FY-4A卫星在宁夏短时强降水中的适用性研究

Application of FY-4A satellite data in short-time severe precipitation of Ningxia

通过收集2018—2020年宁夏短时强降水个例及其对应时段的FY-4A卫星资料,选取FY-4A卫星云类型CLT、云相态CLP、云顶高度CTH、对流层折叠最深深度TFTP_Z_depth、降水估计QPE等5类产品进行可用性分析。结果表明:(1)FY-4A数据接收率和物理保存情况,足以支持实时监测预警业务;(2)5类产品在宁夏短时强降水个例中有不同的表现,其中CLT、CLP具有较好的可用性,可以较好的判断云的类别;而CTH和QPE均存在较大误差且均为偏小趋势,需结合其他手段予以订正;CTT、TFTP_Z_depth两种产品与短时强降水的对应关系较为明显,而CTH高值有利于出现强降水,但并不是出现强降水的必要条件。整体来说,FY-4A卫星在宁夏短时强降水天气中具有一定可用性和参考性,可为对流性天气判别、人工影响天气作业提供较好的数据支持。

By using FY-4A satellite data and artificial observation data of recent(2018-2020)severe precipitation cases in Ningxia,four different FY-4A satellite product types are examined in terms of their availability.Results show that:(1)The data transmission rate and physical preservation of FY-4A are sufficient to support real-time monitoring and early warning services;(2)The five kinds of products i.e.,Cloud Type(CLT),Cloud Phase(CLP),Cloud Top Height(CTH),Quantitative Rainfall-Rate Estimation(QPE),and Tropopause Folding Depth(TFTP_Z_depth),have different performances in the case of severe convective weathers in Ningxia.Among them,CLT and CLP have good availability,making it possible to determine the type of cloud more accurately.However,both CTH and QPE have large errors and tend to be smaller,so they need to be revised in conjunction with other means.The relationship between CTT or TFTP_Z_depth products and recent severe precipitation is obvious.The high value of CTH is conducive to the occurrence of heavy precipitation but is not a necessary condition.Overall,the FY-4A satellite has certain usability and reference in severe convective weather in Ningxia,which can provide better data support for convective weather discrimination and artificial influence on weather operation.