Abstract The new generation of geostationary environmental operational satellite imager, the Himawari-8 Advanced Himawari Imager (AHI), adds two more water vapour channels and four more other channels than its predecessor, MTSAT-2. But except for the three water vapour channels, AHI channels are often not assimilated over land due to large uncertainty in surface parameters. Using the relative adjoint sensitivity analysis method, we show that the brightness temperature of AHI channel 16 is much more sensitive to the low-tropospheric atmosphere than to the surface emissivity, similar to those high-level water vapour channels. We thus assimilated AHI channel 16 brightness temperature observations together with AHI water vapour channels over land, and assessed the added benefits on short-range quantitative precipitation forecasts for several convection-induced rainfall cases. Results show that adding channel 16 over land to AHI data assimilation further improves short-range rainfall forecasts. Assimilation of AHI channel 16 improves the upstream near surface atmospheric temperature analysis and influences the development of downstream precipitating weather systems.

中文翻译：

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在陆地上的 AHI 数据同化中添加 CO2 通道 16 进一步改进了短期降雨预报

摘要 新一代地球静止环境业务卫星成像仪 Himawari-8 Advanced Himawari Imager (AHI) 比其前身 MTSAT-2 增加了两个水汽通道和四个其他通道。但除了三个水汽通道外，由于地表参数存在很大的不确定性，AHI 通道通常不会在陆地上同化。使用相对伴随敏感性分析方法，我们表明AHI通道16的亮温对低对流层大气比对地表发射率敏感得多，类似于那些高层水汽通道。因此，我们同化了 AHI 通道 16 的亮温观测数据以及陆地上的 AHI 水汽通道，并评估了对几种对流引起的降雨情况的短期定量降水预报的额外好处。结果表明，将陆地上的 16 频道添加到 AHI 数据同化中进一步改进了短期降雨预报。AHI 通道 16 的同化改善了上游近地表大气温度分析并影响下游降水天气系统的发展。