Diagnosing the Climatic Causes and Consequences of Snow Depth Variability

诊断雪深变化的气候原因和后果

• 批准号: 0808975
• 负责人: Upmanu Lall
• 金额: $ 30.91万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-10-01 至 2011-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0808975&HistoricalAwards=false
• 关键词: Diagnosing; Climatic; Causes; Consequences; Snow

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.

拟议工作的目标是提供一个更好的了解积雪深度？气候的关系和物理机制。大量的科学文献描述了积雪范围异常与气候之间的联系，但积雪范围本身并不能说明全部问题。积雪深度的变化不一定与积雪范围的变化相一致，但可能在一系列空间和时间尺度上对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文献雪深？气候联系。雪深-气候关系可能非常复杂，涉及不同空间域和尺度的不同动力学和热力学过程。这种整体关系的某些方面比其他方面更容易理解，而其他方面可能会受益于使用更新的数据和/或建模资源进行的更新分析。因此，建议的工作将具体针对两个方面的整体积雪深度？我们目前的理解还不完整的气候关系。两个假设进行了研究，第一个涉及北美雪深变化的远程气候原因，第二个涉及雪深变化的局部气候后果。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，特别是在北美的北方地区，那里的雪深信息历史上一直缺乏，但预计会有很大的变化。因此，这个经常被忽视的参数可以在比以前更广泛的领域进行经验评估。此外，还将利用一维积雪模式和区域气候模式进行雪深扰动试验，以综合评估与雪深异常相关的热力学和近地面动力学过程，诊断雪深变化的具体气候原因和后果，而不是探索性的和无重点的研究整体关系，在水文和气候科学界取得成功和产生影响的前景最好。认识到雪深是气候变化的一个重要因素，将促进气候模型中仍然相对粗糙的雪参数化的持续改进，并促进雪深遥感技术的持续改进。明确雪深与雪广的联系概念，会使人们对雪有更全面的认识吗？气候关系，并提供新的信息，以帮助确定其他地区/季节，可能持有一些预测能力的气候。这反过来又将对水资源管理、减灾和人为气候变化产生深远的社会效益，将对拟议的研究进行管理，以最大限度地扩大其对教育的广泛影响。尽管其重点范围和相对温和的预算，该项目将支持三个学生在他们的教育生涯的显着不同的阶段。一个PI的博士候选人？的机构将完成她的论文，并确保顺利和有效地过渡到一个新的博士生为这个项目的持续时间。此外，一个高中生在纽约市？美国著名的布朗克斯科学高中将得到赞助，该项目的研究将进入英特尔科学人才搜索比赛（http：//www.scierv.org/Sts/）。这种早期接触研究可以激励学生追求科学和工程事业，并促进下一代研究人员的发展。