Collaborative Research: Assessing the Causal Influence of Atmospheric Opacity and Sea Ice on Arctic Warming in a Novel Circulation-controlled Framework

在过去的40年里，北极比地球上任何其他地区都要变暖。这种比全球变暖更快的北极变暖预计将继续下去，对人口、生态系统和基础设施产生持久影响。虽然导致北极变暖比全球变暖更快的基本机制是已知的，但控制北极变暖幅度的机制更难约束。该项目的重点是从1980年到2060年控制北极变暖的因素。通过指定相对较好约束的大气条件（风），项目团队将更好地理解难以观测约束的驱动因素（云和海冰厚度）的重要性。这项工作将导致我们对什么控制和不控制北极变暖的理解的变革性进展。该项目侧重于以下研究问题：海冰厚度和大气不透明度的因果影响是什么（即，最近和不久的将来北极变暖率？这个研究问题和相关的假设将在一个完善的NSF资助的地球系统模型（社区地球系统模型，CESM）中进行评估，该模型由观测指导，包括最近一年的实地活动和大量的原位观测（北极气候研究多学科漂移观测站，MOSAiC）。核心成果将是量化的因果影响的两个平均状态属性（大气不透明度，海冰厚度）对北极变暖率从1980年到2060年使用一种新的“风轻推”的方法，限制了大规模的大气环流。将围绕驾驶问题开发一个基于调查的2周初中课程：北极如何影响你所在地区的天气？该课程将由专家审查，并通过虚拟教师研讨会传播，使北美数百名教师能够将当前的北极研究带入课堂。该项目还将积极吸引早期职业科学家参与研究，包括一名博士。该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

Over the last 40 years, the Arctic has warmed more than any other region on the planet. This greater-than-global Arctic warming is projected to continue, with lasting impacts on human populations, ecosystems, and infrastructure. While the fundamental mechanisms that lead to greater-than-global Arctic warming are known, the mechanisms controlling the magnitude of Arctic warming are harder to constrain. This project is focused on what has and will control Arctic warming from 1980 to 2060. By specifying aspects of the atmospheric conditions that are relatively well constrained (the winds), the project team will better understand the importance of drivers that are harder to constrain observationally (clouds and sea ice thickness). This work will lead to transformational advances in our understanding of what does and does not control Arctic warming.This project is focused on the following research question: What is the causal influence of sea ice thickness and atmospheric opacity (i.e., clouds) on recent and near-future Arctic warming rates? This research question and associated hypotheses will be assessed in a well-established NSF-funded earth system model (Community Earth System Model, CESM) guided by observations including those from a recent year-long field campaign with substantial in situ observations (Multidisciplinary drifting Observatory for the Study of Arctic Climate, MOSAiC). The central outcome will be quantifying the causal influence of two mean state properties (atmospheric opacity, sea ice thickness) on Arctic warming rates from 1980 to 2060 using a novel ‘wind-nudging’ methodology that constrains the large-scale atmospheric circulation. An inquiry-based 2-week middle-high school curriculum will be developed centered around the driving question: How might weather in your area be impacted by the Arctic? The curriculum will be reviewed by experts and disseminated through virtual teacher workshops, enabling hundreds of teachers in North America to bring current Arctic research into their classrooms. The project will also actively engage early career scientists in the research including a Ph.D. student and two summer Research Experience for Undergraduates (REU) summer students.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.