Evidence for elevation-dependent warming from the Chinese Tianshan Mountains

The phenomenon that the warming rate of air temperature is amplified with elevation is termed elevation-dependent warming (EDW). It has been clarified that EDW can accelerate the retreat of glaciers and the melting of snow, which would have significant impacts on regional ecological environment. Owing to the lack of high-density ground observations in the high mountains, there is a widespread controversy on the existence of the EDW. Current evidences are mainly derived from some typical high mountains such as the Swiss Alps, the Colorado Rocky Mountains, the Tropical Andes and the Tibetan Plateau/Himalayas. Rare evidences in other mountains have been reported, especially in arid regions. In this study, EDW features in the Chinese Tianshan Mountains (CTM) are detected using a unique high-resolution (1 km, 6-hourly) air temperature data set (CTMD). The results showed that there are significant EDW signals at different altitudes on different time scales. The warming rate of the minimum temperature in winter shows significant elevation dependence, especially above 4000 m. The greatest altitudinal gradient in the warming rate of maximum temperature is found above 2500 m in April. For the mean temperature, the warming rates in January, February and March show prominent EDW features but with different significances. Within the CTM, the Tolm Mountains, the eastern part of the Borokoonu Mountains, the Bogda Mountains and the Balikun Mountains are the representative regions that show significant EDW features on different time scales. This new evidence partly explains the accelerated melting of glaciers in spring in the CTM.

A high-resolution air temperature data set for the Chinese Tianshan Mountains in 1979–2016

The Chinese Tianshan Mountains has a complex ecological environment system. It not only has a large number of desert oases, but also gave birth to a large number of glaciers. The arid climate and the shortage of water resources are the important factors to restrict the socio-economic development in this area. This study presents a unique high-resolution (1 km, 6-hourly) air temperature data set for the Chinese Tianshan Mountains (41.1814–45.9945° N, 77.3484–96.9989° E) from 1979 to 2016 based on a robust statistical downscaling framework. The data set was validated by 24 meteorological stations at daily scale. Compared with original ERA-Interim temperature, the Nash-Sutcliffe efficiency coefficient increased from 0.90 to 0.94 over all test sites. Around 24 % of root-mean-square error was reduced from 3.75 to 2.85 °C. A skill score based on the probability density function, which was used to validate the reliability of the new data set for capturing the distributions, enhanced from 0.86 to 0.91 for all test sites. We conclude that the new high-resolution data set is reliable for climate change investigation over the Chinese Tianshan Mountains. This data set would be helpful for the potential users for better local climate monitoring, modelling and environmental studies in the Chinese Tianshan Mountains. The data set presented in this article is published in Network Common Data Form (NetCDF) at doi:10.1594/PANGAEA.887700. The data set includes 288 nc files and one user guidance in txt file.

Presence of the snow leopard Panthera uncia confirmed at four sites in the Chinese Tianshan Mountains

The Endangered snow leopard Panthera uncia is a flagship species of mountainous central Asia, and a conservation concern. China has the largest extent of potential snow leopard habitat and is thus crucial for snow leopard conservation. There are many challenges to snow leopard conservation in China, however, and there is still little information on the species for many geographical locations, including the Tianshan Mountains of Xinjiang province, which are important because they potentially connect snow leopard populations in Krygyzstan and Kazakhstan with those in Mongolia. We used camera traps in four areas across eastern, central and western Tianshan, with a total survey effort of 3,216 camera-trapping days. We confirmed the presence of snow leopards and an abundance of potential snow leopard prey, including the Siberian ibex Capra sibirica, in all areas. We found 2–3 individual adult snow leopards at each site, with relatively limited survey effort, and more study is needed to fully investigate the importance of the Tianshan Mountains for the species. Establishing more protected areas is essential for snow leopard conservation, and we have used data from this study to apply for protected area status for several areas.