Application of M5 Model Tree in Passive Remote Sensing of Thin Ice Cloud Microphysical Properties in Terahertz Region

This article presents a new method for retrieving the Ice Water Path (IWP), median volume equivalent sphere diameter (Dme) of thin ice clouds (IWP < 100 g/m2, Dme 80 μm) in Terahertz band. The upwelling brightness temperature depressions caused by at 325.15, 448.0, 664.0 and 874.0 GHz channels are simulated Atmospheric Radiative Transfer Simulator (ARTS). forward radiative transfer models taken as historical data M5 model tree algorithm to construct set piecewise functions which represent relation IWP. inversion results optimized an empirical IWP is summarized previous studies. We inverse with analyze performance selected channels. 874.4 ± 6.0 channel provides most accurate results, because strong response change model. In order improve retrieval accuracy middle-high frequency band, dual-channel was proposed that combines 448.0± 3.0 4.2 channel. error analysis shows reliable, meet requirement range