ArcticDEM Production

该项目将利用Blue Waters持续的千万亿级计算能力，构建首个高分辨率(2m)、高质量(5m不确定性)和开放分布的数字高程模型(DEM)集，涵盖北纬60度以上的所有北极陆块，包括格陵兰、阿拉斯加和堪察加的所有地区。这样的DEM集对于测量和理解气候变化和人类使用导致的北极景观的快速、持续变化，以及北极社区的缓解和适应规划都是必要的。获取和维护图像的资源、后处理结果的工具、软件开发时间和分发数字高程模型的方法都已得到保障。在蓝色水域上使用的计算时间需要提供整个北极的数字高程模型覆盖。DEM将免费提供给科学界和广大公众，并将履行美国在担任北极理事会主席期间对其北极伙伴的承诺。一个全面、小比例尺的北极DEM的产生将改变北极研究界和北极社会。DEM将提供有时间戳的冰面范围和冰面高度观测，并可在环境作用力变化的背景下进行检查。DEM的细节将使冰上水文学的演变能够被研究到单个湖泊和溪流的水平。正如最近发表在《自然》杂志上的那样，冰川下水文变化引起的地表下沉也将可供研究(I.M.Howat等人。2015年；帕尔默、麦克米兰和莫里赫姆2015年；威利斯等人。2015年)。此外，北极DEM的范围与北半球的永久冻土范围几乎完全匹配，因此DEM集将使研究主要的热岩溶变化和冰缘丘陵坡度演化成为可能。研究多年冻土地区的静态、动态、宏观和微观表面地形是美国国家科学院的一项主要建议，目的是进一步了解多年冻土地区及其滞留的碳是如何应对气候变暖的(国家研究理事会2014)。此外，DEM将能够详细检查海岸的演变，突出海岸线以恒定的速度侵蚀，并对极端事件做出反应，如海岸线冰挤或IVU。改变湖泊大小和位置(可能还有深度)以及河流和三角洲形态的分布在数据集中将是显而易见的，这将对湿地、生态系统、野生动物管理和可持续性产生影响。冰/火山相互作用、过程地貌、构造地貌、板块边界相互作用、断层表达、断层演化、冰川地貌以及来自弯曲湖岸线的固体地球动力学都将从新的数据中提供。此外，大气科学研究，如研究小气候、山谷尺度大气动力学和烟风，将使用新的细尺度地形来进行缩小尺度或微区域大气模型。社区还可能使用DEM来预测和处理永久冻土影响、海平面上升、泛滥平原划界和灾害管理。

The project will use the sustained, petascale computing capabilities of Blue Waters to construct the first high-resolution (2m), high-quality (5m uncertainty), and openly distributed digital elevation model (DEM) set of all Arctic land masses above 60 degree N, including all of Greenland, Alaska, and Kamchatka. Such a DEM set is needed for measuring and understanding rapid, ongoing changes to the Arctic landscape resulting from climate change and human use, as well as mitigation and adaptation planning for Arctic communities. Resources for obtaining and maintaining the imagery, tools for post-processing the results, software development time, and methods for distributing the DEM have been secured. The compute time used on Blue Waters is needed to provide DEM coverage of the entire Arctic. DEMs will be provided at no cost to the science community and public at large, and will fulfill the United States' commitment to its Arctic partners as part of its tenure as chair of the Arctic Council. The production of a comprehensive, fine-scale Arctic DEM will transform the Arctic research community and Arctic society. The DEMs will provide time-stamped observations of ice extent and ice surface height and can be examined within the context of changing environmental forcings. The detail of the DEMs will allow the evolution of supraglacial hydrology to be examined down to the level of individual lakes and streams. As published recently in Nature, surface subsidence caused by subglacial hydrological changes will also be available for study (I. M. Howat et al. 2015; Palmer, McMillan, and Morlighem 2015; Willis et al. 2015). Furthermore, the extent of Arctic DEM almost exactly matches the extent of permafrost in the northern hemisphere, so the DEM set will make it possible to examine major thermokarst changes and periglacial hill slope evolution. Examination of the static, dynamic, macro- and micro-surface topography of permafrost regions is a major recommendation of the U.S. National Academy of Sciences to enablefurther understanding of how permafrost regions and their trapped carbon are responding to a warming climate (National Research Council 2014). Additionally, the DEMs will enable detailed examination of coastal evolution, highlighting shoreline erosion at constant rates and in response to extreme events such as a shoreline ice-shove, or ivu. Changing distribution of lake size and location (and possibly depth) and river and delta morphology will be apparent in the data set, with ramifications for wetlands, ecosystems, and wildlife management and sustainability. Ice/volcano interactions, process geomorphology, tectonic geomorphology, plate boundary interactions, fault expressions, fault evolution, glacial geomorphology, and solid earth geodynamics derived from bending lake shorelines will all be provided from the new data. Moreover, atmospheric science pursuits such as the study of microclimates, valley-scale atmospheric dynamics and foehn winds will use the new fine-scale topographies for downscaled or micro-region atmospheric models. Communities are also likely to use the DEMs to anticipate and address permafrost impacts, rising sea level, floodplain delimitation and disaster management.