Regional variability of ice core dust composition and provenance in Greenland

Mineralogical and isotopic composition (Sr and Nd) of six dust samples, obtained from six widely spread ice-coring sites in Greenland, were analyzed in order to investigate the regional geographic variability of dust provenance. We show that long-range transport from eastern Asian deserts provides mineral dust with essentially the same composition to all elevated interior sites (Dye 3, Site A, GRIP, and NorthGRIP), while most material deposited at sites located closer to the edge and at lower altitude (Hans Tausen and Renland) derives from proximal source regions. No contribution from other sources is apparent at any of the interior sites from the mineralogical and isotopic composition of the dust samples, each of which represents several decades of dust deposition during the 17th-18th century. These results provide additional evidence that African and North American deserts do not play a significant role in the dust deposited over Greenland, which has implications for ice core record interpretation and atmospheric dust transport model validation.