EXTENSION OF THE GENERALIZED SPLIT-WINDOW ALGORITHM FOR LAND SURFACE TEMPERATURE RETRIEVAL TO ATMOSPHERES WITH AIR TEMPERATURE INVERSION

This paper aims to extend the generalized split-window (GSW) algorithm in land surface temperature (LST) retrieval to atmospheres with air temperature inversion (ATI) near the Earth surface boundary. Simulation analysis shows that the influence of ATI on the LST retrieval of the GSW algorithm becomes larger when the ATI intensity increases. To further analyze the influence, all ATI atmospheric profiles are extracted from the Thermodynamic Initial Guess Retrieval (TIGR) cloud-free database. Combining the ATI atmospheric profiles and the GSW coefficients, we find that the LST retrieval error caused by ATI is larger than 0.3 K. To reduce the LST retrieval error associated with the ATI in the GSW algorithm, a quadratic equation as a function of ATI intensity is proposed. To validate the proposed method, some in situ measurements observed at the Hailar site are used. The results show that the proposed method could improve the LST retrieval accuracy by 0.47 K for atmospheres under ATI conditions.