基于树轮的阿勒泰地区1818-2006年1-2月降雪量重建与分析

Reconstruction and Analysis of January-February Snowfall in the Altay Prefecture during 1818-2006

依据采自新疆阿勒泰中东部地区的树木年轮样本,建立了该地区8个采点的树轮宽度年表.相关普查发现,标准化树轮宽度年表序列与该地区1-2月的降雪量存在明显的正相关关系,且具有显著的树木生理学意义.用义河山南(t)、卓勒萨依(t+2)和哈拉额尔齐斯(t+3)三个标准化树轮宽度年表序列可以较好地重建该地区1818-2006年189a来当年1-2月的降雪量,且经过交叉检验表明重建方程稳定可靠.分析发现,阿勒泰地区189a来降雪量的重建序列具有5个偏少阶段和5个偏多阶段,并具有2.4a,3.3～3.4a和63a的显著干湿变化准周期.冬季降雪量的重建序列大致存在4个突变点,其中在1847年和1930年前后为降雪量由多到少突变,而在1901年和1986年前后是自少向多突变.

Eight tree-ring chronologies in middle and eastern Altay Prefecture were established.The correlation between the climatic data and the chronologies was analyzed.It is found that the standardized chronology series positively correlates with the snowfall from January to February in the prefecture,and has obvious tree physiological significance.With the three chronologies YHN（t）,ZLS（t＋2） and HLE（t＋3）,the 189 a（1818-2006） snowfall from January to February can be better reconstructed,and the reconstructed equation is reliable.It is found that： 1） The reconstructed snowfall has five wetter periods above their mean and five drier periods below their mean.2） The reconstructed series has significant cycles of 2.4 a,3.3~3.4 a and 63 a periods.3） The abruptly change of the reconstructed snowfall series occurred in 1847,1901,1930 and 1986,of which the change was from more to less in 1847 and 1930,while the change was from less to more in 1901 and 1986.