Atmospheric water cycle (AWC) plays a critical role in precipitation in semi-arid areas; empirical studies indicated that climate change accelerates water cycles, which is an important factor resulting in wet places getting wetter while dry places becoming drier. However, the mechanism on that is far from being well understood, that is, how does the AWC affect regional climate in multiple scales? We analyzed the precipitation in mountains and plains respectively and unveiled their relationships with multi-scale AWC over Tarim River Basin , the largest inland valley globally, in which warming-wetting appeared in its western part.
Results/Conclusions
We found a consistent growth decadal trend and high correlation between precipitation in mountains and small-scale AWC, whereas plains precipitation and large-scale AWC are highly correlated and changing concordantly with a slow downward trend. We demonstrated that the accelerated small-scale AWC leads to the increase in mountains precipitation and the emergence of warming-wetting under global warming, due to the glacier melting and forest pump. Our results suggested that, if large-scale AWC is getting weaker, semi-arid areas may be faced with a transition from warming-wetting to getting drier, and finally degenerate to arid regions, as a result of the reduction of local water resources with future global warming.