Evaluating clear-sky assimilation of FengYun-3E microwave radiance data in predicting multiple tropical cyclones over the Western North Pacific

Abstract

Since the successful launch and operation of the FengYun-3E (FY-3E) satellite, the assessment of its data quality and applications has garnered significant attention. By comparison with previous studies focusing on the assessment on a single case, this research assimilates the Microwave Humidity Sounder-2 (MWHS-2) and the Microwave Temperature Sounder-3 (MWTS-3) data to evaluate the track and intensity prediction of 19 tropical cyclones (TCs) over the western North Pacific (WNP). This comprehensive investigation seeks to unravel the contributions of microwave radiance onboard FY-3E to the initial fields in the multi-typhoon predictions. For each TC case, three experiments are carried out to evaluate the effect of microwave radiance data on clear-sky assimilation: the control experiment (CONV) assimilates only conventional data, while the other two experiments incorporate MWHS-2 (MWHS) and MWTS-3 (MWTS) data, respectively. The results indicate that MWHS and MWTS exert distinct effects on dynamical and thermodynamic variables across various atmospheric levels. The positive impact of MWHS and MWTS on the track and intensity forecast has been proven, respectively, with the root mean square errors reduced by 3.86 % for track, 4.76 % for maximum wind speed (MWS), and 7.78 % for minimum surface level pressure (MSLP) relative to CONV. For the three-day average forecast errors, the MWHS exhibits the lowest daily mean track error, while the MWTS primarily contributes to reducing the MSLP error on the second day and the MWS error on the first and third days.