Collaborative Research: Understanding GrIS moulin hydrology and links to ice motion

格陵兰冰盖的融化并不是一个简单的问题，温暖的空气温度融化了表面的冰，然后流入海洋。 表面融水可以通过被称为冰川穴的天然管道流入冰川深处。 这些地下通道不仅将水输送到某个出口，在那里它流入海洋，而且还可能影响冰川向海洋的下坡滑动。 为了更好地了解冰川滑动的控制，PI？我们建议对格陵兰冰盖进行实地和模型研究。 私家侦探？s将用压力传感器对一些穴城进行检测。 冰川速度将用GPS传感器测量。 将通过染料示踪监测出院。 模拟将进行整合的意见与一些简单的？管道？除了对研究生和本科生进行培训外，PI还将与阿肯色州大学的一名新闻系学生合作，制作一部关于他们实地经验的纪录片。这种合作提供了一个独特的机会，沟通给广大公众。据认为，增加渠道减少冰下水压力的行为，以缓冲格陵兰冰盖（GrIS）对冰速度大幅增加。然而，很少有测量的水压力已经在渠化冰下排水系统，以测试这一假设。私家侦探？s将获得天气学上的冰上河流流量数据，冰川的水位和冰速度在两个冰川的网站沿着在帕基措格地区的冰流线。 数据将被分析，并用于参数化模型实验，以确定在何种程度上：1）当地与区域输入的融水控制冰臼水位; 2）发生在沿着冰流路径的有效压力的变化影响冰下水压力和冰速度之间的局部关系。

The Melting of the Greenland ice sheet is not a simple issue of warmer air temperatures melting the surface ice, which then flows into the ocean. Surface meltwater can flow deep into the glacier through natural pipes known as moulins. These subsurface channels not only transmit water to some outlet, where it flows into the ocean, but may also influence the downslope sliding of the glacier toward the ocean. To better understand the controls that govern glacier sliding, the PI?s propose to conduct field and model studies on the Greenland ice sheet. The PI?s will instrument a number of moulins with pressure sensors. Glacier velocity will be measured with GPS sensors. Discharge will be monitored through dye tracing. Simulations will be conducted to integrate the observations with a number of simple ?conduit? models in the hope of providing a better and more comprehensive understanding of the processes that govern glacier sliding.Beyond the training of graduate and undergraduate students, the PIs will work with a journalism student at the University of Arkansas to produce a documentary about their field experience. This collaboration provides a unique opportunity to communicate to the general public.It is thought that increased channelization reduces subglacial water pressure act to buffer the Greenland Ice Sheet (GrIS) against large increases in ice velocity. However, few measurements of water pressure have been made in channelized subglacial drainage systems to test this hypothesis. The PI?s will obtain synoptic supraglacial stream discharge data, moulin water level and ice velocity at two moulin sites along an ice flow line in the Paakitsoq Region of the GrIS. Data will be analyzed, and used to parameterize model experiments, to determine the degree to which: 1) local versus regional inputs of melt water control moulin water levels; 2) changes in effective pressure that occur along ice flow paths affect local relationships between subglacial water pressure and ice velocity.