Glacial and interglacial patterns for Asian dust transport

Particle-size distributions and depositional fluxes were investigated for p resent-day Asian dust and for the late Quaternary loess/palaeosol sequences from central China. The regional-scale transport of Asian dust during inte rglacial stages is mainly attributable to non-dust storm processes and is d ominated by northwesterly surface winds. Conversely, during glacial stages the impact of dust storms on the accumulation of loess is enhanced. These r egional effects are in contrast to the global-dispersal of dust which is as sociated with transport by upper-level westerly winds and is mainly the res ult of desert dust storms during both glacial and interglacial conditions. Temporal differences in the dust transport patterns to the Loess Plateau su ggest that the variability in the coarse particle fraction (>20 mu m) durin g interglacial times is not directly attributable to the strong dust storms and dust fall events that have been linked to a strengthening of East Asia n winter monsoonal winds. This is in contrast to the dust-deposition rates which are strongly influenced by the monsoonal circulation. (C) 1999 Publis hed by Elsevier Science Ltd. All rights reserved.