The National Aeronautics and Space Administration‐Japan Aerospace Exploration Agency Global Precipitation Measurement (GPM) mission consists of a multisatellite constellation that provides real‐time or near‐real‐time global observations of rain and snow. In this study, GPM Level 3 Integrated Multi‐satellitE Retrievals for GPM (IMERG) and Level 2 GPM Microwave Imager Goddard Profiling rainfall products have been assimilated into the Weather Research and Forecasting model using the community Gridpoint Statistical Interpolation (GSI) data assimilation system. Experiments have been conducted and compared to demonstrate the impact of rain rate data assimilation on forecasts of heavy rainfall related to Hurricane Harvey (2017) and moderate to light rainfall observed during the GPM Integrated Precipitation and Hydrology Experiment field campaign. The results indicate that both GPM Microwave Imager Goddard Profiling and IMERG data could generate apparent increments in moisture, temperature, wind, and pressure fields for Hurricane Harvey, which led to significant improvement in the precipitation forecast. Frequent (every 3 hr) assimilation of IMERG data also positively impacted the short‐term precipitation forecast skill for the Integrated Precipitation and Hydrology Experiment moderate to light rain events. However, results also indicate that the impact of rain data assimilation was limited for a system that had a small horizontal dimension with low rain rates and within a relatively stable synoptic environment.

中文翻译：

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利用GSI数据同化系统对GPM雨量产品进行同化，以处理重度和轻度降水事件

日本国家航空航天局-日本航空航天探索局全球降水测量（GPM）任务由一个多卫星星座组成，可提供实时或近实时的全球雨雪观测。在本研究中，已使用社区网格点统计插值（GSI）数据同化系统将GPM的GPM 3级综合多卫星检索（IMERG）和2级GPM微波成像仪Goddard分析降雨产品同化为天气研究和预报模型。进行了实验并进行了比较，以证明雨量数据同化对GPM综合降水与水文学实验野外活动期间观测到的与哈维（2017）飓风有关的强降雨和中小雨预报的影响。结果表明，GPM微波成像仪Goddard分析和IMERG数据都可以为哈维飓风产生明显的湿度，温度，风和压力场增量，从而使降水预报显着改善。IMERG数据的频繁（每3小时）同化也对中度至小雨事件的综合降水与水文学实验的短期降水预报技能产生积极影响。但是，结果还表明，对于水平尺寸较小，降雨率较低且在相对稳定的天气环境下的系统，降雨数据同化的影响是有限的。和哈维飓风的压力场，导致降水预报显着改善。IMERG数据的频繁（每3小时）同化也对中度至小雨事件的综合降水与水文学实验的短期降水预报技能产生积极影响。但是，结果还表明，对于水平尺寸较小，降雨率较低且在相对稳定的天气环境下的系统，降雨数据同化的影响是有限的。和哈维飓风的压力场，导致降水预报显着改善。IMERG数据的频繁（每3小时）同化也对中度至小雨事件的综合降水与水文学实验的短期降水预报技能产生积极影响。但是，结果还表明，对于水平尺寸较小，降雨率较低且在相对稳定的天气环境下的系统，降雨数据同化的影响是有限的。