Land Surface Temperature Retrieval from the Infrared Measurements of Advanced Himawari Imager on Himawari-8

This work addresses Land Surface Temperature (LST) retrieval from the infrared measurements of Advanced Himawari Imager (AHI) on Himawari-8 satellite using the Generalized Split-Window (GSW) algorithm. First, a radiative transfer modeling experiment is conducted using the moderate spectral resolution atmospheric transmittance algorithm and computer model (MODTRAN) 4.0 fed with the SeeBor V5.0 atmospheric profile database to simulate the brightness temperatures in the AHI channels 14 (centered at about 11.2 μm) and 15 (centered at about 12.3 μm) related to Land Surface Emissivities (LSEs) and Total Precipitable Water (TPW). Then, the unknown coefficients of the GSW algorithm are obtained through multi-variable linear regression, in which the simulated data are grouped into several sub-ranges to improve algorithm accuracy. Next, LSTs are derived from the clear-sky AHI measurements in September 2016 over a study area with longitude from 100°E to 145°E and latitude from 15°N to 45°N, where LSEs are deduced from the MOD11C1 V6 product using the baseline fit method, and TPWs are extracted from the European Centre for Medium-range Weather Forecasts (ECMWF) reanalysis data. Finally, the derived LSTs are cross-validated with the MOD11C1 V6 product. The results show that the GSW algorithm developed in this work can accurately retrieve LST from the AHI measurements, and the error is 0.39±1.62 K against the MOD11C1 V6 product.