Diagnosing the Climatic Causes and Consequences of Snow Depth Variability

这项工作的目标是提供对雪深的更好理解。气候关系和所涉及的物理机制。大量的科学文献描述了雪量异常与气候之间的联系，但雪量本身并不能说明全部情况。积雪深度的变化不一定与积雪范围的变化一致，但可能对一系列时空尺度上的气候产生明显和相当大的影响。PI最近完成的研究清楚地区分了雪深的气候意义，并补充了一些有限的现有雪深文献。气候的联系。这是本建议确定负责机制的动机。雪深与气候的关系可能非常复杂，在不同的空间域和尺度上涉及不同的动力和热力学过程。这种整体关系的某些方面比其他方面更容易理解，而其他方面可能受益于使用最新数据和/或建模资源的更新分析。因此，建议的工作将具体针对两个方面的整体雪深？气候关系，我们目前的理解是不完整的。研究了两个假设，第一个涉及北美雪深变率的遥远气候原因，第二个涉及雪深变率的局部气候后果。该建议的一个关键资源是新发布的覆盖整个北美的长期网格化日雪深数据集（Dyer and Mote 2006）。它的可用性为研究雪深及其与气候的相互作用提供了令人兴奋的新机会，特别是在北美北部地区，那里的雪深信息历来缺乏，但预计会有很大的变化。因此，这个经常被忽略的参数可以在比以前更广泛的领域进行经验评估。在此基础上，利用一维积雪模式和区域气候模式进行雪深扰动试验，综合评价与异常雪深相关的热力和近地表动力过程。诊断雪深变率的具体气候原因和后果，而不是对总体关系进行探索性和无重点的研究，在水文和气候科学界具有最大的成功前景和影响。认识到雪深是气候变化的一个重要因素，将促进气候模式和雪深遥感技术中仍然相对粗糙的雪参数化的持续改进。不同雪深和雪度联系的概念将导致对雪的更全面的理解。气候关系，并提供新的信息，以帮助确定可能具有气候预测能力的其他地区/季节。这反过来又将对水资源管理、减轻灾害和人为气候变化产生深远的社会效益。拟议的研究将设法最大限度地扩大其对教育的广泛影响。尽管该项目范围集中，预算相对有限，但它将支持三名处于教育生涯截然不同阶段的学生。PI现有的博士候选人？S机构将完成她的论文，并确保在该项目期间顺利高效地过渡到新的博士生。此外，纽约市的一名高中生？美国著名的布朗克斯科学高中（Bronx High School of Science）将得到赞助，该项目的研究将参加英特尔科学人才选拔大赛（http://www.sciserv.org/Sts/）。这种早期接触研究可以激励学生追求科学和工程方面的职业，并促进下一代研究人员的发展。

The goal of the proposed work is to provide an improved understanding of snow depth ? climate relationships and the physical mechanisms involved. An extensive body of scientific literature describes the linkages between snow extent anomalies and climate, but snow extent alone does not tell the whole story. Variations in snow depth, which do not necessarily coincide with variations in snow extent, may have a distinct and considerable impact on climate over a range of spatial and temporal scales. Recently completed research by the PI clearly distinguishes the climatic significance of snow depth, and complements the somewhat limited existing literature on snow depth ? climate linkages. This serves as motivation for this proposal to identify the responsible mechanisms.The snow depth - climate relationship is likely to be very complicated, and involve different dynamic and thermodynamic processes across varying spatial domains and scales. Some facets of this overall relationship are better understood than others, while still other facets may benefit from updated analyses using more recent data and/or modeling resources. Therefore the proposed work will specifically target two aspects of the overall snow depth ? climate relationship where our current state of understanding is incomplete. Two hypotheses are investigated, the first involving a remote climatic cause for snow depth variability over North America, and the second involving a local climatic consequence of snow depth variability.A key resource for this proposal is a newly released, long-term, gridded, daily snow depth dataset covering all of North America (Dyer and Mote 2006). Its availability offers exciting new opportunities to study snow depth and its interactions with climate, especially in northern regions of North America where snow depth information has historically been lacking but is expected to vary considerably. Hence this frequently neglected parameter can be empirically evaluated over a broader domain than previously was possible. Furthermore, snow depth perturbation experiments will be performed using both a one-dimensional snowpack model and a regional climate model, to comprehensively evaluate the thermodynamic and near-surface dynamic processes associated with anomalous snow depth.Diagnosing specific climatic causes and consequences of snow depth variability, rather than an exploratory and unfocused study of the overall relationships, hold the strongest prospects for success and impact within the hydrologic and climate science communities. Recognition of snow depth as an important contributor to climate variations will promote continued improvements in the still relatively crude snow parameterizations in climate models, and also in snow depth remote sensing techniques. The concept of distinct snow depth and snow extent linkages will lead to a more comprehensive understanding of snow ? climate relationships, and provide new information to help identify additional regions/seasons which may hold some predictive capability for climate. This in turn would have far-reaching societal benefits for water resource management, hazard mitigation and anthropogenic climate change.The proposed research will be managed to maximize its broader impacts on education. Despite its focused scope and relatively modest budget, the project will support three students at dramatically different stages of their educational career. An existing doctoral candidate at the PI?s institution will complete her dissertation, and ensure a smooth and efficient transition to a new doctoral student for the duration of this project. Furthermore, one high school student at New York City?s prestigious Bronx High School of Science will be sponsored, whose research on this project will be entered in the Intel Science Talent Search competition (http://www.sciserv.org/Sts/). Such early exposure to research can inspire students to pursue careers in science and engineering, and foster the development of the next generation of researchers.