Evaluation of FY-4A Cloud Top Temperature Product Based on L-Band Radiosonde Data and Its Application in Winter Precipitation Type Identification
By using the L-band radiosonde data of Shanghai Baoshan Station during the winter from 2019 to 2021,the FY-4A cloud top temperature(CTT)product is evaluated.The results indicate that the CTT of the single-layer cloud can be reflected well by the FY-4A CTT product,while the CTT of multi-layer clouds is generally overestimated with the mean bias larger than 14℃.And the FY-4A CTT product has a small mean bias of approximately 3 ℃ compared to the sounding observation when the observed cloud top height is below 6 km or the observed cloud top temperature is higher than-20℃.Moreover,based on the surface observation in the Yangtze River Delta Region in the winter of 2021 and 2022,the relationship be-tween CTT and precipitation types in winter seasons is statistically analyzed and further verified by typical cases.The results reveal that a low CTT is one of the main necessary conditions for snowfall,as most snowfall events occur when the CTT is below-12℃.As the FY-4A CTT product has a certain accuracy with a high spatial and temporal resolution,this product could have great application potential in iden-tifying precipitation types.
second-level radiosonde dataFY-4Acloud top temperature(CTT)productprecipitation typewinter
万方数据
维普
