Application Experiment of Assimilating Beidou Satellite Navigation Round-Trip Sounding Data Observed in Guangdong Province Using CMA-GD Model
ZHANG Chengzhong
HUANG Yanyan
LIANG Jiahao
XU Huangfei
Abstract：To reveal the quality of Beidou satellite navigation round-trip sounding data for the South China region and its impact on the CMA-GD model,the present study compared a one-month dataset of Beidou satellite navigation sounding observations with L-band sounding data and reanalysis data from the European Centre for Medium-Range Weather Forecasts(ECMWF).The results show that the root mean squared errors(RMSE)between Beidou satellite navigation data and L-band sounding data were less than 1 m·s-1 for wind speed,less than 1℃ for temperature,and less than 10％for relative humidity.The standard deviation of observed wind speed from Beidou sounding data was less than 2 m·s-1 in the troposphere,and the observed temperature was～1 K lower than corresponding ECMWF reanalysis data.The observed humidity in the atmosphere was 5％dryer near 200 hPa,while,in other layers,it was 5％～15％wetter than corresponding ECMWF reanalysis data.The standard deviations of each variable(wind,temperature,and humidity)above the troposphere were greater than those of the troposphere.Case studies of a cold air intrusion event and a typhoon landfall process reveal that the assimilation of Beidou navigation sounding data yielded comparable results to the assimilation of L-band data in terms of precipitation prediction scores(TS).Notably,the 24-hour typhoon track forecast improved by 32％when using Beidou navigation data,demonstrating that the assimilation of round-trip sounding data has a neutral to positive impact on short-term precipitation and typhoon track forecasts compared to the assimilation of L-band ascent-only data.
Keywords：Beidou satellite navigation soundingdata assimilation experimentcase studySouth China region
Publication Date：2025-02-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：10( 16-25 )