Collaborative Research: Arctic Hydrological Regime Shift in a Warming Climate

北极目前的变暖速度比地球仪上任何其他地区都快，最近的气候和水文变化对斯瓦尔巴特群岛产生了直接影响，那里的山洪暴发和陡坡冻土上的物质运动加剧，有时会导致灾难性的边坡崩塌。这项研究将探讨气候变暖如何导致海冰大量减少地区的邻近地区出现新的水文状况。新的水文状况是年降水量增加的结果，其中更大比例是雨而不是雪，特别是在秋季和春季的过渡季节。在这一合作项目下，该团队将每年研究斯瓦尔巴群岛西部湖泊（挪威北极地区）的层状沉积物，以确定近期水文变化的沉积信号，并利用这一信号重建与冰川有关的沉积事件的长期历史，以确定过去类似条件可能存在的时间。该项目将涉及一名博士后科学家，一名研究生，以及马萨诸塞州大学和贝茨学院的本科生，以及参与研究的教师。通过暑期项目对STEM教师进行培训，使他们能够将北极地球科学活动纳入课堂课程。该项目将研究气候变暖如何导致海冰大量减少地区的邻近地区出现新的水文状况。研究人员将每年研究斯瓦尔巴群岛西部湖泊中的层状沉积物，以确定近期水文变化的沉积信号，并重建与冰川相关的沉积事件的长期历史，以确定过去类似的条件可能在何时普遍存在。输往湖泊的沉积物的类型和数量携带着湖泊流域气象和水文条件的信息。调查人员将采集沉积物岩心，研究近年来沉积物积累的结构和粒度分布，与气象测量结果、捕获器中采集的沉积物以及沉积物迁移和沉积过程的测量结果进行比较。他们将采用微分析技术进行高分辨率粒度分析、纹层探测和测量。利用扫描电子显微镜图像分析方法，他们将重建火山驱动的沉积事件。将使用激光粒度分析仪分析从沉积物收集器获得的沉积物，以获得次年度尺度的粒度分布图，与观测到的水文气候事件和变化记录进行比较。这将提供一个独特的视角，最近的沉积变化的性质，并提供洞察当代气候变化对该地区的水文制度的影响。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The Arctic is currently warming faster than any other region of the globe, and recent changes in climate and hydrology have had direct impacts in Svalbard, where flash flooding and enhanced mass movement over frozen ground on steep slopes has occasionally led to catastrophic slope failure. This study will examine how warming is leading to a new hydrological regime in regions adjacent to the areas where major sea-ice losses have occurred. The new hydrological regime is result of an increase in annual precipitation, a higher proportion of which is in the form of rain rather than snow, especially in the transition seasons of fall and spring. Under this collaborative project, the team will study annually laminated sediments in lakes of western Svalbard (Norwegian Arctic) to identify the sedimentary signal of recent changes in hydrology and use this to reconstruct the long-term history of rainfall-related sedimentary events to determine when similar conditions may have prevailed in the past. This project will involve a postdoctoral scientist, a graduate student, and undergraduate students at University of Massachusetts and Bates College, as well as teacher in the research. There is training of STEM teachers through a summer program enabling them to incorporate Arctic earth science activities into their classroom curricula. This project will examine how warming is leading to a new hydrological regime in regions adjacent to the areas where major sea-ice losses have occurred. The investigators will study annually laminated sediments in lakes of western Svalbard to identify the sedimentary signal of recent changes in hydrology and reconstruct the long-term history of rainfall-related sedimentary events to determine when similar conditions may have prevailed in the past. The type and amount of sediment transported to lakes carries with it information about meteorological and hydrological conditions in the lake watershed. The investigators will recover sediment cores to study the structure and grain size profiles of recent years of sediment accumulation, to compare with meteorological measurements, sediment recovered in traps, and measurements of processes responsible for sediment transport and deposition. They will employ microanalytcal techniques for high-resolution grain size analysis, varve detection and measurement. Using scanning electron microscope image analysis methods, they will reconstruct rainfall-driven sedimentary events. Sediments acquired from sediment traps will be analyzed using a laser particle size analyzer to obtain sub-annual scale grain size profiles to compare with observed hydroclimatic events and the varved records. This will provide a unique perspective on the nature of recent sedimentary changes and provide insight into the effects of contemporary changes in climate on the hydrological regime of this region. The results will have implications for other parts of the Arctic where sea-ice is rapidly receding.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.