A new method for calibrating a boron isotope paleo-pH proxy using massive Porites corals
A new method for calibrating a boron isotope paleo-pH proxy using massive Porites corals
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DOI：
10.1002/2015gc005975
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发表时间：
2015-09-01
影响因子：
3.5
通讯作者：
Suzuki, Atsushi
中科院分区：
文献类型：
--
作者：
Kubota, Kaoru;Yokoyama, Yusuke;Suzuki, Atsushi
海洋生物碳酸盐的硼同位素比值（δ B-11）可以重建海水的pH和pCO（2），并可能重建大气中的CO2浓度。迄今为止，已经通过培养实验提出了Δ B-11-pHSW校准，其中在人工酸化的海水下培养钙化生物。然而，在石珊瑚，重建的pH值，使用基于文化的校准不同意与实际观测海水CO2化学。因此，需要另一种方法来建立更可靠的校准方法。在这项研究中，我们建立了基于现场的校准Chichijima和塔希提岛，都位于亚热带环流，地表海水接近CO2平衡。我们提出了一种新的方法来校准δ B-11-pH，其中将大规模滨珊瑚的长期δ B-11变化与pH下降趋势（即，海洋酸化），这是自工业革命以来发生的。这种校准将提供一个新的途径，在不同的设置，如涌升区，珊瑚礁和沿海地区，使用珊瑚三角洲B-11研究海水CO2化学。
The boron isotope ratio (delta B-11) of marine biogenic carbonates can reconstruct pH and pCO(2) of seawater, and potentially CO2 concentration in the atmosphere. To date, delta B-11-pHSW calibration has been proposed via culturing experiments, where calcifying organisms are cultured under artificially acidified seawater. However, in scleractinian corals, reconstructed pH values using culture-based calibrations do not agree well with actual observations of seawater CO2 chemistry. Thus, another approach is needed to establish a more reliable calibration method. In this study, we established field-based calibrations for Chichijima and Tahiti, both located in subtropical gyres where surface seawater is close to CO2 equilibrium. We suggest a new approach to calibration of delta B-11-pH in which the long-term delta B-11 variation of massive Porites corals is compared with the decreasing pH trend (i.e., ocean acidification) that has occurred since the Industrial Revolution. This calibration will offer a new avenue for studying seawater CO2 chemistry using coral delta B-11 in diverse settings, such as upwelling regions, coral reefs, and coastal areas.