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

该合同支持一个项目，通过处理现有的2000年美国ITASE穿越的近地表雷达数据，并通过收集和验证新的超/超高频（UHF）近表层（深度约15米）的雷达图像，扩大监测最近从点源冰芯到雷达线的年积累模式的能力，扩大对南极西部冰盖年积累模式的了解。浅层（15米）冰芯将与超高频雷达图像一起收集，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/或次年密度变化相对应。该项目还将通过将空间雷达获得的年积累时间序列与30多年前覆盖南极洲大部分地区的无源微波时间序列进行比较，改进星载仪器的积累监测。该项目的知识价值在于，绘制南极冰盖积累速率的时空变化图对于了解冰盖对气候强迫的响应至关重要。由于预测的变暖，预计南极的降水率在未来一个世纪将增加20%。积累是确定冰盖质量平衡和海平面上升的关键组成部分，然而我们测量过去50年（卫星时代）年积累变化的能力主要局限于点源冰芯。开发雷达和冰芯衍生的年度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，还将建立积累趋势。该项目的更广泛的影响是，它将通过验证使用超高频雷达监测年度层（由相应的浅层冰芯的视觉、化学和同位素分析确定），从而促进气候学、冰川学和遥感界的发现和理解，并将从现有雷达数据和拟议雷达数据中提供过去~ 50年在WAIS分水岭上的年度至近年度累积测量数据集。通过确定被动微波信号的时间变化是否与积累的时间变化相关，将有助于评估被动微波遥感在监测未来几十年冰盖积累率方面的效用。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，为K-12教师提供监测美国积雪和温度的培训，将极地研究与学生联系起来，从而增加代表性不足群体的代表性。年代的后院。该项目将对本科生和研究生进行极地研究方面的培训，并鼓励年轻的研究人员投身科学事业。特别是，两名REU学生将参与原创性研究项目，作为这个更大项目的一部分，从假设的发展到结果的展示和出版。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.