Tree‐ring oxygen isotope recorded precipitation variations over the past two centuries in the northeast Chinese Loess Plateau

Abstract

AbstractIt was shown in previous studies that tree‐ring oxygen isotope (δ18OTR) was a proxy of regional precipitation. Using two δ18OTR chronologies of Pinus tabulaeformis Carr. in northeast Chinese Loess Plateau (CLP), we synthesized a master series which had a high correlation with regional precipitation from previous‐year September to current‐year August (PSA) (r = −0.650, N = 52, p < .001). Thus we reconstructed the PSA over the past two centuries (AD 1808–2009) for the northeast CLP. The results of calibration–verification tests indicated that the precipitation reconstruction was stable and reliable. Compared with reconstructions based on the tree‐ring width and historical documents, the PSA reconstruction reserved more decadal low‐frequency climate signals such as the drying trend since the 1930s. Superposed epoch analysis (SEA) showed that the large tropical volcanic eruptions significantly reduced PSA in the first year after the eruptions. The contrast of the regional precipitation reconstructions in the west, northeast, and southeast CLP demonstrated that spatial and temporal differences of precipitation variation. In terms of extreme climate events, major droughts in the mid‐to‐late 1920s were recorded in all three regional precipitation records, while the Ding‐Wu Disaster (AD 1876–1878) was only found in the southeast CLP. Under the background of the weakening Asian monsoon and global warming, CLP was more prone to droughts in the last five decades.