| 摘要: |
| 工业和交通废气、农业和生活烟雾等污染物排放是城市雾霾的重要来源,其污染物特别是细颗粒物质对人体健康有损害。就区域而言,我国北方的污染物PM2.5、PM10、CO、SO2的浓度较高,中西部、东南部和南部较低;中国大部分地区的季节性高污染通常出现在冬季。其原因主要是因为细颗粒物排放量大,且受不利气象条件的影响,停滞的气流不利于气溶胶扩散。夜间PM2.5的浓度通常高于白天,其原因:一是由于重型车辆通常在夜间作业,而且烧烤、非法秸秆焚烧等活动一般在夜间进行,导致夜间的污染物排放量增加;二是由于夜间地面温度低,空气湍流减少而导致垂直空气运动很少,故气流停滞现象夜间尤为明显。历史上喀麦隆尼奥斯湖和印度博帕尔灾难的加剧也是由于此类气象条件所致。本研究提出夜间废气排放加重了中国雾霾污染的设想,并通过分析北京地区54511气象观测站提供的2014年每天、每小时的地面气温数据,发现减少夜间污染排放可能是现阶段减少雾霾形成的低成本措施之一。 |
| 关键词: 污染排放 雾霾 PM2.5 逆温 减排 |
| DOI： |
| 投稿时间：2015-12-10修订日期：2015-12-20 |
| 基金项目:国家自然科学基金项目(31560315)和广西人才小高地建设专项基金资助。 |
|
| Increase in Haze Pollutions in China due to Nocturnal Emissions |
|
YAN Shao-min, WU Guang
|
| (Guangxi Bioscience and Biotechnology Research Center, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, China) |
| Abstract: |
| Emissions from traffic, industrial combustion, heating and biomass burning are important sources for the formation of haze, of which fine particulate matter is particularly harmful to human health.Regionally, PM2.5, PM10, CO and SO2 concentrations are generally higher in northern China than in western, southeast and southern China because of large PM emissions and unfavorable meteorological conditions for pollution dispersion.Seasonally high pollutions are often visible in winter in most parts of China.Daily, PM2.5 is frequently higher during nighttime than during daytime.The increase in PM2.5 in nighttime can be attributed to heavy vehicles such as diesel trucks, evening recreation activities such as barbecues, and illegal rubbish burning.Of various factors promoting the formation of haze, stagnant airflow is very important because it makes the dispersal of aerosols difficult.This is crucial for the nighttime because the ground temperature decreases during the nighttime and air turbulence decreases leading to very little vertical air motion.Such meteorological conditions had led to Lake Nyos and Bhopal disasters in history.In this study, we hypothesized that nocturnal emissions increase the haze pollutions in China, and analyzed the meteorological data on hourly surface temperature from Beijing 54511 Observation Station in 2014.The results show that the surface temperature was lower at nighttime than at daytime.Therefore, reduction of emission at nighttime could be a cost-effective way to lessen haze pollution at the present stage. |
| Key words: pollution emissions haze PM2.5 inverse temperature emission reduction |
