Ice Sheet - ocean interactions: Using satellite data to understand ice dynamic change

冰盖-海洋相互作用：利用卫星数据了解冰动力变化领导：安娜·e·霍格，利兹大学（UoL）联合主管：皮埃尔·迪特里厄，英国南极调查局；王赫，UoL；在过去的25年里，格陵兰岛和南极洲的冰盖使全球海平面自20世纪90年代以来上升了1.8厘米，达到了政府间气候变化专门委员会最糟糕的气候变暖情况。在格陵兰岛，冰盖的质量损失主要是夏季表面的高融化率，个别极端年份对海平面的总贡献有重大影响。卫星观测表明，南极洲的冰损失主要是由南极洲西部低洼海域的动态不平衡造成的；自20世纪40年代以来，阿蒙森海域的冰川已经变薄、加速，基准线已经退缩。南极西部的海冰加速是由暖化的环极深水（mCDW）融化浮冰的入侵所驱动的，海洋温度的年际和长期变化与厄尔尼诺-南方涛动（ENSO）相关的大气强迫有关。在未来海平面上升预估中，冰盖对全球海平面预算的贡献仍然是最大的不确定性，部分原因是受到诸如海洋冰盖不稳定性（MISI）等正反馈的驱动，而最极端的情况只有通过海洋冰崖不稳定性（MICI）的发生才有可能。为了更好地了解未来冰盖将如何变化，必须精确测量长期和新出现的动态信号。项目概述：该项目提供了一个令人兴奋的机会，可以在气候和空间科学的界面上工作，为研究气候变化的影响和影响的国际努力做出重要贡献。在这个博士学位中，您将与世界领先的地球观测专家密切合作，以更好地了解南极冰盖的变化，以及测量海洋如何影响冰融化的海洋学家。卫星地球观测彻底改变了我们对遥远和难以到达的极地地区的认识。如果没有这一关键资源，我们对哪些地区正在发生变化、事件发生的时间和速度以及驱动变化的物理机制的了解将远远不够全面。在过去的30年里，南极洲的个别冰流，如松岛冰川，自20世纪90年代初以来，速度增加了42%以上，现在已知是动态不平衡的。然而，尽管在许多地区冰速度有明显的长期增加趋势，但观测到的冰速度加快并非随时间而恒定不变，也观测到多年无显著变化。在本博士课程中，您将与卫星观测、极地海洋学和先进计算机技术方面的世界领先专家密切合作，以更好地了解南极冰盖的冰动力学。在霍格博士的监督下，你们将使用卫星观测来测量冰速，然后测量南极和格陵兰冰盖的物质平衡，量化过去30年来冰盖对海平面的贡献。合成孔径雷达（SAR）数据来自包括ERS-1/2、TerraSAR-X和Sentinel-1在内的地球观测卫星，将使用强度特征跟踪和干涉测量法来跟踪南极洲冰速的变化。在英国南极调查局（BAS）迪特里厄博士的共同监督下，你们的卫星观测将与海洋温度观测相结合，利用密封标签、系缆和自动水下航行器收集海洋温度，以便更好地了解推动这一变化的物理机制。通过利兹大学王博士的共同指导，你将率先使用先进的计算机技术，如人工智能

Ice Sheet - ocean interactions: Using satellite data to understand ice dynamic changeLead Supervisor: Anna E. Hogg, University of Leeds (UoL)Co-Supervisors: Pierre Dutrieux, British Antarctic Survey; He Wang, UoL; Adrian Jenkins Northumbria UniversityOver the last 25-years, Ice sheets in Greenland and Antarctica have raised the global sea level by 1.8 cm since the 1990's, and are matching the Intergovernmental Panel on Climate Change's worst-case climate warming scenarios. In Greenland, mass loss from the ice sheet is dominated by high rates of surface melt during the summer, with individual extreme years having a major impact on the total sea level contribution. Satellite observations have shown that ice loss from Antarctica is dominated by dynamic imbalance in the low-lying, marine-based sectors of West Antarctica; where glaciers in the Amundsen Sea Sector have thinned, accelerated, and grounding-lines have retreated since the 1940's. Ice speedup in West Antarctica is driven by incursions of warm modified Circum-polar Deep Water (mCDW) melting the floating ice, with the interannual and long-term variability of ocean temperatures linked to atmospheric forcing associated with the El Nino-Southern Oscillation (ENSO). The ice sheet contribution to the global sea level budget remains the greatest uncertainty in future projections of sea level rise, driven in part by positive feedbacks such as the Marine Ice Sheet Instability (MISI), and with the most extreme scenarios only possible through the onset of Marine Ice Cliff Instability (MICI). Both long term and emerging new dynamic signals must be accurately measured in order to better understand how ice sheets will change in the future. Project summary: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. In this PhD, you will work closely with world-leading Earth observation experts to better understand change on the Antarctic Ice Sheet, and oceanographers who measure how the ocean impacts on ice melt. 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. 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. In this PhD, you will work closely with world-leading experts in satellite observations, Polar oceanography, and advanced computer techniques, to better understand the ice dynamics of the Antarctic Ice Sheet. Through supervision by Dr Hogg, you will use satellite observations to measure ice speed and then the mass balance of the Antarctic and Greenland Ice sheets, quantifying the ice sheet sea level contribution over the last 30-years. Synthetic Aperture Radar (SAR) data, from Earth observation satellites including ERS-1/2, TerraSAR-X and Sentinel-1, will be used to track changes in ice speed In Antarctica, using intensity feature tracking and interferometry. Through co-supervision by Dr Dutrieux at the British Antarctic Survey (BAS) your satellite observations will be combined with observations of ocean temperature, collected using seal tags, moorings, and Automatic Underwater Vehicles, in order to better understand the physical mechanisms driving this change. Through co-supervision by Dr Wang at University of Leeds, you will pioneer the use of advanced computer techniques, such as Artifici