Tree-Ring Stable Carbon Isotope-Based Mean Maximum Temperature Reconstruction in Northwest China and Its Connection with Atmospheric Circulations

The inter-annual stable carbon isotope ratio (δ13C) of three tree-ring cores P. euphratica (Populus Oliv.) was determined from Ejina Oasis in Northwest China. A robust and representative δ13C chronology is generated the series using an arithmetic mean method. After eliminating influence elevated atmospheric dioxide (CO2) concentration, we obtained a isotopic discrimination (Δ13C) chronology. According to significant correlation between Δ13C instrumental data, reconstructed maximum temperature anomalies previous December current September (TDS) for period 1901–2011. reconstruction explained 43.6% variance over calibration period. Three high-temperature periods (1929–1965, 1972–1974, 1992–2006) low-temperature (1906–1926, 1966–1968, 1975–1991) were found series. Comparisons TDS observed Anxi meteorological station index north-central China demonstrated has advantage reliability stability. spatial declared that broad representation can represent variation characteristics wide geographical area. In addition, area smaller (larger) when higher (lower), which may be due conjunction effect natural anthropogenic activities. Significant periodicities correlations suggested variations regulated by solar radiation circulations at interannual interdecadal time scales.