Application of Aeolus Horizontal Line-of-Sight Product Data Assimilation in Typhoon Forecasting

To evaluate the impact of spaceborne lidar product data assimilation on typhoon forecasts, this paper studied the assimilation of Aeolus horizontal line-of-sight data and its impact on typhoon forecasts for typhoon Hagupit occurred in 2020 and typhoon Lekima happened in 2019. First, we conducted a statistical test and deviation correction on Aeolus products and used the statistical root mean square error for each height layer as the observation error for the assimilation. Subsequently, Aeolus products were assimilated using the Weather Research and Forecast model data assimilation system (WRFDA), and the prediction test was conducted using the Weather Research and Forecast model (WRF). The experimental results show that Aeolus products are highly accurate, and the observation error for each layer after correction is in the range of 3–5 m/s, with the error increasing with altitude. The corrected data satisfy the unbiased assumption of three-dimensional variational assimilation. Assimilating Aeolus products during Typhoons Hagupit and Lekima can make the model show a more reasonable circulation pattern and effectively improve the typhoons’ track and intensity forecasts.