树轮记录的过去517a博州中东部年平均最低气温变化

Mean minimum temperature change recorded in the tree-ring in the middle and east of Boertala Mongolia Autonomous Prefecture

利用采自博州中东部山区上树线JPK采样点的雪岭云杉树轮样本,分析了其年表特征及对气候响应。结果表明:采样点树轮宽度标准化年表与博乐和精河气象站上年12月至当年11月平均最低气温具有很好的正相关关系。用JPK采点树轮宽度标准化年表序列,重建了博州中东部地区年平均最低气温,相关系数0.586,方差解释量达34.3%(调整自由度后为33.0%)。过去517年来,博州中东部地区平均最低气温变化存在7个偏冷阶段和7个偏暖阶段。重建序列具有3a、3.8a和5a左右的准周期,并且在1568年前后、1667年前后、1708年前后、1734年前后和1845年前后发生了突变。

Using tree ring of Picea schrenkiana sampled from the upper treeline in the Middle and East of Boertala Mongolia Autonomous Prefecture, JPK tree - ring width standardized chronology was established to analyze the characteristics of the chronology and their responds to climate factors. The JPK chronology was found having correlation with the annual mean minimum temperature of Bole and Jinghe stations. Annual mean minimum temperatures of middle and east of Boertala Mongolia Autonomous Prefecture were reconstructed by the tree - ring width standardized chronology, which explained 34.3 % of the variance in the reconstruction （ F = 25. 611, P 〈 0. 0001 ）. After analyzing, it was found that there were 7 warm and 7 cold periods in the area in recent 517 years. The temperature reconstruction has a good response to the temperature reconstructions from tree - ring and glacial change. The results revealed the common climatic extremes and climate change over north - west China. The power spectrum analysis shows that there were 3a, 3.8a and 5a cycles in our reconstruction, which may be associated with ENSO. The moving t - test indicates that the significant abrupt changes were presented in about 1568A. D. , 1667 A. D. , 1708 A. D. , 1734 A. D. and 1845 A. D.