The Tibetan Plateau (TP), the highest and largest plateau in the world, with complex and competing cryospheric‐hydrologic‐geodynamic processes, is particularly sensitive to anthropogenic warming. The quantitative water mass budget in the TP is poorly known. Here we examine annual changes in lake area, level, and volume during 1970s–2015. We find that a complex pattern of lake volume changes during 1970s–2015: a slight decrease of −2.78 Gt yr⁻¹ during 1970s–1995, followed by a rapid increase of 12.53 Gt yr⁻¹ during 1996–2010, and then a recent deceleration (1.46 Gt yr⁻¹) during 2011–2015. We then estimated the recent water mass budget for the Inner TP, 2003–2009, including changes in terrestrial water storage, lake volume, glacier mass, snow water equivalent (SWE), soil moisture, and permafrost. The dominant components of water mass budget, namely, changes in lake volume (7.72 ± 0.63 Gt yr⁻¹) and groundwater storage (5.01 ± 1.59 Gt yr⁻¹), increased at similar rates. We find that increased net precipitation contributes the majority of water supply (74%) for the lake volume increase, followed by glacier mass loss (13%), and ground ice melt due to permafrost degradation (12%). Other term such as SWE (1%) makes a relatively small contribution. These results suggest that the hydrologic cycle in the TP has intensified remarkably during recent decades.

Research has revealed systematic changes in warming rates with elevation (EDW) in mountain regions. However, weather stations on the Tibetan plateau are mostly located at lower elevations (3,000‐4,000 m) and are nonexistent above 5,000 m, leaving critical temperature changes unknown. Satellite LST (Land Surface Temperature) can fill this gap but needs calibrating against in situ air temperatures (T_air). We develop a novel statistical model to convert LST to T_air, developed at 87 high‐elevation Chinese Meteorological Administration stations. T_air (daily maximum/minimum temperatures) is compared with Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua LST (1330 and 0130 local time) for 8‐day composites during 2002‐2017. Typically, 80‐95% of the difference between LST and T_air (ΔT) is explained using predictors including LST diurnal range, morning heating/nighttime cooling rates, the number of cloud free days/nights, and season (solar angle). LST is corrected to more closely represent T_air by subtracting modeled ΔT. We validate the model using an AWS on Zhadang Glacier (5800 m). Trend analysis at the 87 stations (2002‐2017) shows corrected LST trends to be similar to original T_air trends. To examine regional contrasts in EDW patterns, elevation profiles of corrected LST trends are derived for three ranges (Qilian Mountains, NyenchenTanglha, and Himalaya). There is limited EDW in the Qilian mountains. Maximum warming is observed around 4,500‐5,500 m in NyenchenTanglha, consistent with snowline retreat. In common with other studies, there is stabilization of warming at very high elevations in the Himalaya, including absolute cooling above 6,000 m, but data there are compromised by frequent cloud.

Improved daily precipitation and temperature data at 5 × 5‐km grids for 1960–2015 were developed for the Upper Yarkant basin (UYB) based on observations of precipitation gradients and temperature lapse rates. The developed climate data are then used to drive the VIC‐Glacier hydrological model to simulate the runoff process for the UYB. A large altitudinal dependence is observed in both precipitation and temperature, with three altitudinal patterns of precipitation gradient for the elevation bands of 3,000 m, respectively, and a strong seasonal variation in temperature lapse rate ranging from 0.4 to 0.8 °C/100 m. Basin precipitation and temperature data are greatly improved in both amount and spatial variations after the orographic adjustments. Glacier melt runoff is the dominant water source of the UYB accounting for about 52% of annual total flows, followed by snowmelt (about 26%), and rainfall runoff (about 22%). About 60% of basin runoff originates from the high altitudes (>5,000 m), and about 32% and 8% of runoff originate from middle (4,000–5,000 m) and low (<4,000 m) altitudes, respectively. The variations in annual runoff in the UYB were mainly controlled by glacier melt runoff, middle and high altitudes, and temperature in warm seasons during 1965–2015. However, rainfall and snowmelt runoff, and low altitudes, were playing an increasingly important role in total flow variations of the UYB due to the increase of warm season temperatures in 1994–2015 and precipitation in the entire simulation period.