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。总的来说，冰盖储存的水足以使海平面上升约6米。然而，夏天产生的表面融水是如何从冰盖上的位置流向海洋的，人们还不太清楚。两种相互竞争但并不相互排斥的理论是：1)融水渗透到冰盖的孔隙中，并储存了相对较长的时间。2)最初渗透的融水在公司的浅深度重新冻结，形成一个坚硬的锅，阻止进一步渗透。在后一种情况下，融水沿着冰盖表面迅速下坡，直到流入海洋。Rennermalm将通过实地工作、卫星遥感和建模相结合来验证这些假设。此外，Rennermalm认为，在最近的变暖期间，浅层再冻结机制在向海洋输送融水方面所起的作用比以前要小。为了探索这一假设，Rennermalm将把现代岩心的物理特征与早期探险中提取的岩心进行比较。该项目将包括研究生和本科生的培训。π吗?大学将与罗格斯大学电影局合作，确保与公众有效沟通。π吗?我们预计罗格斯大学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，在极端环境下捕捉科学研究的日常选择，并制作一个简短的多媒体叙事。海平面预计将在未来几十年上升，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水是如何流入海洋的。一种想法是，表面融水进入多孔的冰盖，在那里储存，要么重新冻结，要么以液态存在，相对较长时间。或者，正如这些研究人员提出的那样，第一批季节性融水进入浅冰，重新冻结并阻止进一步渗透，导致水迅速沿着表面冰盖向下移动，直到进入海洋。如果我们要了解未来海平面上升的速度，了解融水的命运是必不可少的。这些调查人员将整合实地工作、计算机建模和分析卫星数据。

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.