利用树轮重建秦岭地区历史时期 初春温度变化

采用树木年轮气候学方法，利用秦岭地区树轮长年表资料重建秦岭地区历史时期初春温度，表明各气象站点重建序列与器测序列均呈显著的正相关关系，其中重建序列与实测记录的相关系数最高可达0．7以上，其他站的相关系数取值也均接近或超过0．6，说明重建序列能较好地反映秦岭地区的初春温度变化。对重建序列的分析结果表明，近300年来秦岭地区的初春温度变化存在明显的冷暖时段：1715～1740年、1773～1804年和1893～1958年三个时段的初春温度相对较高，持续时间分别为26年、32年和66年；而174l～1772年、1805～1892年、1959～1992年三个时段的初春温度相对较低，持续时间分别为32年、88年和34年，在整体上具有升温快速降温缓慢的特征。重建结果的变化趋势与其他相关研究结果极为一致。但是在20世纪后期，无论是在重建序列还是在器测序列中至少到1992年均未反映出明显的增温趋势。秦岭西部地区初春季节变冷与增暖的幅度均大于秦岭中东部地区。此外，秦岭地区初春温度变化具有100年左右、50～60年、7～8年以及2～3年等准周期变化特征。

Reconstruction of Early-Spring Temperature of Qinling Mountains Using Tree-Ring Chronologies

In this paper, tree ring chronologies were used to reconstruct early-spring temperature in the Qinling Mountains of China. The reconstructed series and the instrument data are well correlated, which the maximum correlation coefficient is up to 0.7 at Zhen'an meteorological station, and that of other stations are above 0.6. So the early-spring temperature changes are well reflected by the reconstructed series in this region. Three warm periods, which are from 1715 to 1740, from 1773 to 1804 and from 1893 to 1958, with 26-year, 32-year and 66-year durations respectively, could be detected in the last 300 years, and three cool periods, which are from 1741 to 1772, from 1805 to 1892 and from 1959 to 1992, with 32-year, 88-year and 34-year durations respectively, could also be detected. It is showed that the early-spring temperature in the region increases quickly and decreases slowly, with changes being consistent with the consequences of other researches. Neither the reconstructed series nor the instrument data has significant warming trend before 1992 in the latter part of the 20th century. For the extent of warm or cool period, the early-spring temperature of the west Qinling Mountains is larger than that of the east. The 100-year, 50 to 60-year, 7 to 8-year and 2 to 3-year period cycles can be detected in the reconstructed early-spring temperature series.