| In this thesis, aerosol number densities are measured by Laser Aerosol Particle Size Spectrometer (LAP321) carried on Dongfanghong-2 over Huang-Bo Sea in winters of 2011 and 2013. Using the number densities values, three kinds of analyses, namely, the mean aerosol size distributions, meridional distributions of aerosol number density over Yellow Sea and effects of meteorological conditions, are mainly studied. At the same time, total aerosol size distributions of atmospheric column are retrieved with aerosol optical thickness (AOT) data from MODIS. The main research contents and results in this thesis can be divided into three major parts:1. The following conclusions can be drown from The size distribution of actual measurement:(1) Aerosols number densities in two ranges, namely,0.30μm<D<0.34 and 2μm<D<8μm, over Bohai Sea are obviously greater than that of Yellow Sea; (2) Generally speaking, there is a regular that meridional distribution of Yellow sea aerosols, that is to say, aerosols number densities of Yellow Sea become bigger from low latitude to high latitude; (3) Wind speed is one of the important causes of aerosols, and aerosol number densities increase with wind speed when it is less than 12m/s. (4)The daily aerosol number densities change as an undulant curve, and there is a peak value appeared at 00:00.2. The columnar aerosol size distributions over Huang-Bo Sea are derived with AOT data from MODIS. The wavelengths of the AOT data are 470 nm,550 nm,660 nm,860 nm,1240 nm,1630 nm and 2130 nm. And then the inversion results are evaluated. The result shows that when parameter v* in the fast function is 2.0, the deviation between inversion values and true value is large; When taking 4.0, inversion spectrum is rough, inversion values bounce slightly; And when taking the two values above, negative values in the inversion of fast variable function is getting more, in any inversion regions with the size of 0.1°×0.1°, inversion columnar aerosol size distributions aren’t easy to get. As a result, taking 3.0 for the fast function parameter, the final size distribution is showed more close to reality. And it is the optimal choice to this inversion algorithm.3. Based on the atmospheric aerosol size distributions inverted with AOT data of MODIS from 2010 to 2014, the regulation of aerosol number density distributions over Huang-Bo Sea are concluded seasonally and regionally. The results show that the accumulation mode of aerosol number density is 2-3 times of magnitude higher than that of coarse modal in average; the two modes of aerosols in the offshore area have large values than the open sea area; Accumulation mode of aerosol number density has highest value in winter, and lowest in summer near Lianyungang, by contrast, the coarse modal is higher in spring and winter, and lower in summer and fall at this region; besides, In Bohai Bay, the regular is different, namely, all the accumulation modes of aerosol number density in the four seasons are high, and all the coarse mode are low. At last, in the analysis of aerosol number density in 2010-2013, a maximum numeric of accumulation mode of aerosol number density is found by the north Yellow Sea, Bohai Sea and Lianyungang, a highest value in 2010 and a lowest value in 2011 are developed. In addition, the value is getting down slightly in 2013. |
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