For data of atmospheric composition missing, fog and haze days were distinguished based on the standard of meteorological industry Observation and Forecasting Levels of Haze （QX/T113-2010） and four user-defined stan...For data of atmospheric composition missing, fog and haze days were distinguished based on the standard of meteorological industry Observation and Forecasting Levels of Haze （QX/T113-2010） and four user-defined standards, and using data of surface meteorological factors in Fuzhou City, China from 2005 to 2011, temporal distributions of fog and haze days were analyzed respectively to provide methods for fog and haze forecast. The results showed that there were 28.9 fog days and 89.7 haze days per year in Fuzhou. Both fog and haze days were variable, and there might be a day difference of twice to thrice among the years. They were the most in 2007, and then decreased in recent years. Both fog and haze days were more in winter and spring, accounted for 94.1% and 70.1% respectively, while in summer and autumn, they only accounted for 5.9% and 29.9% respectively. In a day, fog mainly occurred from night to early morning, while haze occurred mainly at about noon, which demonstrated that fog and haze are different synoptic phenomena. The mass concentration of PM2.5 in fog days was 34 μg/m^3, while it was 61 μg/m^3 in haze days, and in 22% of haze days it was larger than 75 μg/m3, which was above the national second-grade ambient air quality standard.展开更多
Based on data of number of fog and haze days in Baoji City from 1981 to 2013,the changing trends and mutation of number of fog and haze days in Baoji over the past 33 years were analyzed by using trend coefficient,ten...Based on data of number of fog and haze days in Baoji City from 1981 to 2013,the changing trends and mutation of number of fog and haze days in Baoji over the past 33 years were analyzed by using trend coefficient,tendency rate,linear regression analysis,anomaly percentage,Mann-Kendall mutation test and sliding t test.The results showed that during the 33 years,the number of fog and haze days in Baoji declined by 16.253d/10 a,and there was a cyclical turbulence every 6,15 or 28years.The frequency of fog and haze weather was the highest in winter,followed by spring and autumn,while it was the lowest in summer.According to the anomaly percentage of the number of fog and haze days in 12 months during 1981-2013,the anomaly percentage changed most greatly in July,followed by September,October,April,May,June,August,February and March,but it fluctuated less greatly in January.The number of fog and haze days from 1981 to 2013had obvious mutation trends in a single year and a single season,and mutation types are different.展开更多
基金Supported by the Key Project of Science and Technology Department of Fujian Province,China in 2012(2012Y0009)
文摘For data of atmospheric composition missing, fog and haze days were distinguished based on the standard of meteorological industry Observation and Forecasting Levels of Haze （QX/T113-2010） and four user-defined standards, and using data of surface meteorological factors in Fuzhou City, China from 2005 to 2011, temporal distributions of fog and haze days were analyzed respectively to provide methods for fog and haze forecast. The results showed that there were 28.9 fog days and 89.7 haze days per year in Fuzhou. Both fog and haze days were variable, and there might be a day difference of twice to thrice among the years. They were the most in 2007, and then decreased in recent years. Both fog and haze days were more in winter and spring, accounted for 94.1% and 70.1% respectively, while in summer and autumn, they only accounted for 5.9% and 29.9% respectively. In a day, fog mainly occurred from night to early morning, while haze occurred mainly at about noon, which demonstrated that fog and haze are different synoptic phenomena. The mass concentration of PM2.5 in fog days was 34 μg/m^3, while it was 61 μg/m^3 in haze days, and in 22% of haze days it was larger than 75 μg/m3, which was above the national second-grade ambient air quality standard.
基金Supported by the National Natural Science Foundation of China(41071359)
文摘Based on data of number of fog and haze days in Baoji City from 1981 to 2013,the changing trends and mutation of number of fog and haze days in Baoji over the past 33 years were analyzed by using trend coefficient,tendency rate,linear regression analysis,anomaly percentage,Mann-Kendall mutation test and sliding t test.The results showed that during the 33 years,the number of fog and haze days in Baoji declined by 16.253d/10 a,and there was a cyclical turbulence every 6,15 or 28years.The frequency of fog and haze weather was the highest in winter,followed by spring and autumn,while it was the lowest in summer.According to the anomaly percentage of the number of fog and haze days in 12 months during 1981-2013,the anomaly percentage changed most greatly in July,followed by September,October,April,May,June,August,February and March,but it fluctuated less greatly in January.The number of fog and haze days from 1981 to 2013had obvious mutation trends in a single year and a single season,and mutation types are different.
