Decadal cyclicity of regional mid‐Holocene precipitation: Evidence from Dominican coral proxies
Decadal cyclicity of regional mid‐Holocene precipitation: Evidence from Dominican coral proxies
复制标题
区域全新世中期降水的年代际循环：来自多米尼加珊瑚代理的证据
DOI：
10.1029/2005pa001166
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
P. Swart
中科院分区：
文献类型：
--
作者：
L. Greer;P. Swart
[1]对多米尼加共和国4个全新世Montastraea sp.和Siderastrea sp.珊瑚骨骼标本的稳定碳（δ 13 C）和氧（δ 18 O）同位素组成进行了分析，以研究区域降水的年代尺度波动。这些标本的长度从47岁到197岁不等，年龄从7.2万年到5.2万年不等。全新世Enriquillo山谷珊瑚骨骼的δ 13 C和δ 18 O的振荡似乎以15-20年的一致频率发生。对于一个珊瑚（106 ka），这种十年到几十年的变化模式是统计上显着的。稳定同位素变化的年代际到年代际模式可能代表热带辐合带（ITCZ）中全新世迁移的周期性波动，或该地区的水文地质受热带风暴和飓风通道波动的影响。区域温度被认为只是这些珊瑚的δ 18 O值的次要控制因素。然而，ITCZ迁移和/或振荡风暴频率在这个网站可能最终反映在更大的热带北大西洋海面温度的十年尺度模式。在这项研究中所代表的气候变率的长度和分辨率表明，在整个全新世中期，大西洋气候波动的持续十年到几十年的模式是无法区分的观察到的历史气候。
[1] The stable carbon (δ13C) and oxygen (δ18O) isotopic compositions of four Holocene specimens of Montastraea sp. and Siderastrea sp. coral skeletons from the Dominican Republic were analyzed to examine decadal-scale fluctuations in regional precipitation. The specimens range in length from 47 to 197 years individually and range in age from ∼7.2 to 5.2 kyr. Oscillations in the δ13C and δ18O of coral skeletons from the Holocene Enriquillo Valley occur with a seemingly consistent frequency of 15–20 years. For one coral (∼6 ka) this decadal to multidecadal mode of variability is statistically significant. The decadal to multidecadal mode of stable isotopic variability may represent cyclic fluctuations in mid-Holocene migration of the Intertropical Convergence Zone (ITCZ) or in the hydrogeology of the region as governed by fluctuations in the passage of tropical storms and hurricanes. Regional temperature is believed to act as only a secondary control on the δ18O values of these corals. However, ITCZ migration and/or oscillations in storm frequency at this site may ultimately reflect decadal-scale patterns in greater tropical North Atlantic sea surface temperatures. The length and resolution of climate variability represented in this study indicate a persistent decadal to multidecadal mode of Atlantic climate fluctuation throughout the mid-Holocene that is indistinguishable from observed historical climate.