Comparison of alkenone estimates with other paleotemperature proxies
Comparison of alkenone estimates with other paleotemperature proxies
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DOI：
10.1029/2000gc000050
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发表时间：
2001-01
期刊：
影响因子：
3.7
通讯作者：
E. Bard
中科院分区：
文献类型：
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作者：
E. Bard
在某种程度上，由于信号保存问题和其他环境变量的扰动，所有的海表温度（SST）代用指标都存在不确定性。然而，多代理重建是合理的，因为大多数偏差原则上应该抵消，因为它们是特定的生物群体和/或分析的化学物种。这种多代理策略已被证明是至关重要的校准这些代理，也是有用的，在评估downcore配置文件。到目前为止，只有十几个深海岩心可以直接将基于烯酮的SST与其他古温度记录进行比较。从这一仍然有限的数据组中可以大致看出，低纬度和中纬度的变化幅度是一致的。观察到的少数差异表明，基于烯酮的温度与基于Mg/Ca比的温度比通过有孔虫分布的统计分析获得的温度更具可比性。更系统的差异，指出在较高的纬度，在那里的烯酮表明温暖的温度在冰期比基于有孔虫或硅藻的传递函数。有几个原因被用来解决不匹配的问题，但在决定哪种温度变化最准确之前，还需要更多的“地面实况”工作。
To a certain degree, all sea surface temperature (SST) proxies suffer from uncertainty due to signal preservation problems and to perturbations by other environmental variables. However, a multiproxy reconstruction is justified because most biases should, in principle, cancel out as they are specific to the biological groups and/or to the analyzed chemical species. Such a multiproxy strategy has proven crucial for calibrating these proxies and is also useful in assessing downcore profiles. Until now there have been only a dozen deep‐sea cores where it is possible to compare directly alkenone‐based SSTs with other paleotemperature records. From this still limited data set the broad picture is of general agreement for the amplitude of changes at low and middle latitudes. The few observed discrepancies suggest that alkenone‐based temperatures are more comparable to those based on Mg/Ca ratios than those obtained through statistical analysis of the foraminiferal distribution. More systematic differences are noted at higher latitudes, where alkenones indicate warmer temperatures during the glacial period than transfer functions based on foraminifera or diatoms. Several reasons have been invoked to resolve the mismatch, but more “ground truthing” work is needed before deciding which temperature changes are the most accurate.