Histories of accumulation, thickness and WAIS Divide location from radar layers using a new inverse approach

该奖项支持开发一种新的建模方法，该方法将在西南极冰盖（WAIS）的罗斯-阿蒙森分水岭附近的未来冰芯附近提取有关过去积雪率的空间和时间信息。穿透冰雷达探测到的内层是等时线，即被随后的降雪掩埋并被冰流扭曲的原冰盖表面。广泛的破冰雷达数据可用于太平洋大陆架的内陆部分。地层可以追溯到距今17000年前。雷达数据将空间维度添加到冰芯的时间分辨累积记录中。积累速率传统上是由年轻的浅层深度得出的，并使用当地的一维冰流模型对应变进行校正。较老的、较深的地层受到较大水平距离的水流的影响更大。然而，正是这些更深的层包含了长期气候模式的信息。该项目将使用地球物理逆理论和包含冰面和层演化模块的2.5D流带冰流正演模型，通过吸收以前难以处理的多个更深、更变形的层来提取强大的瞬态积累模式。还将产生分区迁移、地热通量和地表演化的历史。该基金将通过华盛顿大学妇女中心支持一名女研究生的博士研究，她是对科学感兴趣的社会经济弱势女高中生的导师。它还将为本科生提供研究经验，并为新生科学研究研讨会做出贡献。

This award supports development of a new modeling approach that will extract information about past snow accumulation rate in both space and time in the vicinity of the future ice core near the Ross-Amundsen divide of the West Antarctic Ice Sheet (WAIS). Internal layers, detected by ice-penetrating radar, are isochrones, or former ice-sheet surfaces that have been buried by subsequent snowfall, and distorted by ice flow. Extensive ice-penetrating radar data are available over the inland portion of the WAIS. Layers have been dated back to 17,000 years before present. The radar data add the spatial dimension to the temporally resolved accumulation record from ice cores. Accumulation rates are traditionally derived from the depths of young, shallow layers, corrected for strain using a local 1-D ice-flow model. Older, deeper layers have been more affected by flow over large horizontal distances. However, it is these deeper layers that contain information on longer-term climate patterns. This project will use geophysical inverse theory and a 2.5D flow-band ice-flow forward model comprising ice-surface and layer-evolution modules, to extract robust transient accumulation patterns by assimilating multiple deeper, more-deformed layers that have previously been intractable. Histories of divide migration, geothermal flux, and surface evolution will also be produced. The grant will support the PhD research of a female graduate student who is a mentor to female socio-economically disadvantaged high-school students interested in science, through the University of Washington Women's Center. It will also provide a researchexperience for an undergraduate student, and contribute to a freshman seminar on Scientific Research.