Doctoral Dissertation Research: Climate and Topographic Controls on Little Ice Age Glacial Advances

本博士论文项目研究了小冰期（LIA，大约公元1300年至1850年）气候和地形对冰川推进的控制。冰川为世界各地的干旱和半干旱地区提供了重要的淡水供应，因此了解冰川的动态具有重要的社会意义。冰川的前进和后退受到气候变化的强烈影响，但也受到当地地形和冰川因素的影响。这些因素可以增强或减弱温度和湿度变化的影响。该项目将限制LIA冰川推进留下的地貌的形成年龄，以测试LIA冰川推进在山区是否不同步。然后，利用谷歌地球图像绘制的LIA和现代冰川范围的详细地图，评估LIA冰川推进幅度与当地地形和冰川因素之间的关系。了解小冰期冰川推进的时空格局将为了解不同大气系统的主导地位变化及其与当地地形和冰川因素的相互作用提供重要见解。这些知识对于气候模式预测未来气候情景至关重要。特别是，从中亚高原选定的地点进行的详细研究将提供对西风带和西伯利亚高压之间的关系的理解，可能还有亚洲季风，在复杂的山区景观中驱动冰川前进和后退。该项目将填补关于小冰期冰川推进时间和范围的知识空白，并提供约束良好的古气候信息，以帮助更好地了解未来的气候和环境变化。基于高分辨率谷歌地球图像绘制的冰川地图将提供最新的冰川清单，以记录冰川变化的状况。除了支持本博士论文研究外，本项目还将为一名本科生提供地质测年和古气候重建方面的培训。本项目的研究成果将通过会议报告、期刊出版物和科学推广等方式传播给各种受众，并将研究内容纳入当地K-12学校和田纳西大学孔子学院的外语（中文）课程。作为博士论文研究进步奖，该项目将提供支持，使有前途的学生建立一个独立的研究生涯。

This doctoral dissertation project investigates the climate and topographic controls on glacial advances during a period known as the Little Ice Age (LIA, approximately AD 1300 to 1850). Glaciers provide a critical freshwater supply in arid and semi-arid areas around the world, so understanding the dynamics of glaciers is of societal importance. Glacial advances and retreats are strongly affected by climate change, but are also influenced by local topographic and glaciological factors. These factors then can either reinforce or dampen the effects of changes in temperature and moisture. This project will constrain the formation ages of the landforms left behind by the LIA glacial advances to test whether the LIA glacial advances are asynchronous across a mountain region. Then, detailed mapping of the LIA and modern glacier extents from Google Earth imagery will be used to evaluate the relationship between the magnitude of the LIA glacial advances and local topographic and glaciological factors. Understanding the spatial and temporal pattern of the LIA glacial advances will provide significant insights into the shifting dominance of different atmospheric systems and their interplay with local topographic and glaciological factors. This knowledge is of critical importance for climate models to predict future climate scenarios. In particular, the detailed study from the sites selected in the Central Asian highlands will provide an understanding of relationships between the westerlies and the Siberian High, and possibly the Asian monsoon, in driving glacial advances and retreats over complex mountainous landscapes.This project will fill a gap in knowledge of the timing and extent of the LIA glacial advances and provide well-constrained, paleo-climate information to help better understand future climate and environmental changes. The glacial maps delineated based on high-resolution Google Earth imagery will provide an updated glacier inventory to document the status of glacier changes. In addition to the support for this doctoral dissertation research, this project will provide training for an undergraduate student in geologic dating and paleo-climate reconstruction. Research results of this project will be disseminated to a variety of audiences through conference presentations, journal publications, and scientific outreach by integrating the research content into foreign language (Chinese) classes in local K-12 schools and the Confucius Institute at the University of Tennessee. As a Doctoral Dissertation Research Improvement award, this project will provide support to enable a promising student to establish an independent research career.