Climate change in the Hongliujing area of Lop Nur over the past 200 years revealed by the stable oxygen isotopes of Tamarix cones

The layers of Tamarix cones within sedimentary deposits in arid regions have significant chronological and paleoenvironmental implications. Here, we compare the δ 18 O values of Tamarix cones in the Hongliujing area of Lop Nur with meteorological data for the Ruoqiang meteorological station for 1960–2019 AD. Linear regression analysis was used to reconstruct the average temperature for April and the precipitation for November in the Hongliujing area over the past 200 years. The results showed that the δ 18 O values were significantly negatively correlated with the temperature for February, April, May, August, December, and with the annual mean temperature; significantly negatively correlated with the precipitation for February and April; significantly negatively correlated with the sunshine hours for March and May; significantly positively correlated with the sunshine hours for February, July, August, October, and December, and with the annual mean values; and significantly correlated with the relative humidity for April, July, August, September, October, and November, and with the annual mean values. Based on the δ 18 O record of the past 200 years, the Hongliujing area experienced two warm-wet periods (1874–1932 and 2004–2019 AD) and two cold-dry periods (1832–1873 and 1933–2003 AD). Thus, the climate was characterized by alternating warm-wet and cold-dry conditions. Wavelet analysis revealed three main cycles: 45 years, 29 years, and 14 years.