Tree-Ring Latewood Width Based July–August SPEI Reconstruction in South China since 1888 and Its Possible Connection with ENSO

作     者：Yesi ZHAO Jiangfeng SHI Shiyuan SHI Jian YU Huayu LU Yesi ZHAO;Jiangfeng SHI;Shiyuan SHI;Jian YU;Huayu LU

作者机构：Ministry of Education Key Laboratory for Coast and Island Development School of Geographic and Oceanographic Sciences Nanjing University College of Landscape Architecture Jiangsu Vocational College of Agriculture and Forestry 

出 版 物：《Journal of Meteorological Research》 (气象学报（英文版）)

年 卷 期：2017年第31卷第1期

页      面：39-48页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：Supported by the National Natural Science Foundation of China(41271210) Global Change Program(2016YFA0600503) Priority Academic Program Development of Jiangsu Higher Education Institutions Jiangsu Collaborative Innovation Center for Climate Change 

主　　题：tree rings adjusted latewood width SPEI South China 

摘      要：Our understanding of the long-term hydroclimate variations in South China is prohibited by the shortness of me- teorological records. Paleoclimatic proxies, such as tree-rings, can be pursued to extend the meteorological records back for centuries to help us better understand hydroclimatic conditions. In this study, we reconstructed the July--Au- gust standardized precipitafio^evapotranspiration index （SPEIjut Aug） based on a newly developed 127-yr adjusted latewood width chronology from Tsuga longibracteata, South China. The chronology explained 40% of the actual SPEIjul Aug variance in the period 1953-2014. The reconstructed SPEIjuI Aug can represent large-scale July-August SPEI variations over South China, including northern Guangxi, Hunan, and Guizhou provinces. From the perspec- tive of the past 127 years, the extreme summer drought in 2013 was not unusual because more extreme drought events occurred in the first half of the 20th century. A significant 2.0-3.6-yr hydroclimatic cycle existed in the recon- struction, which indicated that the SPEIjulug might be driven by El Nifio-Southern Oscillation （ENSO）. We further checked the time-dependency of the relationship between SPEIJuI_Aug and ENSO and found that it was unstable. Their relationship was weak before the 1950s, became significant from the 1950s to early 1990s, and then dropped to be weak again and even out of phase since the early 1990s, which may be attributable to the significant westward exten- sion of the western Pacific subtropical high.