中文摘要：

首先分析了北京2002年3月一次强沙尘天气过程的阵风结构，对其进行了分形特征的分析，比较不同高度层上分数维的变化，不同时间尺度阵风概率分布的标度关系，以及无阵风时间尺度概率分布的标度与分数维存在的联系。更进一步，分析了2002年全年的阵风分形特性、3月的分形特征以及其他天气现象（如降雨）的分形特征比较后，发现：1）小尺度阵风结构的分数维要高于大尺度阵风分数维，这是因为小尺度阵风包含了更多短时局部的天气信息；2）不同高度、不同时间尺度阵风的分数维存在较大差异，而不是象湍流脉动时间序列的分数维那样随时问基本不变；3）因受天气形势的影响大，中尺度阵风的分数维虽基本相同，但由于大尺度阵风较少，其概率分布不存在标度关系，这同样也在其他天气现象（如降雨）中存在；4）无阵风时间尺度概率分布的标度与分数维之间的联系，一方面反映在其标度指数上，另一方面反映在其标度区间上。

英文摘要：

We first investigate a typical case of serious gustwind （March, 2003 in Beijing） by the use of wind speed series recorded by the Beijing 325 m Meteorological Tower. The structure, especially the fractal characteristic of the gustwind can be very well and very clear represented by the fractal theory, which leads to some essential information about such phenomenon. Then we also investigate all cases of gustwind as well as turbulence, raining weather and weak wind （in such case there is no gustwind） in the whole year 2002. The comparisons reveal： 1） The wind gustness appears when the basic flow （e. g. , ten minutes averaged velocity） and the perturbations （fluctuations） both are strong. It perhaps can be explained by the non-linear interactions between large-scale structure （ten minutes average velocity） and the perturbations （original data）. 2） As the fractal dimensions of the wind gustness on different heights are calculated, there is often a turning point in the fractal dimensions at the time scale of 16.7 hours. It means the wind gustness is multi-fractal. 3） The fractal dimensions of different gustwind are different, unlike the turbulence whose fractal dimension is almost in 1.6--1.7. It means the wind gustness is anisotropy but not isotropy as turbulence. 4） By analyzing no gustness of wind and comparing with gustwind time scales, we also find that there are two relationships between the probabilities with fractal dimensions.