Tree-ring width-based precipitation reconstruction in Zhaogaoguan, China since 1805 AD

In order to further understand the past climate variation especially the history of drought and flood events in the East Asian summer monsoon (EASM) marginal area, precipitation from previous August to current July for the period of 1805–2014 AD was reconstructed from a ring-width chronology of Pinus tabulaeformis in Zhaogaoguan (ZGG), a site located in the EASM marginal area in northern China. The transfer function can explain 46.4% (adjusted to 45.4% for the loss of degrees of freedom) of the variance of the observed precipitation during the calibration period (1958–2014 AD). The reconstructed precipitation series revealed that the inter-annual variability was very prominent; 1843 and 1844 AD were the two wettest years, while 1931 and 1999 AD were the two driest years. We noticed that the droughts in 1900, 1906, 1931, 1955 and 1999 AD in the reconstruction series corresponded to the severe floods in the Yangtze River watershed in southern China during those same years. This phenomenon confirmed the typical climate pattern of northern droughts and southern floods in China. Moreover, the reconstructed precipitation series in ZGG showed synchronous variation patterns with the other tree-ring-based hydrological reconstructions in the marginal area of EASM on both inter-annual and inter-decadal scales, indicating the common precipitation variation characteristics of the EASM marginal area.