RAPID: Characterizing the Chemical and Physical Signature of the 2015-16 El Nino in the Quelccaya Ice Cap Snow and Ice to Calibrate Past ENSO Reconstructions

该奖项利用资金，在快速反应研究(RAPID)概念的支持下，从秘鲁南部的奎尔卡亚冰盖(QIC)挖掘三个新的雪坑，并收集两个新的十米长的岩芯。将对这些坑和核的样本进行物理和化学分析，以解决以下假设：沉积后特征(如熔融特征)和干沉积痕量物质(如黑碳、尘埃、铵)的浓度升高为过去的厄尔尼诺-南方涛动(ENSO)事件提供新的可靠标志，并有助于量化该事件的强度。这些新的标记还将应用于安第斯山脉南部的其他冰芯，这些冰芯存在于过去40年来收集的扩展热带冰芯档案中。过去厄尔尼诺事件的化学和物理指纹保存在安第斯冰川的冰芯中，特别是QIC，这为量化过去的区域ENSO变化提供了可能性。来自QIC的以前的同位素(德尔塔18氧)记录提供了太平洋海洋表面温度(SST)变化的漫长的年度分辨历史(1800年)。然而，QIC上的德尔塔18-O也受到其他内部变化的气候系统过程的影响(例如，南美季风、ITCZ位置)。因此，需要额外的厄尔尼诺模拟来减少过去厄尔尼诺重建中固有的不确定性，并帮助更准确地预测强度和频率。这项研究可能产生的新数据旨在检验两个假设：1)厄尔尼诺引起的积雪融化和渗流可以在前一年的雪层中识别，并可以根据厄尔尼诺的温度和辐射强迫的强度进行校准；2)生物和蒸发物种的集中和相互联系将得到加强，并在更深的冰层中被探测到，从而揭示过去的厄尔尼诺现象的频率。潜在的更广泛的影响包括实时捕捉现代厄尔尼诺事件的化学和物理特征，这可能有助于评估保存在冰芯中的过去的ENSO变异性，以及评估太阳强迫对气候的作用。这项研究将帮助支持一位职业生涯早期的女科学家，研究成果将以适合公众的短视频片段传播。

This award uses funds, under the auspices of the Rapid Response Research (RAPID) concept, to dig three new snow pits and collect two new ten-meter long cores from the Quelccaya ice cap (QIC) in southern Peru. Samples from these pits and cores will be physically and chemically analyzed to address the hypotheses that post-depositional features (e.g., melt features) and elevated concentrations of dry deposited trace species (e.g., black carbon, dust, ammonium) provide new and reliable markers of past El Niño-Southern Oscillation (ENSO) events and also help facilitate the quantification of the event's intensity. These new markers will be also applied to other ice cores from the southern Andes that exist from extended tropical ice core archives collected over the last forty years.The chemical and physical fingerprints of past El Niño events are preserved in ice cores from Andean glaciers, particularly the QIC, and offer the potential to quantify past regional ENSO variability. Previous isotopic (delta 18-Oxygen) records from the QIC provided a long annually resolved history (1,800 years) of Pacific sea surface temperature (SST) variations. However, delta 18-O on the QIC is also influenced by other internally varying climate system processes (e.g., South American Monsoon, ITCZ position). Consequently, additional El Niño proxies are needed to reduce the uncertainties inherent in past El Niño reconstructions and to help facilitate more accurate projections of intensity and frequency.The new data that could result from the research is aimed at testing two hypotheses: 1) the snow melt and percolation induced by El Niño is identifiable in the prior year's snow layer and can be calibrated to the El Niño's strength in terms of temperature and radiative forcing; and 2) the concentration and co-association of biogenic and evaporitic species will be enhanced and detectable deeper in the ice and thereby reveal past El Niño frequency.The potential broader impacts include capturing the chemical and physical signatures of a modern El Niño event in real time that could help evaluate past ENSO variability preserved in ice cores as well as assessing the role of solar forcing in climate. The research will help support an early career female scientist and the research results will be disseminated in short video segments appropriate for the public.