Abstract
In the context of global warming, the frequency and intensity of extreme weather and climate events have increased, especially in Central Asia (CA). In this study, we investigate the characteristics of Summer Extreme Precipitation (SEP) in CA and its relationship with the Surface Sensible Heat (SSH) variation over the Central-Eastern Tibetan Plateau (CETP). Our results suggest that the distribution of SEP in CA is extremely uneven, and the SEP threshold ranges from 2 to 32 mm, 80% of them are concentrated in the range of 4–10mm. Both the total amount of SEP and the number of SEP days show significant increasing trends, with the climatic tendencies of 4.4 mm/decade and 0.4 day/decade, respectively. The SSH anomalies over the CETP can affect the SEP and the summer drought in CA by regulating the strength of the SAH and the subtropical jet over CA. The strong SSH anomalies over the CETP in late spring (April-May) can lead to the anomalously strong SAH in summer, anomalously weak subtropical westerly jet over CA and anomalously strong subtropical high over north Africa and the Arabian Peninsula. In addition, the Ural ridge strengthens, the CA trough weakens, and the northern CA is controlled by an abnormal warm high-pressure ridge with less anomalous water vapor convergence. Therefore, the SEP in northern CA will be abnormally less and the summer drought intensifies. Whereas, when the SSH over the CETP is anomalously weak in late spring, the key circulation characteristics are quite the opposite, at the same time, the anomalous water vapor from the Arctic, North Atlantic and western Pacific converges in northern CA and northern Xinjiang, China, which are conducive to the generation of widespread extreme precipitation and alleviates the summer drought in these regions.
Multi-terrane structure controls the contrasting lithospheric evolution beneath the western and central–eastern Tibetan plateau
