The effects of changes in HITRAN and the water vapor continuum model on infrared radiative transfer calculations and remote sensing applications

Abstract

This study examines the implications of recent updates to the High Resolution Transmission (HITRAN) database and the MT_CKD water vapor continuum model on infrared radiative transfer calculations and satellite remote sensing applications. Specifically, it assesses the impact of the latest versions of the HITRAN database (i.e. HITRAN2016 and HITRAN2020) and the MT_CKD WV continuum model (i.e. versions 3.2 and 4.1.1) on clear-sky infrared flux calculations and the simulation of satellite infrared channels, specifically those of the Geostationary Operational Environmental Satellite (GOES) Advanced Baseline Imager (ABI). The results indicate that updates to the MT_CKD model tend to reduce atmospheric opacity, while updates to the HITRAN database have the opposite effect. The most significant differences noted are attributed to updates in the MT_CKD, leading to an increase in upward flux of 0.13 Wm−2 for the TRO and a decrease in downward flux of 0.28 Wm−2 for the MLS profile. However, these impacts are not uniform across the spectrum, atmospheric height, or among different atmospheric profiles. Notably, changes in the WV continuum model have significant effects in the far-infrared region. The updates in HITRAN exhibit pronounced differences associated with changes in the spectroscopic parameters of H2O, CO2 and O3. The results of GOES’ ABI channels indicate that changes in HITRAN lead to an average brightness temperature decrease of 0.3 K for channel 12, which exceeds the channel’s sensitivity. This research underscores the importance of continuous updates and evaluations of spectroscopic databases and radiative transfer models to improve the accuracy of atmospheric remote sensing data.