Arid Zone Research ›› 2025, Vol. 42 ›› Issue (6): 957-969.doi: 10.13866/j.azr.2025.06.01

• Weather and Climate • Previous Articles     Next Articles

Precipitation retrieval for Xinjiang region based on radar and remote sensing satellites

GUO Jianmao1(), WU Dengguo1, HAN Jinlong1, ZHANG Rushui1, WANG Yong2()   

  1. 1. School of Ecology and Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, China
    2. Urumqi Meteorological Satellite Ground Station, Urumqi 830011, Xinjiang, China
  • Received:2024-12-23 Revised:2025-03-11 Online:2025-06-15 Published:2025-06-11
  • Contact: WANG Yong E-mail:18951992585@163.com;qfwy721@sina.com

Abstract:

To more accurately obtain precipitation distributions in remote areas, this study combined the high-resolution advantages of radar and the wide-coverage detection of satellites. By integrating radar and satellite-derived precipitation, we generated high-precision quantitative precipitation estimation products. Using the strong convective events in Xinjiang on August 12 and 13, 2023, as an example, we used radar reflectivity for precipitation inversion based on cloud classification and Z-R relationships. We fed the Himawari 9 satellite brightness temperature and IMERG precipitation into a BP neural network model to establish the relationship between the average brightness temperature and the average rainfall intensity. Subsequently, we used the instantaneous brightness temperature of the Himawari 9 satellite to invert the momentary precipitation through the BP neural network model. We also proposed two precipitation data fusion schemes: Scheme I uses a uniform correction value to integrate radar and satellite precipitation, whereas Scheme Ⅱ further considers the precipitation intensity levels for comparison. Finally, we obtained high-precision precipitation inversion products for Xinjiang. The results showed that: (1) Cloud classification based on brightness temperature can finely estimate precipitation within the radar range, and brightness temperature differences can reduce the impact of non-precipitating clouds to some extent. (2) The root mean square error (RMSE) of the satellite precipitation inversion was 1.793 mm·h-1, with a coefficient of determination (R2) of 0.572, indicating reasonable model accuracy. The binary classification score indicated that the model can accurately invert precipitation in over 70% of the areas. (3) The fusion of precipitation by the two schemes slightly improved the accuracy of short-duration light rain distributions. Scheme Ⅱ outperformed Scheme I for short-duration moderate rain but showed a slight decline for short-duration heavy rain compared with Scheme I, indicating that the asynchrony between satellite observation and near-surface precipitation had some impact. (4) Under a 95% confidence interval, the P-values for the RMSE and R2 differences between the two schemes and satellite inversion were all less than 0.005, while the P-value for Scheme Ⅱ compared with Scheme I was greater than 0.05. Both fusion schemes significantly improved the accuracy of the satellite precipitation; however, the improvement of Scheme Ⅱ, which considers the precipitation intensity levels, over Scheme I was minimal.

Key words: multi-radar, Himawari 9 satellite, brightness temperature, precipitation retrieval, BP neural network, precipitation data fusion, Xinjiang