Although radar observations capture storm structures with high spatiotemporal resolutions, they are limited within the storm region after the precipitation formed. Geostationary satellites data cover the gaps in the radar network prior to the formation of the precipitation for the storms and their environment. The study explores the effects of assimilating the water vapor channel radiances from Himawari-8 data with Weather Research and Forecasting model data assimilation system (WRFDA) for a severe storm case over north China. A fast cloud detection scheme for Advanced Himawari imager (AHI) radiance is enhanced in the framework of the WRFDA system initially in this study. The bias corrections, the cloud detection for the clear-sky AHI radiance, and the observation error modeling for cloudy radiance are conducted before the data assimilation. All AHI radiance observations are fully applied without any quality control for all-sky AHI radiance data assimilation. Results show that the simulated all-sky AHI radiance fits the observations better by using the cloud dependent observation error model, further improving the cloud heights. The all-sky AHI radiance assimilation adjusts all types of hydrometeor variables, especially cloud water and precipitation snow. It is proven that assimilating all-sky AHI data improves hydrometeor specifications when verified against the radar reflectivity. Consequently, the assimilation of AHI observations under the all-sky condition has an overall improved impact on both the precipitation locations and intensity compared to the experiment with only conventional and AHI clear-sky radiance data.

尽管雷达观测以高时空分辨率捕获了暴风雨结构，但在降水形成后，它们仅限于暴风雨区域内。对地静止卫星数据覆盖了风暴和周围环境降水形成之前雷达网络中的空白。该研究探索了使用Himawari-8数据与天气研究和预报模型数据同化系统（WRFDA）融合从Himawari-8数据中吸收水汽通道辐射的效果，该辐射对华北地区发生了严重的暴雨。这项研究最初在WRFDA系统的框架中增强了用于高级Himawari成像仪（AHI）辐射的快速云检测方案。在进行数据同化之前，先进行偏差校正，晴空AHI辐射的云探测和多云辐射的观测误差建模。完全应用了所有AHI辐射观测值，而没有对全天候AHI辐射数据同化进行任何质量控制。结果表明，通过使用依赖于云的观测误差模型，模拟的全天空AHI辐射度更适合观测，从而进一步提高了云的高度。全天候的AHI辐射同化会调整所有类型的水凝物变量，尤其是云水和降水雪。事实证明，通过对雷达反射率进行验证，吸收全天候AHI数据可以改善水凝物规格。因此，与仅使用常规和AHI晴朗天空辐射率数据的实验相比，在全天条件下对AHI观测值的同化对降水位置和强度都有整体改善的影响。