沙尘天气强度特征指数研究--以北京地区为例

A comprehensive index for quantifying dust event intensity

利用1970-2000年北京及其周边地区以及影响北京沙尘天气的上风向共14个基准气象站的沙尘天气与相关气象因子资料,分析了沙尘天气与各因子之间的相关性。研究发现,风速、相对湿度与沙尘天气的相关关系最显著;同时,对能见度与沙尘浓度观测值的分析得出,二者存在非线性关系。在上述分析的基础上,用能见度、风速、相对湿度构建了沙尘强度特征指数,该指数与这3个因子均呈非线性关系,指数值越大表示沙尘天气强度越大,反之,指数值越小表示沙尘天气强度越小。经验说明,沙尘强度特征指数与相应沙尘浓度观测值有着较一致的变化趋势,该指数从气象和环境两个方面反映了沙尘天气的强度特征。

There is increasing attention focused on the dust events, which bring influence to the environment. The dust events are not only meteorological phenomena but also environmental problem. What extent and relationship between various relative factors and the dust events intensity is a challenging subject on the dust events research fields. Relationship between dust event and relevant meteorological factors are presented on basis of analyzing the meteorological data in Beijing and other 13 typical weather stations located in the dust events route to Beijing from 1971 to 2000. Results show there are significant relationship of wind velocity and relative humidity with the dust events frequency. At the same time, the relationship between the atmosphere visibility and TSP is analyzed. The result implies that they are nonlinear relationship. The dust intensity index is established on basis of above analytical results by using the wind velocity, relative humidity and visibility. The index has non - linear relationship with the three factors. The larger index means the dust event is stronger, and the small index means weak dust event. The dust intensity index involves meteorological and environmental factors, which supplies a quantitative method for the intensity character of dust events and correlated evaluation of environment.