Using Emergent Constraints to Reduce Uncertainty in Regional Climate Change

越来越需要在与决策者和利害关系方相关的空间尺度上对未来气候变化进行强有力的预测。然而，我们对这些区域尺度上与气候变化相关的许多风险的理解往往受到气候模型预测的不确定性的限制（即，不同的气候模式对未来气候给出不同的答案）。当涉及到水循环的变化时，这些模型的答案范围特别大，这具有很大的社会意义。在这里，研究人员将依靠一种领先的气候模型评估技术，该技术利用对当前气候的观测来缩小气候模型对未来地球仪各地区降水、干旱和径流变化的回答范围。此外，这项工作将扩大我们对模型分歧的关键来源的了解，为气候模拟中心的未来发展提供信息。研究人员还将首次将这种方法应用于覆盖美国西部的高分辨率气候模型模拟。这些模拟比全球气候模型更好地代表了该地区复杂的地形，从而可以更可靠地预测山区积雪，这在该地区的水循环中起着关键作用。这项研究将寻求减少积雪对未来变暖的反应的不确定性，并将这些知识应用于更好地了解与淡水供应和干旱相关的风险。通过关注与水循环相关的气候指标，这对美国西部等水资源紧张地区具有巨大影响，这项研究将对科学界以外的各种群体具有价值。在现有利益相关者合作的基础上，研究人员将与美国西部的几个团体合作，以帮助塑造研究成果，使其具有广泛的社会相关性。该项目将为一名研究生和一名博士后学者提供培训机会。此外，研究人员将在美国地球物理联盟秋季会议上召开会议，以促进有关相关研究的讨论。最后，来自美国西部的水资源管理、荒地和火灾管理以及公共卫生界的代表将参加一个虚拟研讨会，以传播该研究成果，作为该项目的顶点。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。

There is a growing need for robust projections of future climate change at spatial scales relevant to policymakers and stakeholders. However, our understanding of the many risks associated with climate change at these regional scales is often limited by uncertainty in climate model projections (i.e., different climate models give different answers about future climate). The range of answers across the models is particularly large when it comes to changes in the water cycle, which are of great societal relevance. Here, the investigators will rely on a leading climate model evaluation technique that uses observations of the current climate to narrow the range of climate model answers regarding future changes to precipitation, drought, and streamflow across regions of the globe. Moreover, this work will expand our knowledge of the key sources of model disagreement to inform areas of future development for climate modeling centers. The investigators will also, for the first time, apply this methodology to a collection of high-resolution climate model simulations covering the Western United States. These simulations better represent the complex topography of the region than global climate models, and thus allow for more reliable depictions of mountain snowpack, which plays a pivotal role in the region’s water cycle. This research will seek to reduce uncertainty in the snowpack’s response to future warming and apply this knowledge to better understand risks associated with freshwater availability and drought.By focusing on climate metrics relating to the water cycle, which have enormous implications in water-stressed regions like the Western United States, this research will be valuable to a variety of constituencies outside the scientific community. Building off existing stakeholder collaborations, the investigators will engage with several groups across the Western United States to help shape the research so that the results have broad societal relevance. This project will provide training opportunities for a graduate student and a postdoctoral scholar. Additionally, the investigators will convene sessions at the American Geophysical Union’s Fall Meeting to catalyze discussions regarding relevant research. Lastly, a virtual workshop involving representatives from water resource management, wild land and fire management, and public health communities from across the Western United States will be held to disseminate the research as a capstone to the project.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.