Fig. 3: Comparison of volcanic forcing, solar activity, sea-ice variability, and Bàsura record.
From: Split westerlies over Europe in the early Little Ice Age
a Global volcanic aerosol forcing16. b Violet: concentration of benthic foraminifera from the North Greenland shelf (PS2641-4; Supplementary Fig. 2) as an indicator of sea-ice cover50. Pink: ice-rafted debris (IRD) (MSM5/5; Supplementary Fig. 2) from the Fram Strait49. High values of these two records denote large sea-ice cover. c Five-point averaged diatom concentration (Thalassiosira nordenskioeldii) from the west Greenland shelf (GA306-4; Supplementary Fig. 2)51. High value denotes large sea-ice cover. d Red: 40-year smoothed reconstructed late summer Arctic sea-ice extent56. e Bàsura Sr/Ca record. f Reconstructed NAO index11. g Total solar irradiance12. The intervals of the Spörer Minimum (1388–1558 C.E.)12 and decreased sea-ice event (1450–1620 C.E.)56 are marked. The grey vertical bar denotes the Little Ice Age. The yellow vertical bar highlights the period 1470–1610 C.E.
