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

格陵兰冰盖的融化不是一个简单的问题，因为气温升高会融化表面的冰，然后这些冰就会流入海洋。地表融化的水可以通过被称为冰川的天然管道流入冰川深处。这些地下渠道不仅将水输送到某个出口，在那里流入海洋，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因素，皮？S建议对格陵兰冰盖进行实地和模型研究。皮？S将用压力传感器测量多个滑雪板。冰川速度将用GPS传感器测量。将通过染料追踪来监测排放情况。将进行模拟，以将观测结果与一些简单的管道？除了对研究生和本科生的培训外，PI还将与阿肯色大学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。这一合作提供了一个与公众交流的独特机会。人们认为，增加的沟道化降低了冰层下的水压力，起到了缓冲格陵兰冰盖(GRI)免受冰速大幅增加的作用。然而，在沟道化的冰川下排水系统中，很少有水压力的测量来验证这一假设。皮？S将获得GRIS Paakitsoq地区沿冰流线的两个Moulin站点的冰上河流流量、Moulin水位和冰速度的天气学资料。将对数据进行分析，并将其用于模型实验的参数化，以确定：1)融化水的局部和区域输入控制冰川水位；2)沿冰流路径发生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.