Recently, Prof. ZHENG Donghai at the Institute of Tibetan Plateau Research, Chinese Academy of Sciences (CAS) (corresponding author), and Prof. SU Zhongbo (co-corresponding author) and Dr. ZHANG Pei (first author) at University of Twente, the Netherlands, published an article entitled "Status of the Tibetan Plateau observatory (Tibet-Obs) and a 10-year (2009-2019) surface soil moisture dataset" in Earth System Science Data (IF=11.333). This paper reports on the status of the Tibet-Obs and presents a 10-year (2009–2019) surface soil moisture (SM) dataset produced based on in situ measurements taken at a depth of 5 cm collected from the Tibet-Obs that consists of three regional-scale SM monitoring networks, i.e. the Maqu, Naqu, and Ngari (including Ali and Shiquanhe) networks. The dataset is now published in the National Tibetan Plateau/Third Pole Environment Data Center (https://data.tpdc.ac.cn/en/) and is openly available to users.

Surface soil moisture is an important variable controlling land-air processes, and its observation data play an important role in developing, validating and improving satellite inversion algorithms and model simulations. The Tibet-Obs was established in 2008, consisting of four station networks in Magu, Naqu, and Ngari (including Ali and Shiquanhe (Figure 1), and the Decagon 5TM ECH₂O probes are used to measure the soil moisture and soil temperature at nominal depths of 5, 10, 20, 40, and 60/80 cm at each station at a frequency of 15 min. The Tibet-Obs was established by Prof. Bob Su's group at the University of Twente, the Netherlands, Prof. WEN Jun's group at Chengdu University of Information Engineering, and MA Yaoming's group at the Institute of Tibetan Plateau Research, Chinese Academy of Sciences. It has been in continuous operation for more than ten years by Dr. WANG Xin of Northwest Institute of Eco-Environment and Resources, CAS, Prof. ZHENG Donghai of Institute of Tibetan Plateau research, CAS, and Dr. ZENG Yijian of ITC, and has been selected by NASA's Soil Moisture Active and Passive Satellite (SMAP) as the ground verification site for its products.

Figure 1. Coordinates of Tibet-Obs and distribution of each station.

Trend analysis of the 10-year upscaled SM records indicates that the Shiquanhe network in the western part of the TP is getting wet, while there is no significant trend found for the Maqu network in the east. The continuous long time series soil moisture data is the key information for environmental and climate change monitoring on the Tibetan Plateau, and this dataset is the longest time series soil moisture observation data on the Tibetan Plateau, which is an important reference value for land surface environmental and climate change research.

This study was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (grant no. XDA20100103) and the National Natural Science Foundation of China (grant nos. 41971308 and 41871273).

Article:

Zhang, P., Zheng, D., van der Velde, R., Wen, J., Zeng, Y., Wang, X., Wang, Z., Chen, J., and Su, Z.: Status of the Tibetan Plateau observatory (Tibet-Obs) and a 10-year (2009–2019) surface soil moisture dataset, Earth Syst. Sci. Data, 13, 3075–3102, https://doi.org/10.5194/essd-13-3075-2021, 2021.

Data available at:

http://www.tpdc.ac.cn/en/data/d323f0b2-dada-4ed5-aa00-57564da788d2/