| 北京市冬季雾霾天人体呼吸高度PM2.5变化特征对气象因素的响应 |
| 摘要点击 2918 全文点击 1086 投稿时间：2015-09-07 修订日期：2016-02-25 |
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| 中文关键词 北京 人体呼吸高度 PM2.5 污染天 气象因素 |
| 英文关键词 Beijing human respiratory height PM2.5 polluted days meteorological factors |
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| 中文摘要 |
| 依据实测北京冬季人体呼吸高度PM2.5质量浓度、湿度、风速、风向、温度数据,利用相关性分析、非线性回归分析、统计分析,分别探讨轻中度空气污染天、一次重污染过程,气象因子对PM2.5质量浓度生成、变化的影响.结果表明:①轻中度污染天,若温度较低、日平均风速较小,湿度大时,湿度是影响PM2.5质量浓度变化的决定性因素;而温度、风速、湿度均较大时,PM2.5质量浓度变化受三者共同作用;当风速、湿度、温度均较小时, PM2.5质量浓度变化主要受前两者影响.这反映出,人体呼吸高度的PM2.5质量浓度变化对气象因子微小变化响应极为敏感.②一次空气质量从良到重度污染的过程中,PM2.5质量浓度积累主要是由于空气湍流较弱、加之湿度大导致的,此外白天西北风、东北风较大,但持续时间短,而夜间东南风、西南风风速较小,持续时间长,也有利于污染物的累积.③短时微小量降雪使温度降低、空气湿度增加,不仅不能降低PM2.5质量浓度,反而使其上升了72%,造成颗粒物浓度的跃升现象.④短时风速较大,风速达到2.0m·s-1,持续2 h,虽然在一定程度上降低局地PM2.5质量浓度,但并不能彻底改变空气质量状况.只有当风速大于3.5 m·s-1,且持续4 h以上,才能够迅速地扩散空气中的细颗粒物,空气质量由重度污染转变为优. |
| 英文摘要 |
| In order to investigate the influence of meteorological factors on the variation characteristics of PM2.5 in Beijing. According to the survey of PM2.5 mass concentration in height of human respiration, humidity, the direction of the wind, wind speed and temperature. Using the methods of correlation analysis and nonlinear regression analysis, the effects of meteorological factors on the formation and variation of PM2.5 mass concentration in light and moderate air pollution days and heavy pollution were discussed respectively. The results showed that:① On mild to moderate pollution days, if the temperature was low, the daily average wind speed was low, the humidity was high, then the humidity was the decisive influencing factor of PM2.5 mass concentration; if the temperature, wind speed and humidity were all high, then the variation of PM2.5 mass concentration was influenced by the combined action of these three; when the temperature, humidity and wind speed were all low, then the PM2.5 mass concentration was mainly affected by the first two factors. This suggested that changes in the height of the human respiration PM2.5 mass concentrations were extremely sensitive to small changes in meteorological factors; ② During the process of air quality turning from good to heavily polluted, the accumulation of PM2.5 mass concentration was mainly due to the weak air turbulence, coupled with the high humidity, in addition, the northwest wind and northeast wind were larger during the daytime but the duration was shorter, while the southeast and southwest wind speed at night was lower with longer duration, which was conducive to pollutant accumulation;③ Short-term low amount of snow decreased the temperature and increased the air humidity, which not only could not reduce the PM2.5 mass concentration, but rather increased it by 72%, resulting in the jump phenomenon of particle concentration; ④ When the wind speed reached up to 2.0 m·s-1 and lasted for two hours, the local PM2.5 mass concentrations could be reduced to some extent, but it could not completely change the air quality situation. Only when the wind speed was greater than 3.5 m·s-1 and lasted for more than 4 hours, the fine particulate matter in the air could be quickly diffused and the air quality was changed from heavy pollution to excellent. |
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