关键词: 河北省, 雾霾天气, 演变特征, 环流形势

Abstract:

Based on conventional meteorological data of 11 stations in Hebei Province during 1960-2013, NCEP reanalysis data with 2.5°×2.5°spatial resolution during 1980-2013, the change characteristics of fog and haze days in 11 cities of Hebei Province were analyzed by using linear trend analysis and Morlet wavelets methods. The results are as follows: (1) There was most fog days in Hengshui among 11 cities of Hebei Province during 1960-2013, and it was  least in Zhangjiakou. The fog days in 7 cities showed a downward trend, and in 3 cities it showed an upward trend. There was most haze days in Shijiazhuang during 1971-2013, and it was least in Chengde. Except for Hengshui, in the other 10 cities it was on the rise. (2) The annual-average fog days showed a decreasing trend in Hebei Province during 1960-2013, but annual-average haze days showed an increasing trend during 1971-2013. (3) Annual average fog days in the whole Hebei Province and each city showed an obvious periodical change characteristic, and the primary period was 14 a in most cities of Hebei Province. There was strong zonal circulation on 500 hPa over North China in months with more hazy and fog days, which was conducive to the formation and maintenance of fog and haze weather. There was a significant positive correlation between fog days and the westerly index, the correlation coefficient was 0.57.

Key words: Hebei Province, fog and haze, change characteristics, atmospheric circulation