Numerical Studies On Radiative Effects Of Dust Aerosol

Based on the integration of abundant observed research results of the basiccharacteristics of the dust aerosol originated from north china, a model on dustaerosol' basic characteristics(including size distribution, vertical distribution andrefractive indices)is given for sensitive experimentation research on solar radiativeeffects. When dust storms occur, not only the number concentration increasesobviously, the peak value of size distribution excurses to coarse particles, but alsodust particles' physical and chemistry property will change, such as sulfuration, andresult in the changes of its refractive indices and scale. Besides, coarse particlesproportion is greater than other aerosols, due to gravitation sedimentation, sizedistribution become narrow along with the altitude more obviously, the relationbetween dust aerosol optical property and these affective factors is investigatedthrough Mie theory, and the influence of the different characteristics of dust aerosolson solar radiation heating rate is investigated by radiation transportation model.The coefficients of dust aerosol' absorption, scatter and extinction arepositively correlative to concentration. When the concentration is small, the profileof heating rate is similar to vertical distribution. When the concentration is morelarger, the heating rate increases obviously along with increasing of concentration,the greatest influence on heating rate occurs in lower than the central section oftroposphere, where concentration is less than ground; sulfuration have a similarinfluence on particles' optical properties and radiative effects with concentration, thisinfluence may assimilate to two times concentration; these changes of sizedistribution all have some influence on dust optical properties and its solar radiativeeffects.