A 216-year tree-ring reconstruction of April–July relative humidity from Mt. Shiren, central China

Abstract

Long-term relative humidity change in central China has been rarely studied due to the shortness of instrumental records. In this study, we developed an annually resolved tree-ring width chronology dating back to 1727 coefficient of efficiency (CE) with Chinese pine (Pinus tabulaeformis Carr.) samples from Mt. Shiren, central China. Relative humidity of current April–July (RHAJ) was reconstructed for the region from 1801 to 2016 CE using a linear regression model, which explains 43.9% of the variance in the instrumental records from 1960 to 2016 CE. The reconstructed RHAJ revealed that there were 33 extremely dry years, accounting for 15.28% of the past 216 years. The five driest years and the corresponding anomalies were 1835 (60.05%), 1955 (60.24%), 1929 (60.50%), 1907 (60.71%), and 1801 (60.83%). In agreement with the PDSI reconstruction for Mt. Shennong and the drought/flood series in Zhengzhou, the reconstructed RHAJ captured common droughts in 1813–1814, 1847, 1876–1880, 1900, 1923–1945, 1960–1961, and wet periods in 1863–1872, 1882–1885, 1897–1898, 1954–1956, and 1983–1984. Spatial correlation analyses showed that the reconstructed RHAJ for Mt. Shiren had significant positive correlations with vapour pressure, precipitation, and relative humidity of 850 hPa around the study area, which indicates that the reconstructed RHAJ reflects regional humidity change in central China. To sum up, these results may be provide us with a better understanding of drought variation in central China.