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Schematic diagram of precipitation on the Tibetan Plateau (TP). Precipitation on the TP has a significant influence on climate, water resources, and terrestrial ecosystem. Here, we review recent progresses of precipitation on the TP based on observations (meteorological stations and satellite remote sensing) and simulations (global climate models and downscaling models), and discuss some mechanisms accounting for precipitation changes. Finally, we conclude a strategy for future research to further study the TP precipitation. Such review provides crucial implications for hydrological and precipitation studies over the TP.

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On the basis of meteorological station records during 1961–2010, we investigate the variations of temperature and precipitation in the Qaidam Basin. Results show that climate warming is significant in the region of Qaidam Basin over the past 50 years, with an average warming rate of 0.53 °C 10a−1. The largest and smallest warming rate happened at Mangya station (0.89 °C 10a−1) and Lenghu station (0.24 °C 10a−1), respectively. Seasonal warming was greatest in winter at eight meteorological stations, ranging from 0.43 °C 10a−1 (Lenghu station) to 1.01 °C 10a−1 (Delingha station). Since 1961, the annual precipitation has increased with a rate of 7.38 mm 10a−1. Seasonal precipitation mainly increased in summer (4.02 mm 10a−1). The maximum precipitation increase occurred at Delingha station (25.09 mm 10a−1) and the minimum at Lenghu station (0.10 mm 10a−1). The elevation dependency of warming trends is unremarkable because most of the stations are located at lower altitudes. It is suggested that sunshine duration is related to the tendencies of temperature increase at different stations. Pollution emissions from industrial processes (i.e. brown clouds) and urbanization are the main factors contributing to the warming climate. Furthermore, the predominant weakening of zonal wind speed over the Tibetan Plateau resulted from the global warming also contributes to the climate warming in the Qaidam Basin. Consequently, the warming rate in the Qaidam Basin is much higher than in other regions over the Tibetan Plateau. The Qaidam Basin is thus considered to be the most susceptible region with the most significant warming in the Tibetan Plateau.

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To optimize the description of land surface processes and improve climate simulations over the Tibetan Plateau (TP), a modified soil water‐heat parameterization scheme (SWHPS) is implemented into the Community Land Model 3.5 (CLM3.5), which is coupled to the regional climate model 4 (RegCM4). This scheme includes Johansen's soil thermal conductivity scheme together with Niu's groundwater module. Two groups of climate simulations are then performed using the original RegCM4 and revised RegCM4 to analyze the effects of the revised SWHPS on regional climate simulations. The effect of the revised RegCM4 on simulated air temperature is relatively small (with mean biases changing by less than 0.1°C over the TP). There are overall improvements in the simulation of winter and summer air temperature but increased errors in the eastern TP. It has a significant effect on simulated precipitation. There is also a clear improvement in simulated annual and winter precipitation, particularly over the northern TP, including the Qilian Mountains and the source region of the Yellow River. There are, however, increased errors in precipitation simulation in parts of the southern TP. The precipitation difference between the two models is caused mainly by their convective precipitation difference, particularly in summer. Overall, the implementation of the new SWHPS into the RegCM4 has a significant effect not only on land surface variables but also on the overlying atmosphere through various physical interactions.

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