P2C2: Signatures of the Toba Super-eruption in Borneo Stalagmites

该奖项支持收集来自婆罗洲北方的Gunung Mulu国家公园的年代久远的石笋，以生成高分辨率大气火山负荷的成对重建，这是通过火山灰和挥发物的微尺度分析和石笋三角洲氧-18同位素（δ-18 O）确定的，作为水文气候的代理。 大规模火山爆发通过硫酸盐气溶胶的辐射效应对气候产生显著的冷却效应，因此是定量数据-模型相互比较的关键目标。 作为过去200万年来最大的一次喷发，位于印度尼西亚苏门答腊岛的多巴超级火山口在大约74，000年前喷发时，从东非到南海撒下了厚厚的火山灰层。火山爆发的气候属性是复杂的千年尺度的气候突变事件，在时间上与火山爆发密切相关。 数值气候模型模拟证实，多巴火山规模的喷发会对全球气候产生重大影响，尽管其辐射影响的规模和持续时间存在很大的不确定性。利用这些数据集，研究人员的目标是确定多巴灰负荷相对于石笋三角洲-18 O异常的相对时间，这些异常表明区域水文气候影响。他们将使用现有的一套模拟大型火山爆发的模拟结果，将他们的水文气候重建与配备水同位素的NASA/GISS ModelE 2-R的输出进行比较。石笋在世界许多地区提供了非常好的日期，高分辨率的气候重建，但只有少数研究调查了它们作为火山强迫历史档案的用途。婆罗洲石笋代表了一个机会，追求这种绝对过时的重建，并直接比较它们的水文气候重建在一个非常大的爆发的时间范围。 该奖项在气候科学方面进行了强有力的持续公众宣传工作，例如组织了一次关于“气候如何运作”的公共研讨会，涉及当地高中科学课程，并为参加者提供夏季研究实习机会，以及率先为Gunung Mulu石笋建立永久档案，以确保其他科学家获得宝贵的样本。

This award supports the collection of well-dated stalagmites from the Gunung Mulu National Park in northern Borneo to generate paired reconstructions of high resolution atmospheric volcanic loading, as determined by micro-scale analyses of volcanic ash and volatiles, and stalagmite delta oxygen-18 isotopes (delta-18O), as a proxy for hydroclimate. Large volcanic eruptions have a significant cooling effect on climate through the radiative effects of sulfate aerosols and, as such, represent key targets for a quantitative data-model inter-comparison. As the largest eruption of the last 2 million years, the Toba super-caldera, located on the island of Sumatra, Indonesia, spread a thick layer of ash from East Africa to the South China Sea when it erupted roughly 74,000 years ago. The eruption's climatic attribution is complicated by a millennial-scale abrupt climate change event that is closely associated in time with the eruption. Numerical climate model simulations confirm that an eruption of Toba's size would have had significant impacts on global climate despite significant uncertainties regarding the size and duration its radiative effects. With these datasets, the researchers aim to determine the relative timing of Toba ash loading with respect to stalagmite delta-18O anomalies indicative of regional hydroclimate impacts. They will compare their hydro-climate reconstructions with output from the water isotope-equipped NASA/GISS ModelE2-R using an existing suite of simulations forced with large volcanic eruptions.Stalagmites have provided exceptionally well-dated, high-resolution reconstructions of climate in many areas of the world, yet only a handful of studies have investigated their use as archives of volcanic forcing histories. The Borneo stalagmites represent an opportunity to pursue such absolutely-dated reconstructions and to directly compare them to reconstructions of hydro-climate across the time horizon of an exceptionally large eruption. This award carries with it strong ongoing public outreach efforts in climate science such as organizing a public symposium on "How Climate Works" involving local high school science classes and offering summer research internships to those that attend as well as spearheading an initiative to establish a permanent archive for the Gunung Mulu stalagmites to ensure access to the valuable samples for other scientists.