THE ELEMENTAL SIGNATURE OF TRANSPORTED ASIAN DUST AT MAUNA-LOA-OBSERVATORY

Dust storms in Asia's interior deserts loft immense quantities of cont inental crust that are blown over the North Pacific Ocean every year. The transported mineral aerosol is first lofted and then experiences m ixing and fallout during the transport. Its elemental signature is no longer that of bulk soil. The concentration for many elements is great er in transported crust compared to bulk soil due to a difference in m ineralogy of the small crustal particle. Small particles are defined a s those below 100 mu m in diameter. The elements Al, Mg, Ca and Na do not experience an internal concentration change with particle size. Ma ny of the elements in the MLO mineral aerosol have concentrations that are greater than 1.5 times that of bulk soil. Iron, an important biol ogical agent, has twice the concentration in the MLO mineral aerosol t han in bulk soil. The elemental to Al concentration ratios observed ar e consistent, implying that the transported crustal material is below 20 mu m in diameter.