Composition, Susceptibility and Input Flux of Present Aeolian Dust Over Loess Plateau of China
黄土高原现代天然降尘的组成、通量和磁化率

Present aeolian dust is collected at 7 sites in different parts of the Loess Plateau of China. Investigation on the composition indicates that mineral dust makes up the dominant part of the dust. Magnetic susceptibility of the dust varies in range of 80~150 units (10 -8 m 3/kg), which is higher than that of glacial loess. The high susceptibility of present dust implies that original material of dust has been modified to certain extent by climatic condition. Seasonal variability of dust input flux exhibits a gentle decrease from northwest to southeast with strong seasonal variety in the northern margin of the Loess Plateau. Accumulated input flux of the dust remains consistent over most regions except for northern part where possesses obvious high input flux. Meteorological analysis on transportation and deposition process reveals that most dust material is produced in non storm deposition rather than in dust storm deposition. Aeolian dust is mainly transported by low level winds in step wise way to deposit in destination sites, and therefore its input flux offers an indicator to ground aridity of depositional as well as the source areas. Long suspension dust from desert regions plays an important role in fine port of the aeolian dust. Compared to the other seasons, dust flux resulted from winter monsoon rises obviously in the northwestern part of the Loess Plateau, whereas other parts possess limited increase of dust input.