RII Track-4: NSF: Building Linkages: Assessing the Importance of Terrestrial Climate in Deglacial Ice Sheet Dynamics through Collaborative Research Capacity Building

随着世界气候继续变暖，了解格陵兰和南极冰盖融化将如何导致海平面上升变得越来越重要。具体地说，随着冰盖在陆地上的消退，了解当地气候对冰盖边缘融化的作用变得至关重要。因此，这个项目的目标有三个。最初，研究人员将重建新英格兰过去气候(温度和降水)的记录。重建的过去气候将来自大约13,000年前，当时一个大冰盖在类似的变暖条件下正在退缩。为了实现这一目标，研究小组将分析遗留在湖泊沉积物中的植物和细菌的有机分子，这些有机分子的形态和组成反映了过去温度和降水的变化。其次，PI将把这些新的高分辨率气候记录与现有的冰盖边缘活动变化记录进行比较，以阐明当地气候对大冰盖融化和消退的作用。了解当地气候如何影响过去冰盖的融化，将有助于预测持续的气候变化将如何推动格陵兰和南极冰盖的融化。更好地了解和预测冰盖融化对海平面上升的贡献，对于帮助世界各地的沿海地区做好准备并减轻相关后果至关重要。该项目的第三个也是最终目标包括一个小型农村机构的能力建设和本科生的研究经验，帮助培养下一代地球和气候科学家。这个研究基础设施改进Track-4 EPSCoR研究人员(RII Track-4：NSF)项目将为普利茅斯州立大学的一名教师提供奖学金，并为一名本科生提供培训。这项工作将与科罗拉多博尔德大学的研究人员合作进行。在未来变暖的条件下，世界冰盖预计将继续缩小，可能会产生广泛和灾难性的全球后果。然而，陆地气候变化对冰盖波动的作用，特别是在冰缘消退期间，仍然知之甚少。虽然已知冰盖质量平衡和冰动力学的变化会在千年到数千年的时间尺度上驱动冰缘波动，但据推测，更局部的陆地气候在较短的时间尺度冰缘波动中发挥了重要作用。更好地了解当地气候对过去冰缘行为的影响，对于理解现代冰盖边缘将如何应对持续的气候变化是必要的。这位研究人员将试验产生新的高分辨率温度和水气候记录，此前美国东北部在最后一次冰盛期之后被劳伦蒂德冰盖消融。温度和水文气候将分别使用分枝甘油二烷基甘油四醚(BrGDGTS)和保存下来的树叶蜡降水的氢同位素组成(δ2H)重建，使用来自新英格兰中部的沉积物岩心(手头和待收集的)。这位研究人员将通过延长访问科罗拉多大学博尔德大学的两个实验室设施，并与他们的PI和工作人员合作来实现这一点。这些新记录将与现有的北美Varve年表进行比较，该年表包含LIS退缩和研究区域冰缘波动的详细记录。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

As the world’s climate continues to warm, it is increasingly important to understand how the melting Greenland and Antarctic ice sheets will contribute to sea level rise. Specifically, as the ice sheets retreat over land, it becomes imperative to understand the role local climate has on the melting of ice sheet margins. Thus, the goals of this project are threefold. Initially, the researcher will reconstruct records of past climate (temperature and precipitation) in New England. The reconstructed past climate will be from approximately 13,000 years ago when a large ice sheet was retreating under analogous warming conditions. To accomplish this, the research team will analyze organic molecules from plants and bacteria left behind in lake sediments and whose form and composition reflect past changes in temperature and precipitation. Second, the PI will compare these new high-resolution climate records to existing records of changes in ice sheet margin activity to elucidate the role of local climate on the melting and retreat of large ice sheets. Understanding how local climate impacted the melting of past ice sheets will help forecast how continued climate change will drive melting of the Greenland and Antarctic ice sheets. Better understanding and predictions of melting ice sheet contributions to sea level rise are vital in helping coastal areas worldwide to prepare for and mitigate associated consequences. The third and final goal of the project includes capacity building at a small rural institution and research experience for undergraduate students, helping to prepare the next generation of earth and climate scientists.This Research Infrastructure Improvement Track-4 EPSCoR Research Fellows (RII Track-4:NSF) project would provide a fellowship to a Teaching Faculty member and training for an undergraduate student at Plymouth State University. This work would be conducted in collaboration with researchers at the University of Colorado Boulder. The world's ice sheets are projected to continue to shrink under future warming conditions, with potentially wide-ranging and catastrophic global consequences. However, the role of terrestrial climate change on ice sheet fluctuations, especially during times of ice margin retreat, remains poorly understood. While changes in ice sheet mass balance and ice dynamics are known to drive ice-margin fluctuations on millennial to multi-millennial timescales, it is hypothesized that more local, terrestrial climate plays a significant role in shorter timescale ice margin fluctuations. A better understanding of the impact of local climate on past ice margin behavior is necessary to understand how modern ice sheet margins will respond to continued climate change. The researcher will pilot the generation of new, high-resolution temperature and hydroclimate records following the deglaciation of the northeastern United States by the Laurentide Ice Sheet following the Last Glacial Maximum. Temperature and hydroclimate will be reconstructed using branched glycerol dialkyl glycerol tetraethers (brGDGTs) and the hydrogen isotopic composition (δ2H) of precipitation from preserved leaf waxes, respectively, using sediment cores (in-hand and to-be-collected) from central New England. The researcher will accomplish this through extended visits to two laboratory facilities at the University of Colorado Boulder and in collaboration with their PIs and staff. These new records will be compared to the existing North American Varve Chronology which contains a detailed record of LIS retreat and ice margin fluctuations through the study area.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.