Collaborative Research: IPY: POLENET/Greenland: Using Bedrock Geodesy to Constrain Past and Present Day Changes in Greenland's Ice Mass

摘要：Bevissimme-0632320 Csathosome-0632310智力焦点。这是俄亥俄州州立大学和纽约州立大学布法罗的主要研究人员的合作建议。他们将在格陵兰岛建立一个连续的GPS站网络（GNET），作为美国对国际极地年（IPY）和国际POLENET联盟的贡献的一部分。他们将使用该网络来绘制与冰后期反弹（PGR）相关的稳定垂直速度场，这将为GRACE和任何后续任务提供准确的“PGR校正”，从而抑制迄今为止最大的不确定性来源基于GRACE的格陵兰岛冰量变化估计。他们打算使用GNET来“衡量”冰量的年度和年际变化，利用地球对表面负荷变化的瞬时弹性响应，获得比GRACE更好的空间分辨率。这种方法将校准和验证相关的年度或季节性模式的负载（原因）与相邻基岩的同相季节性振荡。通过这种方式校准“称重机”后，主要研究人员将能够快速检测和分析长期冰增加或损失率的任何突然增加。与IPY的相关性：POLENET（极地地球观测网络）是一个由24个国家组成的联盟，将在IPY期间大大提高极地地区大地测量，磁力和地震数据的覆盖范围。有三个国际伙伴参与的全球冰盖网络是在格陵兰岛部署的全球冰盖网络的最大组成部分，也是北方唯一一个以主要冰盖为重点的全球冰盖网络组成部分。它将补充将由参与POLENET的12个以上国家在北极其他地方实施的全球定位系统举措。POLENET将克服地球极地地区观测系统缺乏的问题，并将提供观测基础设施和在极端环境下部署自主操作的技术能力方面的遗产。全球定位系统数据和元数据一旦进入联合国志愿人员组织档案库，将立即提供给全球科学界。POLENET项目将为北极和南极自主台站的运行开发新技术。它将促进冰川学家，大地测量学家，海洋学家，地质学家，气象学家和海洋学家在这些学科的历史上最全面的合作之一。该项目将把NASA的GRACE项目提升到一个全新的重要水平，因为为GRACE提供“PGR校正”将使其成为有史以来最强大的测量系统，用于直接观测冰盖和海洋之间的质量转移。GNET将能够探测格陵兰岛冰量增加或减少的任何快速加速，特别是在冰盖的关键边缘，以应对不断变化的气候条件。更广泛地说，了解和监测格陵兰（以及南极）冰盖的行为是一个具有巨大社会重要性的问题。人们普遍认识到，西南极或格陵兰冰盖存在着严重的危险，可能会淹没世界各地人口密集的沿海地区，从而严重损害全球经济，并破坏支持数亿人的社会基础设施。虽然在海平面上升成为严重问题之前扭转全球变暖可能为时已晚，但至关重要的是评估海平面上升的可能严重程度，以及我们的政府必须应对或缓解他们可能无力阻止的发展的时间。鉴于这一议程的重要性，我们提议利用联刚特派团的外联专家来建立一个外联部门。

ABSTRACTBevisOPP-0632320CsathoOPP-0632310Intellectual Focus. This is a collaborative proposal from Principal Investigators at Ohio State University and SUNY Buffalo. They will construct a network (GNET) of continuous GPS stations in Greenland as part the U.S. contribution to the International Polar Year (IPY) and the international POLENET consortium. They will use this network to map the steady vertical velocity field associated with postglacial rebound (PGR), which will provide GRACE, and any successor missions, with an accurate 'PGR correction', thereby suppressing by far the largest source of uncertainty in GRACE-based estimates of ice mass changes in Greenland. They intend to use GNET to 'weigh' annual and interannual changes in ice mass, obtaining better spatial resolution than GRACE is capable of, using Earth's instantaneous elastic response to surface load changes. This approach will be calibrated and validated by relating annual or seasonal patterns of loading (the cause) with in-phase seasonal oscillations of adjacent bedrock. Having calibrated a 'weighing machine' in this way, the Principal Investigators will be able to quickly detect and analyze any abrupt increases in long terms rates of ice gain or loss.Relevance to IPY: POLENET (Polar Earth Observing Network) is a consortium involving 24 nations that will dramatically improve the coverage in geodetic, magnetic, and seismic data across the polar regions during IPY. GNET, which involves three international partners, constitutes the largest component of a POLENET deployment across Greenland, and is the only POLENET component in the northern hemisphere which is focused on a major ice sheet. It will complement GPS initiatives elsewhere in the Arctic to be carried out by more than 12 nations participating in POLENET. POLENET will overcome the scarcity of observational systems in the Earth's polar regions, and will provide a legacy in observational infrastructure and in the technological capability to deploy autonomous operations in extreme environments. The GPS data and metadata will be made available to the global science community as soon as they reach the UNAVCO archive.Broader Impacts. The POLENET project will bring about the development of new technologies for operating autonomous stations in the Arctic and Antarctic. It will promote one of the most holistic collaborations between glaciologists, geodesists, geophysicists, geologists, meteorologists and oceanographers in the history of these disciplines. This project will leverage NASA's GRACE project to an entirely new level of importance, because providing GRACE with a "PGR correction" will transform it into the single most powerful measurement system ever developed for the direct observation of mass transfer between the ice sheets and the oceans. GNET will be able to detect any rapid acceleration in ice mass gain or loss in Greenland, especially at the critical margins of the ice sheet, in response to changing climatic conditions. Even more broadly, understanding and monitoring the behavior of the Greenland (as well as the Antarctic) ice sheet,is a matter of tremendous societal importance. It is widely understood that there is serious danger that the West Antarctic or Greenland ice sheets could collapse and so seriously damage the global economy, and degrade the social infrastructure supporting hundreds of millions of people, by inundating large swaths of densely inhabited coastal areas worldwide. While it may be too late to reverse global warming before sea level rise becomes seriously problematic, it is crucial to assess both the possible severity of sea level rise, and the amount of time that our governments have to respond to, or mitigate, developments that they may be powerless to prevent. Given the importance of this agenda, we propose to develop an outreach component using UNAVCO's outreach specialists.