Chemical measurements in the Arctic Circle Traverse 2011 (ACT11) ice cores

Net snow accumulation is the largest single component and the sole input to the Greenland ice sheet mass budget. To map spatial and temporal changes in high net snow accumulation regions of the southeast Greenland ice sheet during the past 5 decades, two surface traverses were undertaken in 2010 and 2011. The NSF-funded traverses were called Arctic Circle Traverse (ACT)10 and ACT11 and included detailed measurements of surface elevation and ice penetrating. A small array of shallow ice cores was collected and analyzed using the continuous analytical system at the Desert Research Institute. The measurements primarily were intended to allow for accurate dating of annual layers and so to determine past net annual snow accumulation, as well as age scales for the radar surveys.

净积雪积累量（net snow accumulation）是格陵兰冰盖质量收支预算中占比最大的单一组成部分，同时也是该预算的唯一输入项。为了绘制过去50年间格陵兰冰盖东南部高净积雪积累区的时空变化图谱，研究团队于2010年与2011年先后开展了两次地表穿越考察。这两项由美国国家科学基金会（National Science Foundation, NSF）资助的考察项目分别命名为北极圈穿越考察（Arctic Circle Traverse, ACT）10号与ACT11号，考察期间完成了高精度的地表高程与冰穿透探测测量工作。研究团队同时采集了一组小型浅冰芯样品，并借助沙漠研究所（Desert Research Institute）的连续分析系统开展了检测分析。本次测量的核心目标在于精准定年冰芯年纹层，以此确定过往的年净积雪积累量，同时为雷达探测工作建立年代标尺。