Can the ERA5 Reanalysis Product Improve the Atmospheric Correction Accuracy of Landsat Series Thermal Infrared Data?

Atmospheric correction is a key step toward estimating land surface temperature from the sensor with only one thermal infrared (TIR) channel. We use ground radiosounding profiles collected from 163 radiosonde observations to provide insights on how well the ERA5 reanalysis product performs in the atmospheric correction of Landsat series TIR data. Despite the poor performance of the ERA5 product for estimating atmospheric upward radiance, downward radiance, and transmittance of Landsat series TIR data in the Americas and Africa, the performance of the ERA5 product was superior to that of the M2I6NPANA (inst6_3d_ana_Np) dataset (MERRA2) and (Final) Operational Global Analysis data (FNL) products in Asia and Europe. The vertical distribution of air temperature and relative humidity profiles may explain the poor performance of ERA5 in the Americas and Africa. This letter shows the advantages and weaknesses of the ERA5 reanalysis product in the atmospheric correction of Landsat series TIR data and will benefit research fields that require an atmospheric profile as input.