摘要
昆仑山北坡西部山区是树木年轮气候研究的薄弱区域。本文在位于公格尔山北坡的喀山河流域山区采集了雪岭云杉的树芯标本,分析了树轮宽度标准年表对塔里木盆地西缘气候要素的响应关系,发现了该区域的树木径向生长主要受水分条件限制,标准年表与塔里木盆地西缘6站平均上年7月至当年6月降水量的相关系数达到0.692(P<0.001)。利用树轮宽度年表与降水量之间的线性转换方程重建了塔里木盆地西缘1715—2014年降水量序列,转换方程的方差解释量为48.0%,且稳定可信。重建的降水序列记录了21个极端干旱年和21个极端湿润年。对重建序列进行31年滑动快速傅里叶变换(FFT)分析发现,塔里木盆地过去300年出现了5个偏干阶段1725—1750、1777—1806、1821—1843、1854—1887和1911—1990年)和6个偏湿阶段(1715—1724、1751—1776、1807—1820、1844—1853、1888—1910和1991—2014年)。20世纪80年代中期以来增湿趋势明显,且仍在持续。塔里木盆地西缘干湿变化的韵律与相邻区域的树木年轮水分记录是一致的,几个显著的干湿阶段均能较好地对应,只是其变化幅度和持续的时间存在差异。
As an optimum region, for dendroclimatological research, no study has yet reconstructed precipitation variability on the northern slope of western Kunlun Mountains in a long-term context. Based on tree-ring cores of Picea schrenkiana which collected from the Kashan River valley, tree-ring width chronology was developed. The correlation analysis between tree-ring width standard chronologies and the climatic factors reveals that the dominant control factor of radial growth of Picea schrenkiana is moisture（precipitation）. The highest correlation coefficient（0.692）is found between ring width index and annual（July-June）precipitation. The linear transfer function is used to reconstruct the annual precipitation for the western edge of Tarim basin during 1715-2014. The leave-one-out verification test revealed that the model is stable. 21 extremely arid and 21 extremely wet years were found in the reconstructed precipitation series. The precipitation reconstruction also revealed that five drought periods （1725-1750, 1777-1806, 1821-1843, 1854-1887 and 1911-1990）and six wet periods （1715-1724, 1751-1776, 1807-1820, 1844-1853, 1888-1910 and 1991-2014）. The wetting trend is found since the 1980s. Our reconstruction agreed in general with other tree ring-based precipitation/drought reconstructions from nearby regions on a decadal timescale.
出处
《沙漠与绿洲气象》
2016年第2期9-17,共9页
Desert and Oasis Meteorology
基金
自治区重点实验室专项(2014KL017)
气象行业专项(GYHY201206014)
国家科技支撑计划课题(2012BAC23B01)
国家自然科学基金(41205124,41271098)共同资助
