利用树轮宽度重建黄河源区1618—2009年5—6月最高气温

Using Tree-Ring Width to Reconstruct the Maximum Air Temperature of Yellow River Source Region in May-June over 1618-2009

利用采集自青海省雪山乡的祁连圆柏建立树轮宽度标准年表,将标准年表与黄河源区内4个气象站各气象要素作相关分析,结果显示整个源区5—6月最高气温与标准年表相关性最显著,相关系数为-0.65。根据相关分析结果,重建了黄河源区1618—2009年5—6月最高气温距平序列,重建方程经过逐一剔除检验,方差解释量达42.2%,具有一定的可靠性。重建序列在近400年间先后经历了8个较暖时间段和8个较冷时间段,暖期时段有1644—1656、1727—1746、1786—1797、1817—1835、1860—1885、1916—1934、1952—1968和1992—2005年,冷期的时段分别为1632—1643、1657—1696、1747—1764、1798—1816、1836—1859、1898—1915、1935—1951和1969—1991年。对比本次重建序列与杂多、青藏高原东部以及长江源的气温重建序列,发现以上序列在公共时段变化趋势一致,另外,一些文献和历史记载也证实了此次重建的可靠性。

Tree-ring width standardized chronology （STD） was created by Sabinaprzewalskii Kom which collected in Xueshan Township of Qinghai Province. Analyzing the correlation between STD and climate factors of 4 meteorological stations in the source region of Yellow River. The results showed that STD was significantly correlated with maximum air temperature of the whole area in May-June and the correlation coefficient was -0.65. According to the results above, the maximum air temperature anomalies sequence in May-June of Yellow River source region during 1618-2009 was reconstructed. The reconstructed function embodied a certain degree of reliability and stability after level-one-out test and the explain variance reached 42.2%. There were 8 warm periods and 8 cold periods in the reconstructed maximum air temperature sequence over the past 400 years. Warm periods included 1644-1656, 1727-1746, 1786-1797, 1817-1835, 1860-1885, 1916-1934, 1952-1968 and 1992-2005, while cold periods contained 1632-1643, 1657-1696, 1747-1764, 1798-1816, 1836-1859, 1898- 1915, 1935-1951 and 1969-1991. Comparing the reconstructed sequence in this study with temperature series reconstructed in Zadoi, on northeastern Tibetan Plateau and in the source region of Yangtze River, their trends were basically the same in common years. In addition, the reliability of this reconstructed sequence could be confirmed by some documents and historical records.