Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements

这个合作项目探索了过去40,000年来随着地球从冰期过渡到现代暖期，南极洲周围地区自然气候变化的特征和原因。研究人员将调查南极洲周围的风带如何随着时间的推移改变其强度和位置，并将南大洋的火山爆发和二氧化碳循环作为这段时间内潜在的气候强迫机制。了解过去气候是如何以及为什么自然变化的，对于增进对现代气候变化的理解和对大气中二氧化碳水平较高的未来气候的预测至关重要。研究人员计划沿着南极冰芯1500米的长度进行一系列化学测量，包括主要离子和微量元素浓度，以及微粒(尘埃)浓度和粒度分布。这些测量将：(1)利用硫酸盐和颗粒数据将南极火山爆发记录延长至40,000年；(2)利用尘埃通量数据确定巴塔哥尼亚、新西兰和澳大利亚尘埃源区气候变化的相对时间；(3)利用尘埃大小分布数据调查西风带强度和位置的变化；以及(4)量化随时间推移作为尘埃沉积到南大洋的生物可用痕量金属的通量。这些化学记录也将是创建时间刻度的关键，所有研究人员都将使用这些时间刻度来研究南极核心的记录。该项目将支持三个不同机构的四名研究生和几名本科生，并成为研究人员努力向更广泛的社区传播气候变化科学成果的重点。

This collaborative project explores the signatures and causes of natural climate change in the region surrounding Antarctica over the last 40,000 years as the Earth transitioned from an ice age into the modern warm period. The researchers will investigate how the wind belts that surround Antarctica changed in their strength and position through time, and document explosive volcanic eruptions and CO2 cycling in the Southern Ocean as potential climate forcing mechanisms over this interval. Understanding how and why the climate varied naturally in the past is critical for improving understanding of modern climate change and projections of future climate under higher levels of atmospheric CO2. The investigators plan to conduct a suite of chemical measurements along the 1500m length of the South Pole Ice Core, including major ion and trace element concentrations, and microparticle (dust) concentrations and size distributions. These measurements will (1) extend the South Pole record of explosive volcanic eruptions to 40,000 years using sulfate and particle data; (2) establish the relative timing of climate changes in dust source regions of Patagonia, New Zealand, and Australia using dust flux data; (3) investigate changes in the strength and position of the westerly wind belt using dust size distribution data; and (4) quantify the flux of bioavailable trace metals deposited as dust to the Southern Ocean over time. These chemistry records will also be critical for creating the timescale that will be used by all researchers studying records from the South Pole core. The project will support four graduate students and several undergraduate students across three different institutions, and become a focus of the investigators' efforts to disseminate outcomes of climate change science to the broader community.