NGRIP ice-core volcanic sulfate concentration and deposition from 79.14 to 80.48 ka BP

We present continuous records of 1 cm resolved sulfate concentrations, insoluble particle number and mass concentration, and liquid conductivity using a Continuous Flow Analysis (CFA) system (Bigler et al., 2002; Bigler et al., 2011; Erhardt et al., 2022) from the North Greenland Ice Core Project (NGRIP; 75.10°N, 42.33°W; 2941 m a.s.l.) and estimated volcanic sulfate mass depositions for the time period 79.14 and 80.48 ka BP on the GICC05modelext chronology, transferred to the AICC2012 chronology (Veres et al., 2013; Seierstad et al., 2014) using a common volcanic marker in EPICA Dome C ice core dated 79.51 ka BP. The reconstruction is based on sulfate measurements employing high-resolution continuous flow analysis. Volcanic eruptions are detected when annual sulfate concentrations exceeded the background concentrations + 4 times the median of the absolute deviation. Background concentrations are estimated using a 181-point running median. Volcanic sulfate deposition rates are calculated by subtracting the background concentrations from total sulfate concentrations using thinning corrected estimates of mean ice accumulation rates at the ice-core site.

我们提供来自北格陵兰冰芯计划（North Greenland Ice Core Project，NGRIP；北纬75.10°，西经42.33°；海拔2941米）的连续记录，包括分辨率为1厘米的硫酸盐浓度、不溶性颗粒数量及质量浓度、液体电导率，这些数据通过连续流动分析（Continuous Flow Analysis，CFA）系统获取（Bigler et al., 2002；Bigler et al., 2011；Erhardt et al., 2022）；同时提供基于GICC05modelext年表估算的79.14至80.48千年BP期间火山硫酸盐质量沉积量，该年表通过EPICA Dome C冰芯中年代为79.51千年BP的共同火山标志物转换至AICC2012年表（Veres et al., 2013；Seierstad et al., 2014）。

本重建工作基于采用高分辨率连续流动分析的硫酸盐测量数据。当年硫酸盐浓度超过背景浓度加4倍绝对偏差中位数时，即判定为火山喷发事件。背景浓度通过181点滑动中位数法估算。