Abstract:

Land surface temperature (LST) is a crucial parameter of surface energy budget and controls the thermal regime of the active layer in permafrost regions. However, there are limited observed datasets available for the Tibetan Plateau, with greater bias in the LST products from remote sensing data. In this study, the LST calculated with the upward and downward long-wave radiation data from the three automatic weather stations were compared with the MODIS LST products. Meanwhile, the LST retrieved from Landsat 5 TM and Landsat 7 ETM+ was also compared with MODIS LST to explain the consistency between remote sensing data with different resolutions. In daytime, the mean absolute error (MAE) and the root-mean-square error (RMSE) of MODIS LST products were about 3.42~4.41 ℃ and 4.41~5.29 ℃, respectively. In nighttime, the MAE and the RMSE of MODIS LST products were about 2.15~2.9 ℃ and 3.05~3.78 ℃, respectively, indicating that the nighttime MODIS LST have a better accuracy. Both of the LSTs retrieved from TM and ETM+ have a good consistency with MODIS LST, with the correlation coefficients of greater than 0.85 and 0.95 for TM and ETM+, respectively. MODIS LST products have a high applicability in continuous permafrost regions in the Tibetan Plateau, which is a potential dataset for monitoring permafrost thermal regime. The consistency between Landsat TM/ETM+ LST and MODIS LST is also high. The results can be used to monitor and model permafrost with remote sensing data of multi-sources

Key words: Tibetan Plateau, land surface temperature (LST), MODIS, upward and downward long-wave radiation, Landsat TM/ETM+