Collaborative Research: Refreezing in the firn of the Greenland ice sheet: Spatiotemporal variability and implications for ice sheet mass balance

北极正在变暖，格陵兰冰盖正在融化。总体而言，冰盖储存的水足以使海平面上升约6米。然而，夏季产生的表面融化水是如何从冰盖上的位置进入海洋的，目前还不清楚。两种相互竞争但并不相互排斥的理论是：1)融化的水渗入冰盖的毛孔，并储存相对较长的时间。2)最初渗入的融水在坚固的浅层重新冻结，形成一个坚硬的锅，阻止进一步的渗透。在后一种情况下，融化的水沿着冰盖表面快速向下移动，直到流入海洋。RennerMalm将通过实地工作、卫星遥感和建模的组合来验证这些假设。此外，雷纳马尔姆认为，在最近一次变暖期间，浅层再冻结机制在向海洋输送融化水方面发挥的作用比以前要小。为了探索这一假设，RennerMalm将比较现代岩心和早期探险中提取的岩心的物理特征。该项目将涉及研究生和本科生的培训。皮？S将与罗格斯电影局合作，确保与公众的有效沟通。皮耶罗？S预计，罗格斯电影局局长将寻求在电影节和其他场所展示这部纪录片。在第一年，罗格斯大学电影局的两名成员(导演和一名学生)将前往格陵兰岛，捕捉极端环境下科学研究的日常选择，并制作简短的多媒体叙事。海平面预计将在未来几十年内上升，部分原因是格陵兰冰盖的融化。然而，我们并不完全了解冰盖表面产生的融化水是如何进入海洋的。一种思路是，表面融化的水进入了多孔的冰盖，在那里它被重新冻结或以液体状态储存了相对较长的时间。或者，正如这些研究人员所建议的那样，第一批季节性融化的水进入浅层冰，重新冻结并阻止进一步的渗透，导致水迅速沿着表面冰盖流动，直到进入海洋。如果我们想要了解未来海平面上升的速度，了解融化水的命运是必不可少的。这些调查人员将整合野外工作、计算机建模和分析来自卫星的数据。

The Arctic is warming and the Greenland ice sheet is melting. In total, the ice sheet stores enough water to raise sea level by approximately 6 meters. However, how surface meltwater generated in the summer makes its way from its location on the ice sheet to the ocean is not well understood. Two competing but not mutually exclusive theories are 1) the meltwater percolates into the ice sheet pores and is stored for a relatively long time. 2) The initial infiltrating meltwater refreezes at shallow depth in the firm, forming a hard pan that prohibits further infiltration. In this latter case, the meltwater quickly moves downslope along the surface of the ice sheet until it drains into the ocean. Rennermalm will test these hypotheses through a combination of field work, remote sensing from satellites, and modeling. Moreover, Rennermalm believes that during the most recent warming, the shallow refreezing mechanism has been playing a lesser role in the delivery of meltwater to the ocean than in previous times. To explore this hypothesis Rennermalm will compare the physical characteristics of modern cores with those extracted from earlier expeditions.The project will involve graduate and undergraduate student training. The PI?s will collaborate with the Rutgers Film Bureau to ensure effective communication with the public. The PI?s expect that the Rutgers Film Bureau director will seek to showcase the documentary at film festivals and other venues. In year one, two Rutgers Film Bureau members (the director and one student) will travel to Greenland to capture the day-to-day choices of scientific research in an extreme environment and produce a short multimedia narrative. Sea level is expected to rise in the decades to come, partially due to the melting of the Greenland ice sheet. However, we do not fully understand how meltwater generated on the surface of the ice sheet makes its way to the ocean. One line of thinking is that surface meltwater makes its way into the porous ice sheet where it is stored, either refrozen or in a liquid state, for relatively long times. Alternatively, as proposed by these investigators, the first seasonal meltwater that makes its way into the shallow ice, refreezes and blocks further infiltration, resulting in water that quickly moves down the surface ice sheet until it enters the ocean. Knowing the fate of meltwater is imperative if we are to understand how fast sea level will rise in the future. These investigators will integrate field work, computer modeling, and analyze data from satellites.