14C and 10Be in Dust Deposited During the Storm of 16–17 April 2006 in Beijing

Abstract

The concentrations of 10Be and 14C and values of δ13C in samples collected during a major dust storm in Beijing on 16–17 April 2006 were studied. The 10Be concentrations ranged from 1.69 × 108 to 2.07 × 108 atom/g, 14C ages for black carbon (BC) ranged from 3001 to 5181 yr BP and for total inorganic carbon (TIC) from 8464 to 9119 yr BP, and δ13C values for BC ranged from -23.15% to -23.80% and for TIC from -5.39% to -5.98%. A comparison of BC content and δ13C value between the dust, surface soil in the dust source region, and aerosols in Beijing indicated that BC in the dust deposited in Beijing is significantly incorporated by aerosol BC during the dust transportation. Based on the 14C ages of BC, the proportion of fossil-fuel-derived BC was 0.35–0.49 of the total. In contrast to BC, the TIC deposited in Beijing can be firmly related to the source area and δ13C was not significantly modified during its transportation. According to the 14C ages of TIC, the proportion of the secondary carbonate in the dust was from 0.63 to 0.70. The results confirm that 14C of TIC is another useful tracer to indicate the source region of dust besides the content and δ13C value of TIC from the arid and semi-arid regions of China.