Tree-Ring Reconstruction Of June-July Mean Temperatures In The Northern Daxing'An Mountains, China

In this study, the mean temperature of June to July was reconstructed for the period of 1880 to 2014 by using the Larix gmelinii tree-ring width data for the Mangui region in the northern Daxing'an Mountains, China. The reconstruction accounts for 43.6% of the variance in the temperature observed from AD 1959-2014. During the last 134 years, there were 17 warm years and 17 cold years, which accounted for 12.7% of the total reconstruction years, respectively. Cold episodes occurred throughout 1887-1898 (average value is 14.2 degrees C), while warm episodes occurred during 1994-2014 (15.9 degrees C). Based on this regional study, the warmer events coincided with dry periods and the colder events were consistent with wet conditions. The spatial correlation analyses between the reconstructed series and gridded temperature data revealed that the regional climatic variations were well captured by this study and the reconstruction represented a regional temperature signal for the northern Daxing'an Mountains. In addition, Multi-taper method spectral analysis revealed the existence of significant periodicities in our reconstruction Significant spectral peaks were found at 29.7, 10.9, 2.5, and 2.2 years. The significant spatial correlations between our temperature reconstruction and the El Nifio-Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and Solar activity suggested that the temperature in the Daxing'an Mountains area indicated both local-regional climate signals and global-scale climate changes.