Annualmeeting:2017 CSDMS meeting-055


Browse  abstracts

Modeling permafrost thermal state and active layer thickness on the Qinghai-Tibet Plateau, China

yanhui qin, Chinese Academy of Sciences Lanzhou , China.
tonghua wu, Chinese Academy of Sciences Lanzhou , China.

[[Image:|300px|right|link=File:]]In China, permafrost is mainly underlain on the Qinghai-Tibet Plateau (QTP), which is the largest mid-low latitude permafrost region in the world. Owing to the unique and extremely high altitude, permafrost area on the QTP approximately amounts to 1.06 million km2. Permafrost on the QTP is one of the most sensitive indicators to global climate change, because it is the product between the earth and atmosphere system. The active layer is the interface between the earth and atmosphere. To understand the present condition of active layer and permafrost thermal state is the foundation to learn about the hydrological cycles, infrastructures built on and in permafrost, soil carbon release and uptake, and biogeochemical and ecological processes in cold regions. The observations can depict the present state of permafrost, but models are eventually essential to predict future changes of permafrost. Despite the fact that geophysical surveys and boreholes are the most reliable sources of information about permafrost, they are extremely costly and are mostly available from relatively small regions. I tried to implement the Geophysical Institute Permafrost Lab Version2 (GIPL2) model on the Qinghai-Tibet Plateau (QTP). The GIPL2 model can provide more permafrost thermal state than those of statistical empirical models. I am interested in applying the GIPL2 model to the Qinghai Tibet Plateau in order to know the thermal state of QTP permafrost and its response to recent climate changes. The results of our present work using the original version of GIPL2 indicated that for the whole permafrost area of the QTP, the simulated ALT ranges from 0 to 8 m, with an average of 2.30 m. The simulated 18 ALT sites are generally underestimated compared with the observed values with the MBE value of -0.14 m and the RMSE value of 0.22 m.