The decadal variability and its cause of the extreme drought in china

Abstract

This paper investigates the probability of extreme drought in four regions of China during the 1470—2000 A.D., and analyzes the δ18O record in Guliya ice core. By wavelet analysis, we find that the probability of drought in the four regions has the quasi-cycle of 350a, like the δ18O record in Guliya ice core. When the δ18O record is high, the temperature of Qinghai-Xizang Plateau is high too, and the probability of drought is low, and vice versa. This paper also analyzes the Pacific decadal oscillation and finds the quasi-cycle of 80a is weakening but the quasi-cycle of 50a is enhancing. When either of them is strong, the probability of drought is high, and the probability is low when the two quasi-cycles are alternating.