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，气温升高使表面的冰融化，然后流入海洋。地表融水可以通过被称为冰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，在那里水流入海洋，而且还可能影响冰川向海洋的下坡滑动。为了更好地理解控制冰川滑动的因素，PI？我们建议对格陵兰冰盖进行实地和模型研究。π吗?美国将用压力传感器对一些冰穴进行测量。冰川速度将用GPS传感器测量。排放将通过染料追踪来监测。将进行模拟，将观测结果与一些简单的导管相结合。这些模型希望能对控制冰川滑动的过程提供更好、更全面的理解。除了对研究生和本科生进行培训之外，这些pi还将与阿肯色大学（University of Arkansas）的一名新闻系学生合作，制作一部关于他们实地经历的纪录片。这种合作提供了一个与公众交流的独特机会。据认为，增加的水道化减少了冰下水压，缓冲了格陵兰冰盖（GrIS）对冰速大幅增加的影响。然而，在水道化的冰下排水系统中，很少有水压测量来验证这一假设。π吗?s将在GrIS的Paakitsoq地区沿冰流线的两个冰坑站点获得冰上水流流量的天气性数据、冰坑水位和冰速度。将对数据进行分析，并将其用于参数化模型实验，以确定：1)融水的局部和区域输入对冰穴水位的控制程度；2)冰流路径上有效压力的变化会影响冰下水压与冰速的局部关系。

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.