A method to separate temperature and precipitation signals encoded in tree-ring widths for the western Tien Shan Mountains, northwest China

摘要: Abstract Separating temperature and precipitation signals encoded in tree rings is a complicated issue. Here, we present separation method by combining two tree-ring width chronologies of Schrenk's spruce ( Picea schrenkiana ) from the upper lower timberlines western Tien Shan Mountains, northwest China. Correlation analyses show that both correlate positively with precipitation. However, correlates chronology timberline, while negatively timberline. This suggests contain similar information but opposite signals. In light this, calculated average difference chronologies, found each them has much stronger correlation or alone. Finally, reconstructed local variations over past 201 years using chronologies. The reconstructions do not have significant correlation, they positive negative relationships on high- low-frequency band, respectively.