Development of a Real-time Near-surface Air Temperature, Humidity, and Wind Product with 10-min Resolution in China

In recent years, the frequent occurrence of catastrophic extreme weather events has led to an increasing demand for meteorological analysis products that offer high temporal and spatial resolution as well as quality. National Meteorological Information Center (NMIC), on the basis of operational analysis products of 1-h resolution near-surface temperature, relative humidity and wind in China, eliminates abnormal values of observations from ground stations through the minute-level quality control technology, and resamples 10-min resolution background data from the near-surface model forecast data using spatio-temporal downscale analysis techniques. After estimating changes in air temperature caused by different heights through topographic data, biases of the near-surface temperature background data can be removed, and a real-time analysis system is constructed when parameters of the fusion analysis for air temperature, relative humidity and wind in China are optimized, which produce 10-min products since 2020 with time limit of 5 min. In product assessment, 4320 times of products in November 2020 are selected and evaluated using the national ground observatory, showing that the quality of 10-min product is comparable to that of 1-h product with error metrics of correlation coefficient, the mean error and the root mean square error (RMSE) are basically close to each other, and RMSE values of 10-min product for air temperature, relative humidity and wind are 1.5 ℃, 7.0% and 1.3 m·s^-1 respectively, which are significantly better than those of the background field from model forecasts. At the same time, 3 application cases of 10-min products are shown, including the cold wave event in March 2025, the strong convective gale process in Tongzhou, Beijing in 2022 and the cyclone in Kaiyuan, Liaoning in 2023. Results indicate that these near-surface air temperature, relative humidity and wind in 10-min product can more finely characterize the process of these extreme weather events when compared with 1-h products, which improve the capability of meteorological operations from hourly to minutely level. At present, 10-min product is being utilized by the national and provincial meteorological departments for real-time operations.