Cloud properties and dynamics over the Tibetan Plateau – A review

Abstract

Cloud properties over the Tibetan Plateau (TP) and their underlying dynamics play a crucial role in the energy balance and regional water cycle of the climate system. In this review, we assess the progress in observational methods and model simulations of cloud macro- and micro-physical properties over the TP since the 1960s. We summarize the spatiotemporal patterns of cloud distribution and the main drivers, discussing the difficulties posed by cloud dynamics and their feedback into climate change on the TP. In short, we found that while the TP is warming and wetting, total cloud cover has decreased over the TP from 1960 to 2021 and from the southeast to the northwest, which typically exhibits the largest proportion of high cloud cover (HCC) and mid-high cloud cover. Meteorological elements (such as air temperature, precipitation), topography, and atmospheric circulation are the main factors influencing cloud formation. During the warm season (May–October), the intensification and northward shift of the South–Asian High and the South Asian monsoon lead to an uneven distribution of precipitation over the TP, while the Indian monsoon promotes the formation of low cloud cover. During the cold season (November–April), the northward expansion of the Hadley circulation inhibits the formation of HCC and middle cloud cover. The amount of cloud cover also affects climatic warming on the TP by radiative forcing. We end the review with a discussion of future research challenges, and propose to focus on improving the accuracy of model parameterizations to facilitate a deeper understanding of the effects of climate change on the TP and the associated water cycle processes.