Culture experiments on the environmental controls of trace metal ratios (Mg/Ca, B/Ca, U/Ca) recorded in calcareous tests of bipolar deep-sea benthic foraminifera

极地海洋是我们最重要的气候放大器：首先，极地深水沃茨的产生驱动了全球温盐输送带，从而驱动了气候。第二，南极深水在冰川时期是，有争议的仍然是，最大的海洋大气二氧化碳汇。采用有效的和可靠的物理和地球化学性质变化的替代指标，对评估冰川-间冰期变化、两极深水的现代和未来变化至关重要。在这方面，常见的方法是分析有孔虫试验中记录的微量金属（Mg/Ca、U/Ca、B/Ca）比值，以估计钙化温度、碱度、碳酸根离子饱和度和pH值。然而，北极和南大洋深海底栖有孔虫校准曲线缺乏岩心顶部样品或培养实验的约束。新开发的高压水族馆最近促进了我们最值得信赖的古深水记录仪Fontbotia wuellerstorfi和Uvigerina peregrina的首次有效培养（生产后代）。在不同的实验装置中，将使用相同的设施在不同的温度和具有不同碳酸盐化学性质的沃茨中培养这些有孔虫和相关物种，以建立两个极地海洋的第一个物种特定的痕量金属校准曲线。对两大洋150多个核心站点的核心顶部分析将验证实验结果。

The Polar Oceans are our most important climate amplifiers: First, the production of polar deep waters drives the Global Thermohaline Conveyer Belt, and thus, climate. Second, the Antarctic deep water during glacial time was, disputably still is, the largest marine sink of atmospheric CO2. Employment of effective and fossilisable proxies on changes in the physical and geochemical properties is essential to assess glacial-interglacial variabilities, modern and future changes in bipolar deep-waters. In this respect, analyses on trace metal (Mg/Ca, U/Ca, B/Ca) ratios recorded in tests of foraminifers to estimate calcification temperatures, alkalinity, carbonate ion saturation, and pH are common methods. However, for the Arctic and Southern Ocean deep-sea benthic foraminifera calibration curves constrained by either core-top samples or culture experiments are lacking. Newly developed high-pressure aquaria have recently facilitated the first efficient cultivation (producing offspring) of our most trusted palaeodeep-water recorders Fontbotia wuellerstorfi and Uvigerina peregrina. In different experimental set-ups the same facilities will be used to cultivate these foraminifera and associated species at different temperatures and in waters with different carbonate chemistries to establish the first species-specific trace metal calibration curves for both Polar Oceans. Core top analyses on more than 150 core sites from both oceans will verify the experimental results.