Arid Zone Research ›› 2025, Vol. 42 ›› Issue (10): 1777-1790.doi: 10.13866/j.azr.2025.10.03

• Weather and Climate • Previous Articles     Next Articles

Capability and biases of satellite precipitation products in monitoring extreme rainstorms along the northern slope of the Kunlun Mountains

YU Zhixiang1(), YANG Xia2(), YU Xiaojing3, JIANG Xutao3   

  1. 1. Urumqi Meteorological Satellite Ground Station, Urumqi 830011, Xinjiang, China
    2. Xinjiang Uygur Autonomous Region Meteorological Observatory, Urumqi 830002, Xinjiang, China
    3. College of Geography and Remote Sensing Sciences, Xinjiang University, Urumqi 830017, Xinjiang, China
  • Received:2025-04-09 Revised:2025-06-25 Online:2025-10-15 Published:2025-10-22
  • Contact: YANG Xia E-mail:yzxwxz@126.com;yangxia921@163.com

Abstract:

The northern slope of the Kunlun Mountains is characterized by complex topography, extreme rainstorms, and an uneven distribution of meteorological stations, making it challenging to accurately capture the fine-scale spatial distribution and temporal evolution of extreme rainstorms using conventional, ground-based observations. Satellite precipitation products for monitoring rainstorms not only effectively fill the regional gap but also improve the capability of monitoring and early warning for severe catastrophic weather. On the basis of hourly precipitation data from 383 meteorological stations and eight sets of satellite precipitation products over the northern slope of the Kunlun Mountains, we selected three representative extreme rainstorm processes to comprehensively assess the applicability of eight satellite precipitation products for monitoring extreme precipitation events and quantitatively analyze their performance on the northern slope of the Kunlun Mountains. The results were as follows: (1) The GPM IMERG Early, GPM IMERG Late, and GPM IMERG Final products showed good performance in capturing the spatial distribution and magnitude of extreme precipitation, with hit rates exceeding 99%. Among them, the GPM IMERG Final product had the best performance, with a correlation coefficient of 0.64 between ground-observed precipitation and the GPM IMERG Final product during Event 3. The FY2H and FY4A precipitation products showed certain discrepancies in comparison with ground observations in both qualitative and quantitative evaluations, with low correlation coefficients (below 0.01). (2) In terms of temporal evolution characteristics of extreme precipitation processes, all satellite precipitation products showed certain biases, ranging from -95% to 250%. In comparison with the other satellite products, the GPM IMERG Final product outperformed in terms of precipitation amounts at each time step and temporal trends, with accuracy and threat score values above 0.8. (3) The spatial extent of the three extreme rainstorms reproduced by eight satellite precipitation products was smaller than that indicated by observations, and the intensity was weaker, with obvious underestimation characteristics. The missing detection bias generally accounted for more than 50% of the relative contribution rate of errors, which is one of the main reasons for the underestimation of extreme heavy precipitation events by satellite precipitation products. Overall, satellite precipitation products reflected the extreme precipitation processes on the northern slope of the Kunlun Mountains to a certain extent, but their accuracy in monitoring requires further improvement. These results provide a scientific basis for selecting appropriate satellite precipitation products for regional applications and offer data support for bias correction, algorithm optimization, and improved monitoring of extreme precipitation in this region.

Key words: northern slope of the Kunlun Mountains, extreme rainstorms, satellite precipitation products, monitoring, evaluation