Change in the ice speed and mass balance of the Antarctic Ice Sheet, from Earth Observation satellite data

卫星对地观测彻底改变了我们对遥远和难以接近的极地地区的认识。如果没有这一关键资源，我们对哪些区域正在发生变化、事件发生的时间和速度以及推动变化的物理机制的了解将远远不完整。在南极洲，卫星数据对于揭示整个大陆冰流的空间格局、揭示海洋西南极冰盖的动态不平衡和相关的巨大海平面贡献、绘制海冰范围的季节性消长以及测量臭氧层空洞的大小和恢复至关重要。在过去的30年里，南极的个别冰流，如松岛冰川，自20世纪90年代初的S以来，冰流的速度增加了42%以上，现在已知是动态不平衡的。然而，尽管许多地区的冰速有明显的长期趋势，但观测到的速度并不是随着时间的推移而恒定的，而且也观察到了多年没有显著变化。有必要进行目前的冰速测量，以提供一种独立的手段，测量这片辽阔冰盖变化最快的地区的冰质量损失。该项目为研究气候变化的影响和影响的国际努力提供了一个令人兴奋的机会，为研究气候变化的影响和影响提供了一个令人兴奋的机会。这名博士生将获得详细的技术知识，了解如何使用多种处理技术，如干涉测量(InSAR)和特征跟踪，处理来自大量地球观测卫星，包括ERS-1/2，TerraSAR-X，Sentinel-1的合成孔径雷达(SAR)数据，以测量冰速。冰速的测量将结合冰床和冰面地形来计算南极冰盖上个别冰川的冰通量，然后计算物质平衡。冰速测量将被分析以检测速度随时间的变化，这将与补充观测相结合，例如冰解锋的位置和冰层变薄，以促进我们对驱动变化的物理机制的理解。这些结果将被用来改进和扩大冰盖对当今海平面上升的贡献，这是一个具有广泛社会意义的话题，并将使我们能够更好地预测未来冰盖将如何变化。在攻读博士学位的过程中，学生将撰写至少三篇有关这些重要科学主题的期刊论文，并有可能开展极地运动。这名博士生将在利兹大学极地观测和建模中心工作，因此将有宝贵的机会与欧洲空间局(欧空局)合作和参加会议，并与广泛的国际科学合作者接触。CPOM的学生身份提供了一个极好的机会，可以与英国各地大学的陆冰和海冰观测和建模专家组成的大型团队积极合作。该项目在以下方面提供高水平的培训：(1)卫星遥感；(2)极地实地工作；(3)冰川学；(3)数据分析和可视化；(4)卫星系统的校准和验证；以及(5)科学写作。成功的申请者将有机会获得广泛的地球观测和冰川学方面的专业培训，此外还可以参加利兹大学关于一系列主题的广泛研讨会，包括科学规划到学位管理。申请者将拥有良好的物理、数学、地球科学、气候科学、地球观测或相关专业的学士学位(第一或更高)或硕士学位。计算机编程方面的专业知识虽然不是必需的，但将是一笔宝贵的财富。

Satellite Earth Observation has revolutionized our understanding of the remote and inaccessible Polar Regions. Without this critical resource we would have a far less complete understanding of which regions are changing, the timing and pace at which events occur, and what physical mechanisms are responsible for driving change. In Antarctica, satellite data has been vital for revealing the continent-wide spatial pattern of ice flow; for uncovering dynamic imbalance and the associated large sea level contribution of the marine-based West Antarctic Ice Sheet; for mapping the seasonal growth and decay of sea ice extent; and for measuring the size and recovery of the Ozone hole. During the last 30-years, individual ice streams in Antarctica such as Pine Island Glacier, have increased in speed by over 42% since the early 1990's, and are now known to be dynamically imbalanced. However, despite a clear long-term trend for increasing ice velocity in many regions, the observed speed up has not been constant through time, and multiple years with no significant change have also been observed. It is necessary to make present day measurements of ice velocity to provide an independent means of measuring ice mass loss from the most rapidly changing regions of this vast ice sheet.This project offers an exciting opportunity to work at the interface of climate and space science, making an important contribution to international efforts to study the effects and impact of climate change. This PhD student will gain a detailed technical understanding of how to process Synthetic Aperture Radar (SAR) data from a large number of Earth Observation satellites, including ERS-1/2, TerraSAR-X, Sentinel-1, using multiple processing techniques, such as interferometry (InSAR) & feature tracking, to make measurements of ice speed. The measurements of ice speed will be used in combination with bed and ice surface topography to compute the ice flux, and then mass balance, of individual glaciers on the Antarctic Ice Sheet. The ice speed measurements will be analysed to detect change in speed over time, and this will be combined with complimentary observations, such as the calving front location and ice thinning, to advance our understanding of the physical mechanisms driving change. These results will be used to improve and extend the ice sheet contribution to present-day sea-level rise, a topic of wide societal importance, and will enable us to better predict how the ice sheet will change in the future. The student will lead at least three journal papers on these important science topics during the course of their PhD, and may have the possibility of undertaking a Polar field campaign. The PhD student will be based within the Centre for Polar Observation and Modelling (CPOM) at the University of Leeds, and will therefore have valuable opportunities to work with and attend meetings at the European Space Agency (ESA), and to engage with a wide range of international scientific collaborators. A studentship within CPOM provides a fantastic opportunity to actively collaborate with a large team of land and sea ice observation and modelling experts at universities across the UK. The project provides a high level of training in: (i) satellite remote sensing; (ii) polar fieldwork; (iii) glaciology; (iii) data analysis and visualization; (iv) calibration and validation of satellite systems; and (v) scientific writing. The successful applicant will have access to a broad spectrum of specialist training in Earth Observation and glaciology, in addition to the extensive University of Leeds workshops on a range of topics, including scientific programming through to managing your degree. Applicants will hold good first degree (first or high 2.1) or Masters degree in physics, maths, Earth science, climate science, Earth observation or a related discipline. Expertise in computer programming, while not required, will be a valuable asset.