Tracking and prediction of the path of the Giant Pine Island iceberg

自2011年11月以来，人们已经知道，在不久的将来，一座大约30公里长的巨大冰山可能会从松树岛冰川（南纬75度，西经100度）上断裂，进入南极洲西部的阿蒙森海。这种情况现在已经发生（2013年7月9日），冰山将很快在南极海岸流中开始向西移动，朝向罗斯海。这是自2001年以来第一个从松岛冰川崩解的巨大冰山。乍一看，它可能的初始轨迹不会引起环境问题，除了南极洲西部周围淡水流量缓慢而持续地增加之外，该地区没有主要的深水形成。然而，这个位置之前的一个巨大冰山最终加入了南极绕极流（ACC），并通过德雷克海峡进入南大西洋，因此潜在地构成了航行危险，并成为靠近重要深水和中间水形成区域的上层海洋淡水来源。在这份紧急提案中，我们打算追踪这座冰山，但更重要的是，也要预测它可能的路径和超出拨款期限的环境影响，因为它的生命周期可能会延长数年而不是数月。我们将使用谢菲尔德大学开发的ITSARI冰跟踪软件算法来跟踪和描述巨大冰山的面积（和分裂）的演变，并使用南安普顿大学开发的海洋-冰山耦合模型NEMO-ICB来预测冰山在数月至数年内的路径。我们预计，这将为冰山的释放对航行或海洋学造成的任何后果提供及时的警告，同时也将测试一种技术，以便以后由冰害警报服务机构实施。

Since November 2011 it has been known that a giant iceberg, some 30 km long, is likely to break off Pine Island glacier (75S, 100W) into the Amundsen Sea off west Antarctica in the near future. This has now occurred (9 July 2013) and the iceberg will soon begin to move westwards in the Antarctic Coastal Current towards the Ross Sea. This is the first such giant iceberg to calve from Pine Island glacier since 2001. Its likely initial trajectory, at first sight, does not raise environmental issues apart from a slow and persistent increase in the freshwater flux around west Antarctica, an area without major deep water formation. However, a previous giant iceberg from this location eventually joined the Antarctic Circumpolar Current (ACC) and passed through the Drake Passage, entering the South Atlantic and so potentially posing both a navigation hazard and a source of upper ocean freshwater close to regions of significant deepwater and intermediate water formation.In this Urgency proposal we intend to track this iceberg, but, more importantly, to also predict its likely path and environmental impact beyond the duration of a grant, as its lifetime is likely to extend over years rather than months. We will use the ITSARI ice tracking software algorithm, developed at the University of Sheffield, to track and describe the evolution of area (and break-up) of the giant iceberg, and the coupled ocean-iceberg model NEMO-ICB, developed at the University of Southampton, to predict the iceberg's path over months to years.We anticipate that this will provide a timely warning of any navigation or oceanographic consequences of the iceberg's release, but also test a technique for later implementation by ice hazard warning services.