基于红外亮温法的对流云云顶高度反演研究

Research on Inversion of Convective Cloud Top Height Based on Infrared Brightness Temperature Method

基于Himawari-8的可见光和红外扫描辐射计(AHI)数据,采用红外亮温法对2019年6~8月目标区域(20°N~30°N,100°E~120°E)的对流云云顶高度进行了计算。首先通过阈值法挑选出对流云区;然后基于红外亮温法,利用Himawari-8的11.2μm通道数据与ERA5再分析资料中的温度气压层数据进行了云顶高度反演;最后将反演云顶高度H与全球降水观测计划(Global Precipitation Measurement,GPM)产品数据进行了对比。结果显示,基于红外亮温法的Himawari-8数据反演对流云云顶高度与GPM产品数据一致,具有很好的相关性。相关系数为0.9,均方根偏差为0.29,平均偏差为0.48,纬向的离散分布优于经向,具有较强的适用性。

The AHI data of Himawari-8 and the infrared brightness temperature method are used to calculate the height of convective cloud tops in the 20°N--30°N and 100°E--120°E regions from June to August in 2019.Firstly,the convective cloud region is selected by threshold method.Then,based on the infrared brightness temperature method,the cloud top height is retrieved using the 11.2μm channel data of Himawari-8 and the temperature pressure layer data of ERA5 reanalysis data.Finally,the retrieved cloud top height is compared with the product data of GPM.The results show that the convective cloud top heights inverted from the Himawari-8 data by the infrared brightness temperature method are consistent with the GPM product data,and have a good correlation.The correlation coefficient is 0.9,RMSD is 0.29,and the mean deviation is 0.48.The discrete distribution of the latitudinal direction is better than that of the meridional direction,which has strong applicability.