Collaborative Research: Arctic Hydrological Regime Shift in a Warming Climate

北极目前变暖的速度比全球其他任何地区都快，最近气候和水文的变化对斯瓦尔巴特群岛产生了直接影响，在那里，山洪暴发和陡坡上冻土上的大规模移动增加，偶尔会导致灾难性的斜坡坍塌。这项研究将研究气候变暖如何在发生重大海冰损失的地区附近导致一种新的水文状况。新的水文状况是年降水量增加的结果，特别是在秋季和春季的过渡季节，降水量以雨而不是雪的形式出现的比例更高。根据这一合作项目，该小组将每年研究斯瓦尔巴群岛西部(挪威北极)湖泊中的层状沉积物，以确定最近水文变化的沉积信号，并利用这一信号重建与降雨有关的沉积事件的长期历史，以确定过去可能发生过类似情况的时间。该项目将包括一名博士后科学家、一名研究生、马萨诸塞大学和贝茨学院的本科生以及参与研究的教师。通过暑期方案对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在发生重大海冰损失的地区附近导致一种新的水文状况。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，以确定最近水文变化的沉积信号，并重建与降雨有关的沉积事件的长期历史，以确定过去可能发生过类似情况的时间。向湖泊输送的沉积物的类型和数量携带着有关湖泊流域的气象和水文条件的信息。研究人员将回收沉积物岩芯，以研究近年来沉积物堆积的结构和粒度分布，并与气象测量、圈闭中回收的沉积物以及负责沉积物输送和沉积的过程的测量进行比较。他们将使用微量分析技术进行高分辨率的粒度分析、变化量检测和测量。利用扫描电子显微镜图像分析方法，他们将重建降雨驱动的沉积事件。从沉积物捕集器获取的沉积物将使用激光粒度分析仪进行分析，以获得亚年度尺度的粒度剖面，以便与观测到的水文气候事件和变化的记录进行比较。这将为最近沉积变化的性质提供独特的视角，并洞察当代气候变化对该区域水文状况的影响。这一结果将对北极其他海冰迅速消退的地区产生影响。这一裁决反映了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。

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.