Collaborative Research: Annual satellite era accumulation patterns over WAIS Divide: A study using shallow ice cores, near-surface radars and satellites

该奖项支持一个项目，通过处理2000年在美国ITASE导线上获取的现有近地表雷达数据，并通过收集和验证新的近表层(至15米深处)的超高频(UHF)雷达图像，扩大监测从点源冰芯到雷达线的近期年积累模式的能力，从而扩大对西南极冰盖上年积累模式的了解。将结合超高频雷达图像收集浅层(15米)冰芯，以确认雷达回波与根据冰芯稳定同位素确定的近地表雪的年层和/或亚年度密度变化相对应。该项目还将通过将空间雷达得出的年积累时间序列与30多年前复盖南极洲大部分地区的被动微波时间序列进行比较，来改进对空间仪器的积累监测。该项目的学术价值在于，绘制南极冰盖上积累率的时空变化图，对于了解冰盖对气候强迫的反应至关重要。预计在未来一个世纪，南极的沉降率将比预测的变暖增加20%。积累是确定冰盖物质平衡的关键组成部分，因此海平面上升，然而我们测量过去50年(卫星时代)的年度积累变异性的能力主要限于点源冰芯。开发雷达和冰芯得出的年积累数据集将为空间遥感算法、气候模型提供验证数据，此外还将确定积累趋势。该项目的更广泛影响是，它将通过核查使用超高频雷达监测通过目测、化学和同位素分析从相应浅冰芯确定的年层，促进气候学、冰川学和遥感领域内的发现和了解，并将提供过去约50年WAIS的年度至近年度累积测量数据集，这与现有雷达数据和拟议雷达数据有所不同。通过确定被动微波信号的时间变化是否与积累量的时间变化相关，将有助于评估被动微波遥感在监测未来几十年冰盖上的积累率方面的作用。该项目将促进教学、培训和学习，并通过参与NASA冬季历史项目和Thermochron任务，通过为K-12教师提供监测美国这里的积雪和温度的培训，将极地研究与学生S的后院联系起来，从而促进教学、培训和学习，并增加代表性不足群体的代表性。该项目将对本科生和研究生进行极地研究方面的培训，并将鼓励年轻的研究人员投身于科学事业。特别是，两名REU学生将参与作为这一更大项目的一部分的原始研究项目，从提出假设到展示和发表结果。一位新的年轻女科学家的支持将有助于增加极地研究中的性别多样性。

This award supports a project to broaden the knowledge of annual accumulation patterns over the West Antarctic Ice Sheet by processing existing near-surface radar data taken on the US ITASE traverse in 2000 and by gathering and validating new ultra/super-high-frequency (UHF) radar images of near surface layers (to depths of ~15 m), expanding abilities to monitor recent annual accumulation patterns from point source ice cores to radar lines. Shallow (15 m) ice cores will be collected in conjunction with UHF radar images to confirm that radar echoed returns correspond with annual layers, and/or sub-annual density changes in the near-surface snow, as determined from ice core stable isotopes. This project will additionally improve accumulation monitoring from space-borne instruments by comparing the spatial-radar-derived-annual accumulation time series to the passive microwave time series dating back over 3 decades and covering most of Antarctica. The intellectual merit of this project is that mapping the spatial and temporal variations in accumulation rates over the Antarctic ice sheet is essential for understanding ice sheet responses to climate forcing. Antarctic precipitation rate is projected to increase up to 20% in the coming century from the predicted warming. Accumulation is a key component for determining ice sheet mass balance and, hence, sea level rise, yet our ability to measure annual accumulation variability over the past 5 decades (satellite era) is mostly limited to point-source ice cores. Developing a radar and ice core derived annual accumulation dataset will provide validation data for space-born remote sensing algorithms, climate models and, additionally, establish accumulation trends. The broader impacts of the project are that it will advance discovery and understanding within the climatology, glaciology and remote sensing communities by verifying the use of UHF radars to monitor annual layers as determined by visual, chemical and isotopic analysis from corresponding shallow ice cores and will provide a dataset of annual to near-annual accumulation measurements over the past ~5 decades across WAIS divide from existing radar data and proposed radar data. By determining if temporal changes in the passive microwave signal are correlated with temporal changes in accumulation will help assess the utility of passive microwave remote sensing to monitor accumulation rates over ice sheets for future decades. The project will promote teaching, training and learning, and increase representation of underrepresented groups by becoming involved in the NASA History of Winter project and Thermochron Mission and by providing K-12 teachers with training to monitor snow accumulation and temperature here in the US, linking polar research to the student?s backyard. The project will train both undergraduate and graduate students in polar research and will encouraging young investigators to become involved in careers in science. In particular, two REU students will participate in original research projects as part of this larger project, from development of a hypothesis to presentation and publication of the results. The support of a new, young woman scientist will help to increase gender diversity in polar research.