《海洋预报》| 葵花8号AHI晴空水汽辐射率资料同化对北上台风“巴威”的降水预报影响研究

摘要：为提升北上台风强降水的精细化预报水平，针对2020年8月的北上台风“巴威”，利用3 km分辨率的天气预报模式（WRF）及其三维变分同化（3D-Var）系统，研究静止气象卫星葵花8号成像仪（AHI）的3条水汽通道晴空辐射率资料不同同化频次对此次北上台风降水预报的

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单位：

1. 天津市海洋气象重点实验室天津市气象科学研究所, 天津 300074;

2. 中国气象局沈阳大气环境研究所, 辽宁沈阳 110166;

3. 天津市环境气象中心, 天津 300074

分类号：P457.8

出版年·卷·期（页码）：2025·42·第三期（76-91）

摘要：为提升北上台风强降水的精细化预报水平，针对2020年8月的北上台风“巴威”，利用3 km分辨率的天气预报模式（WRF）及其三维变分同化（3D-Var）系统，研究静止气象卫星葵花8号成像仪（AHI）的3条水汽通道晴空辐射率资料不同同化频次对此次北上台风降水预报的影响，并分析了1 h循环同化试验改善强降水的动力和热力原因。研究结果表明：循环同化AHI晴空水汽辐射率资料对台风中心最低气压及中心最大风速的前12 h预报均有改进作用；同化频次增加至1 h，台风中心最大风速预报改进明显。经技巧评分、公平技巧评分、真实技巧评分及命中率多种客观统计检验指标证实，同化AHI晴空水汽辐射率资料的试验对预报时效和降水阈值均有较好的预报技巧，且1 h循环同化试验对前24 h强降水预报优势最显著。循环同化AHI晴空水汽辐射率资料能改善对流层中上层的暖湿条件，1 h循环同化较3 h循环同化增强了低空急流及上升运动，进而提升了模式强降水预报能力。

关键词：AHI晴空水汽辐射率北上台风葵花8号静止气象卫星降水预报台风“巴威”

Abstract：To improve the heavy precipitation forecasts of northward-moving typhoons, taking Typhoon“Bavi”in August 2020 as an example, this work studies the influence of assimilation frequency of the clear-sky AHI water vapor radiance, collected by three water vapor channels on the Himawari-8 geostationary meteorological satellite, on the precipitation forecasts of Typhoon "Bavi" based on the Weather Research Forecast（WRF） model with a horizontal resolution of 3 km and Three-Dimensional Variational assimilation system（3D-Var）. The dynamical and thermodynamical mechanisms for the improved heavy precipitation forecasts in the hourly-cycle assimilation experiment are discussed. The results show that the cycle assimilation of the clear-sky AHI water vapor radiance improves the 12-hour forecasts of typhoon center minimum pressure and maximum wind speeds.The typhoon center maximum wind speed forecasts improve substantially when the assimilation frequency increases to 1 hour. A multiple of objective statistical scores including TS, ETS, TSS, and POD confirm that assimilating AHI clear-sky water vapor radiance produces better forecasting skills for both lead time and rainfall threshold. The hourly-cycle assimilation experiment has the best ability for 0～24 hours heavy precipitation forecasts. Cycling AHI clear-sky water vapor radiance assimilation greatly modifies the warm and humid conditions in the middle and upper troposphere. Compared to three hourly cycle assimilation experiment, the hourly cycle assimilation experiment further enhances the low-level jet and updraft, thus improving the forecasts of heavy precipitation.

Key words：AHI clear-sky water vapor radiance; northward-moving typhoon; geostationary meteorological satellite Himawari-8; precipitation forecasts; Typhoon "Bavi"