Fig. 3: Iodine and sodium merged record from Dome C.
From: Antarctic ozone hole modifies iodine geochemistry on the Antarctic Plateau
The upper panel shows the merged 1-year smooth records (see S3.5 in the SM for details) using snow pits and ice core data (iodine merged in black— IM - and sodium merged in red—NaM). Light grey and red lines show the raw data, and red and bold curves show the 5-year smoothing. The lower panel shows the iodine enrichment (Ienr = I/(Na*0.00000568, where 0.00000568 is the I/Na mass ratio in seawater), where the solid green line shows the 5-year smoothing. The dashed vertical line indicates the tipping point discontinuity at 1975 CE.
