Dust can affect the radiative balance of the atmosphere by absorbing or reflecting incoming solar radiation and it can be a source of micronutrients, such as iron, to the ocean. It has been suggested that production, transport, and deposition of dust is influenced by climatic changes on glacial-interglacial timescales. Here we present a high-resolution aeolian dust record from the EPICA Dome C ice core in East Antarctica, which provides an undisturbed climate sequence over the last eight climatic cycles. We find that there is a significant correlation between dust flux and temperature records during glacial periods that is absent during interglacial periods. Our data suggests that dust flux is increasingly correlated with Antarctic temperature as climate becomes colder. We interpret this as progressive coupling of Antarctic and lower latitudes climate. Limited changes in glacial-interglacial atmospheric transport time Mahowald et al. (1999, doi:10.1029/1999JD900084), Jouzel et al. (2007, doi:10.1126/science.1141038), and Werner et al. (2002, doi:10.1029/2002JD002365) suggest that the sources and lifetime of dust are the major factors controlling the high glacial dust input. We propose that the observed ~25-fold increase in glacial dust flux over all eight glacial periods can be attributed to a strengthening of South American dust sources, together with a longer atmospheric dust particle life-time in the upper troposphere resulting from a reduced hydrological cycle during the ice ages.

This work is a contribution to the "European Project for Ice Coring in Antarctica" (EPICA), a joint ESF (European Science Foundation)/EC scientific programme, funded by the European Commission and by national contributions from Belgium, Denmark, France, Germany, Italy, the Netherlands, Norway, Sweden, Switzerland and the United Kingdom. We acknowledge long-term financial support by the Swiss NSF, the University of Bern and the Swiss Federal Agency of Energy, and EC Project EPICA-MIS.

Supplement to: Lambert, Fabrice; Delmonte, Barbara; Petit, Jean Robert; Bigler, Matthias; Kaufmann, Patrik R; Hutterli, Manuel A; Stocker, Thomas F; Ruth, Urs; Steffensen, Jørgen Peder; Maggi, Valter (2008): Dust-climate couplings over the past 800,000 years from the EPICA Dome C ice core. Nature, 452, 616-619