Collaborative Research: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation

合作研究：雪巨沙丘的特征及其对冰芯解释的潜在影响

• 批准号: 0225992
• 负责人: Mark Fahnestock
• 金额: $ 28.16万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-07-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0225992&HistoricalAwards=false
• 关键词: Collaborative; Research; Characteristics; Snow; Megadunes

This award supports a program of field surveys of an area within the large, well-developed megadune field southeast of Vostok station. The objectives are to determine the physical characteristics of the firn across the dunes, including typical climate indicators such as stable isotopes and major chemical species, and to install instruments to measure the time variation of near-surface wind and temperature with depth, to test and refine hypotheses for megadune formation. Field study will consist of surface snowpit and shallow core sampling, ground penetrating radar (GPR) profiling, GPS topographic and ice motion surveys, AWS installation, accumulation/ ablation measurements, subsurface temperature, and firn permeability studies. Field work in two successive seasons is proposed. Continent-wide remote sensing studies of the dunes will be continued, using the new group of instruments that are now, or will shortly be available (e.g., MODIS, MISR, GLAS, AMSR). The earlier study of topographic, passive microwave, and SAR characteristics will be extended, with the intent of determining the relationships of dune amplitude and wavelength to climate parameters, and further development of models of dune formation. Diffusion, ventilation, and vapor transport processes within the dune firn will be modeled as well. A robust program of outreach is planned and reporting to inform both the public and scientists of the fundamental in-situ and remote sensing characteristics of these uniquely Antarctic features will be an important part of the work. Because of their extreme nature, their broad extent, and their potential impact on the climate record, it is important to improve our current understanding of these. Megadunes are a manifestation of an extreme terrestrial climate and may provide insight on past terrestrial climate, or to processes active on other planets. Megadunes are likely to represent an end-member in firn diagenesis, and as such, may have much to teach us about the processes involved.

该奖项支持对沃斯托克站东南部开发良好的大型巨型地下水区域内的一个区域进行实地调查的计划。 其目的是确定沙丘上积雪的物理特征，包括稳定同位素和主要化学物质等典型气候指标，并安装仪器测量近地表风和温度随深度的时间变化，以检验和完善巨丘形成的假设。实地研究将包括表面雪坑和浅芯取样、探地雷达剖面、全球定位系统地形和冰运动调查、自动气象站安装、积累/消融测量、地下温度和积雪渗透性研究。 建议在连续两个季节进行实地工作。 将继续利用现有或不久将提供的一组新仪器（例如，MODIS、MISR、GLAS、AMSR）。将扩大早先对地形、被动微波和合成孔径雷达特征的研究，目的是确定沙丘幅度和波长与气候参数的关系，并进一步发展沙丘形成模型。扩散，通风，和蒸汽输送过程中的沙丘积雪也将被模拟。计划开展一项强有力的外联方案，向公众和科学家报告这些独特的南极地貌的基本原地和遥感特征将是这项工作的一个重要部分。由于它们的极端性质，它们的广泛范围以及它们对气候记录的潜在影响，提高我们目前对这些问题的理解非常重要。 巨沙丘是极端陆地气候的一种表现，可能提供对过去陆地气候的了解，或其他行星上活跃的过程。 巨沙丘很可能代表了雪层成岩作用中的一个端元，因此，可能对我们了解所涉及的过程有很多帮助。