川西高原树木年轮所指示的平均最高气温变化

本文利用川西高原4条树木年轮年表序列,分析了树轮年表和川西高原气象要素的关系。通过响应函数计算得出,树轮年表对川西高原6月的平均最高气温反映敏感,由此重建了该地1617~1994年6月的平均最高气温序列,并应用交叉检验方法对校准方程进行了检验,证明重建方程稳定,具有区域代表性。在重建的378 a中,10 a尺度的显著较高时段有2个,即1651~1670、1941~1960年;显著的较低时段有7个,即1691~1730、1741~1760、1771~1790、1801~1820、1831~1900、1911~1940年和1961~1990年。平均约27 a发生一次10 a尺度的突变,19、20世纪是川西高原6月平均最高气温的多变时期,17、18世纪是平均最高气温的相对稳定时段。19世纪20年代和20世纪40年代升温显著,20世纪70~80年代降温比较显著。

Average Maximum Temperature Change Recorded by Tree Rings in West Sichuan Plateau

The article analyzed the relationship between tree ring-width chronologies and the meteorological elements in west Sichuan plateau by sequential analysis of 4 tree-ring chronologies.The response function analysis showed that the chronologies were sensitive to average maximum temperature in July in plateau.It helped to reconstruct the average maximum temperature from 1617 to July of 1994 in plateau.Based on the cross-validation method,it checked the stability of the calibration equation,the result indicated that the equation was stable and meaningful.In 378 years' rebuilding data,there're two decadal high significance period of time,which are 1651-1670 and 1941-1960.There're seven decadal low significance period of time,which were 1691-1730,1741-1760,1771-1790,1801-1820,1831-1900,1911-1940 and 1961-1990.Decadal mutation took place every twenty-seven years,the variable period of average maximum temperature occurred in 19th and 20th century,the relative stable period occurred in 17th and 18th century.It showd that the significance temperature rising occurred in the 1820s and 1940s,temperature dropping occurred from 1970s to 1980s.