounced tendency for the product's error to rise, and the accuracy gradually decreases. However, the quality of this product improves effectively compared to model predictions of high speed of wind gusts. Specifically, the accuracy of wind speed above magnitude 9 has improved by 89.3%, and the relative error has dropped significantly with a reduction ratio of about 27.4%. The development of this product can support disaster mitigation and decision-making related to catastrophic gales and typhoons.
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