A model-based test of accuracy of seawater oxygen isotope ratio record derived from a coral dual proxy method at southeastern Luzon Island, the Philippines
A model-based test of accuracy of seawater oxygen isotope ratio record derived from a coral dual proxy method at southeastern Luzon Island, the Philippines
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基于模型的菲律宾吕宋岛东南部珊瑚双代理法海水氧同位素比记录准确性测试
DOI：
10.1002/jgrg.20074
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
and H. Kawahata
中科院分区：
文献类型：
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作者：
Liu;G.;K. Kojima;K. Yoshimura;T. Okai;A. Suzuki;T. Oki;F. Siringan;M. Yoneda;and H. Kawahata
海水氧同位素比值（δ 18 Osw）是反映热带地区过去水文气候条件的重要指标。在这项研究中，我们应用一个双重代理的方法，使用δ 18 O和Sr/Ca的珊瑚骨骼估计δ 18 Osw。由于缺乏δ 18 Osw的长期连续观测数据，因此使用与历史表面大气数据相关的简化海洋表面一维箱模型与珊瑚衍生的δ 18 Osw记录进行比较。大气数据包括降水和蒸发值，以及来自全球同位素再分析数据的δ 18 O组成。模式成功地再现了1979-2001年菲律宾吕宋岛东南部δ 18 Oswat的年代际时间序列（r= 0.57，p < 0.01）。结果表明，珊瑚记录是一个准确的指标，在现场的水文循环变化。繁殖和珊瑚记录在雨季（12月至2月）之间的差异可能是由于季节性变化的混合层和上升流的深度，因为这些因素没有考虑到在模型中。在旱季（4 - 6月），珊瑚的δ 18 OSW与珊瑚记录吻合较好，这意味着在一年中的这个时候，用珊瑚双代用指标法估算的δ 18 OSW更可靠。
The oxygen isotope ratio in seawater (δ18Osw) is an important indicator of past hydroclimatic conditions in the tropics. In this study, we apply a dual proxy approach using δ18O and Sr/Ca in coral skeletons to estimate δ18Osw. Due to a lack of long‐term continuous observational data for δ18Osw, a simplified one‐dimensional box model of the ocean surface associated with historical surface atmospheric data is used for comparison with coral‐derived δ18Oswrecord. The atmospheric data consist of the precipitation and evaporation values, together with their δ18O compositions from the global isotope reanalysis data. The model successfully reproduces a multidecadal time series for δ18Oswat southeastern Luzon Island, the Philippines, for the period 1979–2001 (r= 0.57,p< 0.01). The result suggests that the coral records are an accurate indicator of hydrological cycle changes at the site. A discrepancy between the reproduction and the coral record in the wet season (December–February) may be caused by seasonal variation in the depth of the mixed layer and upwelling, since these factors are not accounted for in the model. The reproduction is in good agreement with the coral records in the dry season (April–June), implying that δ18Oswestimated using the coral dual proxy method is more robust at this time of year.