The Qinghai-Tibet Plateau (QTP) is underlain by typical high-altitude permafrost region, which is undergoing more dramatic climatic warming than its surrounding regions. Under the scenarios of climate warming, the mean annual ground temperature (MAGT) of permafrost on the QTP has risen to some extent, the active layer has thickened, and the thickness and extent of permafrost has reduced. The changes of MAGT and ALT could affect the ecosystem of the QTP by altering the ground ice evolution, hydrological processes, vegetation dynamics and carbon cycling, etc. Therefore, it is of great importance to investigate present and future changes of the MAGT and ALT in the permafrost region. 

In recent years, with the development of new technology and disciplines, statistical and machine learning models have been increasingly applied to geoscience research, and great progress have been made. Professor Wu Tonghua with his team from the State Key Laboratory of Cryospheric Science used a combination of statistical and machine learning methods to simulate and predict the current and future changes of MAGT and ALT in the permafrost region of the QTP. The advantage of this method is that the model requires little input data and can quickly obtain the thermal status and ALT information in the permafrost region of the QTP. The results show that the application of the statistical and ML method is reliable on the QTP permafrost regions, with the root-mean-square error of 0.53°C and 0.69 m for the MAGT and ALT, respectively. The present (2000-2015) permafrost area on the QTP is 1.04 × 10⁶ km² (0.80-1.28 × 10⁶ km²), and the average MAGT and ALT are -1.35 ± 0.42°C and 2.3 ± 0.60 m, respectively (Figure 1 and Figure 2). 

In the future (2061-2080), the area of permafrost (within 10m of the surface) on the QTP will decrease significantly, especially for the RCP8.5, the permafrost area will be reduced to 42% of the existing area. Uunder the RCP2.6, the MAGT over the QTP permafrost regions will increase from -1.35°C (present status) to -0.66°C by 2061-2080 (RCP2.6) and to 0.25°C for RCP8.5. The ALT was predicted to increase from 2.3 m (2000-2015) to 2.7 m (2061-2080) for RCP8.5..In general, the future changes of MAGT and ALT on permafrost region of the QTP were pronounced, but region-specific 

This work was supported by the National Natural Science Foundation of China (41690142, 41771076, 41961144021, 42071093), the CAS “Light of West China” Program. 

Contact:

WU Tonghua

E-mail: thuawu@lzb.ac.cn

Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China.