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

该奖项支持对沃斯托克站东南部大型、发达的巨型沙丘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种等典型气候指标，并安装仪器来测量近地表风和温度随深度的时间变化，测试和完善大沙丘形成的假设。实地研究将包括地表雪坑和浅层岩心采样、探地雷达(GPR)剖面图、GPS地形和冰移测量、自动气象站安装、累积/烧蚀测量、地下温度和降雪渗透率研究。提出了连续两个季节的野外作业。将利用现在或即将推出的一组新仪器(例如MODIS、MISR、GLAS、AMSR)，继续进行全大陆范围的沙丘遥感研究。早期对地形、被动微波和合成孔径雷达特征的研究将得到扩展，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的模型。沙丘积雪内的扩散、通风和水汽输送过程也将被模拟。正在计划一项强有力的外联方案，向公众和科学家通报这些独特的南极地物的基本就地和遥感特征将是这项工作的重要组成部分。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，提高我们目前对它们的理解是重要的。大沙丘是极端陆地气候的表现，可以提供对过去陆地气候的洞察，或对其他行星上活跃的过程的洞察。大沙丘很可能代表着积雪成岩作用中的一个终端成员，因此，它可能会告诉我们很多关于相关过程的知识。

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.