基于油松树轮宽度重建河北青龙过去123年平均相对湿度  

Mean relative humidity reconstruction based on the tree-ring width from Chinese pines since 1890 from the Qinglong region, China

作　　者：赵伯阳[1,2] 刘禹[1,3] 宋慧明[1] 李强[1] 

机构地区：[1]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710061 [2]中国科学院大学,北京100049 [3]西安交通大学人居环境与建筑工程学院,西安710049

出　　处：《地球环境学报》2016年第5期509-520,共12页Journal of Earth Environment

基　　金：中国科学院重点部署项目(KZZD-EW-04-01);黄土与第四纪地质国家重点实验室开放基金~~

摘　　要：相对湿度的研究对理解古气候变化有着重要的科学意义,但是目前国内利用树轮资料重建的历史时期相对湿度变化十分有限。本文利用油松树轮宽度重建了河北青龙地区1890—2012年5—7月的平均相对湿度变化,重建序列的方差解释量为39.1%(减少自由度后为38.0%)。重建序列显示出5个湿润期(1895—1899年,1906—1914年,1924—1926年,1950—1955年,1984—2000年)和5个干旱期(1900—1905年,1917—1921年,1927—1949年,1956—1973年,1975—1981年)。重建序列和观测数据均与邻近研究区的PDSI对应良好,表明该序列具有较强的空间代表性,可以反映河北北部地区的平均相对湿度变化情况。本研究表明研究区相对湿度变化不仅受局地气候控制,还可能受到ENSO影响。Background, aim, and scope The study of humidity is essential for better understanding the past climatic variations, however, there were few long-term humidity reconstructions based on tree- ring widths worldwide. Tree-rings have been considered as one of the best known archives in the past climate research field with their high resolution in time and reliability in cross-dating. In our study, a mean relative humidity （MRH5-7） reconstruction curve was carded out using the Chinese pine tree （Pinus tabulaeformis Carr.） from the Qinglong region in northern China. Materials and methods Employing the standard methods sponsored by the International Tree-Ring Data Bank （ITRDB）, we collected 32 tree cores from 16 trees in Qinglong region （40.49°N, 119.53°E, 380 m a.s.l.） during October, 2013. The site has a discontinuous canopy with the sparse trees and the locally dominated tree species is Chinese pine （Pinus tabulaeformis Carr.）. Following the standard dendrochronological procedures, all samples were carefully preprocessed in Laboratory of Tree Ring Research, Institute of Earth Environment, Chinese Academy of Sciences. All 32 cores were cross-dated precisely with the COFECHA program and three tree ring chronologies （STD, RES and ARS chronologies） were carried out with the ARSTAN program. In our case, we reconstruct past relative humidity with RES chronology because RES chronology has a good quality in storing high frequency climate signal. To clarify the climatic conditions in our study area, the meteorological data were extracted from the Qinglong station （40°24＇N, 118°57＇E, 227.5 m a.s.l., records from 1957 to 2012）. PDSI which was extracted from the nearest data grid （41.25°N, 118.75°E） was compared with our RES chronology. To test the spatial representativeness of our reconstruction, spatial correlations between observed relative humidity and reconstructed relative humidity with CRU scPDSI were plotted via KNMI Climate Explorer （http：//climexp.knmi.nl）.We also further

关 键 词：青龙 油松 树轮宽度 相对湿度 重建 

分 类 号：P532[天文地球—古生物学与地层学]