Analysis of Fog-haze Climatic Characteristics in Shijiazhuang During Recent 30 Years

摘要

The article according to the observatory materials from 1971 to 2000 of Shijiazhuang Meteorological Observatory Station, including fog-haze days' number, sunshine hours and visibility, analyzed the climatic characteristics and forming cause of fog-haze in Shijiazhuang. The results shows that in Shijiazhuang, fog-haze days were maximum in January and minimum in August, the fog-haze days in winter accounted for more than one third of the whole year's. In general, annual fog-haze days represent the increasing trend 1970s to 2000s. The change of annual fog-haze days could be divided into five stages: the fog-haze days were few and had a slowly rise trend from the earlier stage of 1970s to the middle stage of 1970s; and rapidly increasing periods from middle-later 1970s to earlier 1980s and earlier 1990s to middle-later 1990s; the descending period from the middle stage of 1980s to the earlier stage of 1990s; the second roaring period from the earlier stage of 1990s to the middle - later stage of 1990s; and decreased period from the middle -later stage of 1990s, which still kept in the relatively high level. The appearance of haze has the relationship with the local metrological condition as well as the concentration of PM10 in the atmosphere. In Shijiazhuang PMlO's particle distribution showed two peaks in 0.2μm and 1μn when the fog-haze weather showed up. PM2.5 even dominated 83% of PM10; quality concentration reached more than 250μg/m3. The article shows the forming cause of fog-haze has a consanguineous connection with the meteorological condition and the degree of polluted atmosphere.