Dust at the Poles during the Past Three Millennium: Linkages to Climate and Land Use

Abstract:

Continental dust plays an important role in climate forcing, by interacting with incoming solar and outgoing long wave radiation and by impacting albedo when deposited on bright surfaces such as fresh snow. Continental dust may also play an important role in ocean fertilization and carbon sequestration. Because the lifetime of dust aerosol in the atmosphere is only on the order of days to weeks, spatial and temporal variability in concentrations and fluxes is high and understanding of recent and long term changes is limited. Therefore, understanding of natural variations and climate drivers of continental dust, and potential climate feedbacks on longer timescales is critical.

Here we present and discuss continuous, high depth resolution measurements of a range of dust proxies in high latitude ice cores from the Arctic and Antarctic. Sub-annually resolved measurements provide insights into the temporal variations in dust deposition. Included are traditional proxies such as non-sea-salt (nss) calcium and insoluble particle number and size distribution as well as less traditional proxies such as rare earth elements which together provide important insights into how dust sources and transport may have changed in the past. We compare these detailed dust records with climate and land use proxies to investigate drivers of dustiness during the last three millennium.