Se concentrations ranged from to xA pg g with

Atmospheric Al concentrations in Greenland usually exhibit strong peaks in spring associated with Asian dust episodes (Candelone et al., 1996 and Barbante et al., 2003). In this RN 1 study, pronounced Al peaks were observed at 9.1–13.7, 160.0–164.6, 205.7–210.3, and 306.3–310.9 cm and relatively weak peaks at 68.6–73.1, 105.1–109.7, and 274.3–278.9 cm (Table S2 and Fig. 2). The peaks generally occurred in snow layers deposited slightly later than winter as defined by δ18O minima, indicating that these depth intervals corresponded to spring. Seasonal variation in Na+ concentration derived from sea salt are characterized by winter–spring maxima and mid-summer minima in interior Greenland aerosols and snow (Mosher et al., 1993 and Dibb et al., 2007). After subtracting the Na concentration from crustal dust using the Al concentrations in each sample (Wedepohl, 1995), the sea-salt-Na+ (ss-Na+) concentrations in our snow samples exhibit strong peaks in the transition from winter to spring as inferred from δ18O and Al, except for the 32.0–36.6 cm and 41.1–45.7 cm depth intervals. Similar poorly defined peaks for chemical species were previously reported in a central Greenland snow profile (Mayewski et al., 1990 and Barbante et al., 2003).