Collaborative Research: A Southern Hemispheric Perspective on Holocene Climate Variability Based on Mountain Glacial Chronologies

该奖项是根据2009年美国复苏和再投资法案(公法111-5)资助的。该小组将测试有关全新世期间南半球气候与北半球气候的时间和空间变异性如何与北半球相比的假说。这项研究将通过提供有关南半球气候变化的视角，帮助解决古气候的驱动因素。利用最近的分析进展，该小组使用10Be测量来直接测定全新世中期到晚期的冰雹的年龄。这些年龄提供了一个新的视角，特别是当与其他替代记录相结合时，提供了关于南方陆地大气气候变异性的新视角。重点放在南安第斯山脉的陆冰覆盖历史上，那里的冰冻圈对大气温度和降水的变化特别敏感。这一新的年表说明了巴塔哥尼亚和南半球在全新世中后期的陆冰变化以及20/21世纪变化的背景。巴塔哥尼亚位于全球的一个关键地区，可以洞察过去大气气候变异性的变化。它是受极地和中纬度气候影响的地区唯一介于~46°S和南极之间的主要大陆。现代人类文明是在全新世气候变异性的背景下发展起来的，了解这种变异性的原因一直是古气候学最重要的目标之一。正如政府间气候变化专门委员会指出的那样，由于缺乏过时的古气候记录，人们对南半球气候的了解，特别是过去2000年的气候，受到了“严重限制”。这项拟议的研究通过使用一种新的方法来确定晚全新世冰雹的年代，有助于改变我们对南半球古气候的理解。这项技术可以对由于缺乏有机物而难以确定日期的序列进行研究。该项目还提高了我们对20/21世纪冰川变化的理解，冰川变化可能在两个半球之间有所不同。该项目协调冰川地质学和地质年代学方面的专门知识，以及冰川气候模型和古生态学专家之间的合作。更广泛的影响包括加强美国、英国、智利、阿根廷和新西兰大学之间的关系。国际合作涉及几位相对接近职业生涯开始阶段的科学家。私人投资者都积极参与教育和外联活动，这涉及到世界上最繁忙的国家公园之一的冰川历史。结果将在开放的数据集上获得，并在公园的显示器上显示。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The group will test hypotheses concerning how temporal and spatial variability of Southern Hemisphere climate compared with the Northern Hemisphere during the Holocene. This research will help resolve drivers of paleoclimate by providing a perspective on Southern Hemisphere climate changes. Using recent analytic advances, the group uses 10Be measurements to directly date mid- to late Holocene moraines. These ages provide a new perspective, especially when combined with other proxy records, on Southern terrestrial-atmosphere climate variability. The focus is on the history of land ice-cover in the southern Andes, where the cryosphere is particularly sensitive to changes in atmospheric temperature and precipitation.This new chronology illustrates changes in land ice in Patagonia and the Southern Hemisphere during the mid- to late Holocene and the context for 20th/21st century changes. Patagonia is in a key area of the globe to provide insight into past changes in atmospheric climate variability. It is the only major landmass between ~46°S and Antarctica in an area affected by both polar and middle latitude climate regimes.Modern human civilization has developed against the backdrop of Holocene climate variability, and one of the most important goals in paleoclimatology has been to understand the causes of this variability. As pointed out by the IPCC, knowledge of Southern Hemisphere climate, especially over the last 2000 years, is 'severely limited' by the lack of dated paleoclimate records. The proposed research helps transform our understanding of Southern Hemisphere paleoclimate by using a new approach to date Late Holocene moraines. This technique allows study of sequences that have been difficult to date because of a lack of organic matter. This project also improves our understanding of 20th/21st century changes in glaciers, which may be different between the hemispheres. The project coordinates expertise in glacial geology and geochronology and collaboration between experts in glacier-climate modeling and paleoecology. Broader impacts include strengthening the relations between universities in the U.S., UK, Chile, Argentina, and New Zealand. The international collaborations involve several scientists relatively close to the start of their careers. The PIs are all actively engaged in education and outreach, which involves the glacial history of one of the busiest national parks in the world. The results will be avilable in open datasets, and on displays in the parks.