利用分裂窗直方图法对半透明云云顶高度的反演研究

针对2016年4 — 9月90°—140°E, 15°—55°N区域的半透明云, 使用分裂窗直方图法, 利用Himawari-8的AHI观测数据进行云顶高度反演。首先使用阈值法筛选出半透明云区; 然后基于分裂窗直方图法, 利用Himawari-8的10.4 μm 和12.4 μm两个分裂窗通道数据以及ERA-Interim再分析资料中的温度气压层数据和位势高度气压层数据反演云顶高度, 并将反演结果与CloudSat的2B-GEOPROF产品数据进行匹配和对比, 结果表明: 1) 分裂窗直方图法对 Himawari-8数据反演半透明云云顶高度的结果与CloudSat的数据结果较一致, 均方根偏差为1.45 km; 2) 海陆类型对反演结果没有明显的影响。所提算法有较强的适用性, 可以应用于不同卫星的分裂窗通道数据反演, 特别是对中国新一代静止气象卫星风云四号的业务反演有理论参考价值。

Retrieval of Semi-transparent Cloud Top Height Using SplitWindow Histograms Method

The split window histograms method was applied to retrieve the cloud top height of semi-transparentclouds in the area of 90°?140°E, 15°?55°N using the AHI data on board Himawari-8 from April 1 to September 30in 2016. A threshold technique was used to screen the pixels of semi-transparent clouds. The cloud top heights ofthe pixels were retrieved by using the data of 10.4 ?m and 12.4 ?m split window channels of Himawari-8, and thedata of temperature and geopotential on pressure levels from ERA-Interim reanalysis. The retrieved cloud topheight was compared with the matched data of CloudSat. It is found that the split window histograms methodworks well, and the root mean square error of the result is 1.45 km, and the type of land or sea has no significantimpact on the result. The method has strong applicability and can be used to the split window channels of differentsatellites, especially for the theoretical algorithm of FY-4, a new generation of geostationary meteorologicalsatellite in China.