基于多点树轮序列的1768—2006年甘肃降水量变化  

Variation of Annual Precipitation during 1768-2006 in Gansu Inferred from Multi-site Tree-ring Chronologies

作　　者：陈峰[1,2] 魏文寿[1] 袁玉江[1] 喻树龙[1] 尚华明[1] 张同文[1] 张瑞波[1] 王慧琴[1] 秦莉[1] 

机构地区：[1]中国气象局乌鲁木齐沙漠气象研究所新疆树木年轮生态实验室/中国气象局树木年轮理化研究重点开放实验室,新疆乌鲁木齐830002 [2]兰州大学西部环境教育部重点实验室/西部环境与气候变化研究院,甘肃兰州730000

出　　处：《中国沙漠》2013年第5期1520-1526,共7页Journal of Desert Research

基　　金：科技部公益性行业(气象)科研专项项目(GYHY200806011);科技部科技基础性工作专项项目(2007FY220200);中央级基本科研业务费项目(IDM201105);中国沙漠气象科学研究基金项目(SQJ2010011)资助

摘　　要：选择12个树木年轮宽度年表和28个气象站的降水量资料分别建立甘肃树轮宽度场和降水量场。树轮气候响应分析发现树轮宽度场第一主成分与甘肃28个气象站上年7月至当年6月降水量第一主成分有较好相关性,相关系数为0.580(p<0.001)。利用线性回归模型重建甘肃上年7月至当年6月降水量第一主成分,方差解释量为33.6%(1961—2006年)。在1768—2006年期间甘肃有11个降水量较多的时期(高于多年平均值)和11个降水量较少的时期(低于多年平均值),分别反映了东亚夏季风较强和较弱的时期。同时,降水量重建序列的低值与西北地区极端干旱历史事件有着良好的一致性。空间相关分析表明该重建序列能够表征甘肃大范围的降水量变化,与实测降水量资料的第一主成分空间变化较为一致。多窗谱分析发现,甘肃降水量具有36.6年(95%)、11.2年(95%)、4.8年(95%)、3.4年(95%)、3.1年(95%)、2.6年(95%)和2.4年(99%)的周期变化。甘肃降水量与亚洲中纬度西风区、季风区树轮降水量序列之间存在一定的关联性,甘肃降水量变化与季风降水量的关联要大于与西风区降水量。The 12 tree-ring width chronologies and precipitation data from 28 meteorological stations were selected to build the tree-ring field and precipitation field in Gansu. The climate-response analysis showed the first eigenvector of the tree-ring field had a good correlation （r = 0. 58） with precipitation from July to next June in Gansu. Based on the first eigenvector of the tree-ring field in Gansu, we reconstructed precipi- tation from July to next June during 1768-2006 in Gansu. The climate/tree-growth model accounted for 33.6% of the observed precipitation variance during 1961-2006. Eleven dry period （precipitation values higher than the average value of reconstructed precipitation data） and eleven wet period （precipitation val- ues lower than the average value of reconstructed precipitation data） was found during 1768-2006, which reflected the strong-weak changes of the East Asian Summer Monsoon. The low values of reconstructed pre- cipitation data were in substantial agreement with drought events in the historical archives in Gansu. Spatial correlation analyses revealed that the reconstructed precipitation data contained a strong regional precipitati- on signal in Gansu, which was affected by East Asian Summer Monsoon. The spectral analysis by multi-taper method indicated the existence of 36.6 years （95%）, 11.2 years （95%）, 4.8 years （95%）, 3.4 years （95%）, 3.1 years （95%）, 2.6 years （95%）, 2.4 years （99%） cycles of the reconstructed precipitation variation. The comparison of reconstructed precipitation data in Gansu, monsoon region and the Westerly area of the mid-latitude Asia revealed that there were some good correlations among them, and the East Asi- an Summer Monsoon had the greater effects on the precipitation in Gansu than the Westerlies.

关 键 词：甘肃 树木年轮 降水量重建 西风 东亚夏季风 

分 类 号：P467[天文地球—大气科学及气象学]