The CMA-CW v1.0 Atmospheric Chemistry Rapid Cycle System Forecast Performance Assessment

In order to fully understand the performance of the CMA-CW v1.0 rapid cycle system, continuous cycle tests were conducted for one month each in winter and summer. The results of the 72-hour forecasts at 00 UTC (Coordinated Universal Time) each day were assessed,, and the conclusions are as follows: (1) The CMA-CW v1.0 rapid update cycle system possesses the capability to efficiently assimilate ground-based aerosol observation data. (2) Incorporating aerosol observations into the December 2023 experiment significantly improved the accuracy of PM2.5 mass concentration analysis. (3) The PM2.5 forecast accuracy within 24 hours after aerosol assimilation in December 2023 showed a marked increase, indicating that aerosol assimilation enhances the forecasting capability of pollutant concentrations. (4) Regarding impacts on weather element forecasts: Winter experiment (December 2023): Aerosol cycle assimilation positively contributed to light rain precipitation forecasts. Summer precipitation experiment (July 2025): Aerosol cycle assimilation positively contributed to forecasts of all precipitation levels within 24 hours. Aerosol assimilation had minor effects on 2-meter temperature and 10-meter wind forecast.