Reconstructed volcanic stratospheric sulfur injections and volcanic sulfate deposition over Greenland and Antarctica for the Bølling-Allerød/Younger Dryas transition (13.20-12.80 ka BP)

We used four polar ice cores - two from Greenland and two from Antarctica - to investigate volcanic sulphate deposition on polar ice sheets between 13,200 and 12,800 years BP. From Greenland, we employed discrete sulphate measurements from the Greenland Ice Sheet Project Two (GISP2; 72.97°N, 38.80°W) ice core (Mayewski et al., 1997) as well as sulphate measurements using Continuous Flow Analysis (CFA) (Bigler et al., 2002; Bigler et al., 2011) from the North Greenland Ice Core Project (NGRIP; 75.10°N, 42.33°W; 2941 m a.s.l.). From Antarctica, we used Fast Ion Chromatography (FIC) measurements from the EPICA Dronning Maud Land (EDML; 75.00°S, 00.07°E; 2892 m a.s.l.) ice core (Severi et al., 2007) as well as sulphur measurements (converted to sulphate) using Continuous Flow Analysis (CFA) coupled to an inductively coupled plasma mass spectrometer (ICPMS) (McConnell et al., 2017) from the WAIS (West Antarctic Ice Sheet) Divide ice core project (WD; 79.48°S, 112.11°W, 1766 m a.s.l.) (Sigl et al., 2016). The time resolution of the data range between multi-annual (i.e. 4 years) for GISP2 to sub-annual for NGRIP and WD. Based on these ice cores and by applying the age synchronization lattice previously developed for these cores (Seierstad et al., 2014; Buizert et al., 2018; Svensson et al., 2020) with linear interpolation between the volcanic markers, we reconstructed volcanic sulphate deposition over Greenland and Antarctica using established methods (Sigl et al., 2014; Sigl et al., 2015). Using the methodology developed and applied to a similar network of ice cores over the past 2,500 years (Toohey & Sigl 2017) we further estimated stratospheric sulphur injection (SSI) from 30 eruptions with SSI in excess of 1 Tg S.