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

摘要：

利用1960—2013年河北省11个气象站常规观测资料、1980—2013年NCEP 2.5°×2.5°再分析资料等，采用线性趋势、Morlet小波分析等方法对河北省及各地市雾、霾天气的演变特征和高空环流形势进行分析。结果表明：（1）1960—2013年11个地市中衡水市年平均雾日数最多，张家口市最少；石家庄市年平均霾日数最多，承德市最少，衡水霾日数呈下降趋势外，其他10个地市均呈上升趋势；（2）1960—2013年全省年平均雾日数呈下降趋势，霾日数呈上升趋势，且霾日数上升比雾日数下降趋势更明显；（3）河北省及各地市年平均雾日数周期性特征明显，基本都存在14 a的主振荡周期。雾、霾多发月华北上空500 hPa的纬向环流较强，环流形势利于雾、霾天气的形成和维持；雾日数与西风指数成显著的正相关关系。

关键词: 河北省, 雾霾天气, 演变特征, 环流形势