Collaborative Research: Analysis of McCall Glacier Ice Core and Related Modern Process Studies

This is a collaborative project involving four institutions. The proposed research addresses two major questions related to climate in the eastern Alaskan Arctic: 1) How has climate, terrestrial ecology, and pollutant transport changed over the past 250 years in this region, based on ice core reconstructions from McCall Glacier? and 2) How well can we overcome the challenges of core proxy interpretations from ice cores taken from small polythermal valley glaciers through modern-process studies? To answer these questions the investigators conduct an inter-disciplinary analysis of ice core proxies, atmospheric dynamics, modern processes, and numerical ice flow modeling. A 152-meter long core has already been drilled through McCall Glacier and analyzed for 35 chemical proxies. The proposed work will focus on 1) interpretation of these proxies, 2) analysis of pollen in the core, 3) process studies to identify sources of pollen to McCall Glacier, 4) tying the weather and climate record of the past 50 years to the upper section of the core, 5) continuing 3D flow modeling of the glacier and local weather observations, 6) conducting modern process investigations of the effects of seasonal melt on the generation of the core proxy record. The project will support two graduate students.本项目为跨四家科研机构的协作研究课题。本项研究围绕阿拉斯加北极东部地区的气候相关核心议题展开，共包含两大研究方向：1) 基于麦肯尔冰川（McCall Glacier）的冰芯（ice core）重建数据，该区域过去250年间的气候、陆地生态学（terrestrial ecology）与污染物输送（pollutant transport）发生了何种演变？2) 借助现代过程研究（modern-process study），我们能否有效破解小型多热谷冰川（polythermal valley glacier）冰芯代用指标（ice core proxy）的解译难题，其解决效果可达何种程度？为解答上述问题，研究团队将开展冰芯代用指标、大气动力学（atmospheric dynamics）、现代过程研究与冰流数值模拟（numerical ice flow modeling）的跨学科分析。目前，研究团队已在麦肯尔冰川钻取总长152米的冰芯，并完成了35项化学代用指标的分析工作。本项目拟推进的研究内容将聚焦以下六个方面：1) 前述冰芯代用指标的解译；2) 冰芯内花粉的分析；3) 开展过程研究以明确麦肯尔冰川冰芯中花粉的来源；4) 将过去50年的气象与气候记录与冰芯上部层段进行关联匹配；5) 持续推进该冰川的三维冰流模拟与局地气象观测研究；6) 开展现代过程调查，解析季节性消融对冰芯代用指标记录形成的影响。本项目将资助两名研究生参与研究工作。