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4万年地球从冰河期过渡到现代暖期期间，南极洲周围地区自然气候变化的特征和原因。研究人员将调查围绕南极洲的风带是如何随着时间的推移在强度和位置上发生变化的，并记录下在这段时间内，火山爆发和南大洋的二氧化碳循环是潜在的气候强迫机制。了解过去气候自然变化的方式和原因，对于提高对现代气候变化的认识以及在更高大气二氧化碳水平下对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的浓度，以及微粒（尘埃）的浓度和大小分布。这些测量将(1)利用硫酸盐和颗粒数据将南极火山爆发的记录延长到4万年；(2)利用沙尘通量数据建立了巴塔哥尼亚、新西兰和澳大利亚沙尘源区气候变化的相对时序；(3)利用沙尘粒度分布资料研究西风带的强度和位置变化；(4)量化以尘埃形式沉积到南大洋的生物可利用微量金属随时间的通量。这些化学记录对于创建所有研究南极核心记录的研究人员都将使用的时间尺度也至关重要。该项目将支持来自三个不同机构的四名研究生和几名本科生，并成为研究人员向更广泛的社区传播气候变化科学成果的努力的焦点。

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.