Greenland Ice Sheet Project Two (GISP2) ice core methane (CH4) and nitrogen isotopic composition (d15N-N2), 13-50 ka BP

We present high resolution measurements of atmospheric methane (CH4) and nitrogen isotopic composition (d15N-N2) in the Greenland Ice Sheet Project Two (GISP2) Ice core. The data span Marine Isotope Stage 3, 13 to 50 thousand years (ka) before present. These datasets enhance our understanding of abrupt climate variability during the last glacial period, with a focus on Heinrich events 1 through 5. CH4 data were analyzed between 2014 and 2020 via an established wet extraction technique (Mitchell et al. 2013). Concentrations were determined via gas chromatography measurements on an Agilent 6890N and calibrated to the NOAA04 scale. d15N-N2 data were measured between 2017 and 2020 on a Finnigan MAT Delta XP via an established technique (Petrenko et al. 2006). The methane data allow for gas-phase synchronization of the GISP2 ice core to other polar ice cores from Greenland and Antarctica. The nitrogen isotopic composition data allow for reconstruction of abrupt Greenland surface climate variations.本研究提供了格陵兰冰芯计划2号（Greenland Ice Sheet Project Two, GISP2）冰芯中大气甲烷（CH₄）与氮同位素组成（δ¹⁵N-N₂）的高分辨率测量数据。该数据集覆盖了距今13至5万年的海洋同位素阶段3（Marine Isotope Stage 3），有助于加深我们对末次冰期期间气候突变变率的理解，研究重点聚焦于赫里希事件（Heinrich events）1至5号。甲烷数据于2014至2020年间通过成熟的湿法萃取技术（Mitchell等，2013）完成分析，其浓度通过安捷伦6890N（Agilent 6890N）气相色谱仪测量得到，并校准至NOAA04标准尺度。δ¹⁵N-N₂数据于2017至2020年间通过成熟的实验方法（Petrenko等，2006）在Finnigan MAT Delta XP质谱仪上完成测定。甲烷数据可实现格陵兰与南极其他极地冰芯与GISP2冰芯的气相同步定年，而氮同位素组成数据则可用于重建格陵兰地表气候的突变过程。