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.

该奖项支持在Vostok站东南的大型、发育良好的巨型油田内进行实地调查的项目。目的是确定沙丘上沙丘的物理特征，包括典型的气候指标，如稳定同位素和主要化学物质，并安装仪器来测量近地表风和温度随深度的时间变化，以测试和完善巨型沙丘形成的假设。现场研究将包括地表雪坑和浅层岩心取样、探地雷达（GPR）剖面、GPS地形和冰运动测量、AWS安装、堆积/消融测量、地下温度和岩石渗透率研究。建议连续两个季节进行野外工作。将继续使用现在或不久将可获得的一组新仪器（例如MODIS、MISR、GLAS、AMSR）进行全大陆范围的沙丘遥感研究。早期的地形、被动微波和SAR特征研究将得到扩展，旨在确定沙丘振幅和波长与气候参数的关系，并进一步发展沙丘形成模式。沙丘内的扩散、通风和水汽输送过程也将被模拟。一项强有力的外联和报告计划将成为这项工作的重要组成部分，向公众和科学家通报这些独特的南极特征的基本原位和遥感特征。由于它们的极端性质、范围广泛，以及它们对气候记录的潜在影响，提高我们目前对它们的理解是很重要的。巨型沙丘是极端陆地气候的一种表现形式，可能为了解过去的陆地气候或其他行星上活跃的过程提供线索。Megadunes很可能代表了公司成岩作用的末端成员，因此，可能对所涉及的过程有很多启示。