基于精细观测资料的深圳不同季节霾及其污染特征分析

利用2010~2013年逐时霾、能见度和空气质量监测数据,分析了深圳霾天气的变化特征、霾与空气质量和气象条件的关系.结果表明:深圳市霾日数总体呈现增多增强趋势,2009年开始明显下降;霾日数呈“V”型月变化:即秋冬季多、春夏季少,秋冬季多发持续时间长、影响严重的霾过程,春夏季多发持续时间短的霾过程; 霾常伴有污染发生(35%),污染以轻度污染为主;霾时首要污染物PM2.5最多、其次O3,这说明PM2.5是造成深圳霾的主因,且深圳光化学污染严重. 霾时PM2.5、PM10 和O3季节变化明显,冬春季首要污染物以PM2.5为主(75%以上),夏秋季O3和PM2.5为主;分析还发现,风、相对湿度与霾密切相关,风速越弱,湿度越大, 越利于霾出现和发展.约80%的中重度霾出现在风速<2m/s,相对湿度70%~90%的情况下.

Seasonal characteristics and pollution of haze in Shenzhen based on meticulous observation data

Based on the Meticulous observational data of hourly haze, visibility and air quality monitoring of Shenzhen during 2010~2013, Seasonal variations of haze, the relationships of the meteorological conditions and air quality to haze were analyzed in order to provide the basis for issuing haze warning and forecast more pointedly. The results suggested that the annual haze days of Shenzhen presented an increasing trend overall and the phase change of a down trend since 2009. The monthly variations of haze days showed "V" type, which implied the haze occurred mainly in autumn and winter rather than in spring and summer. There were more long duration and serious haze processes in autumn and winter but short duration ones in spring and summer. The haze was often accompanied by mainly mild air pollution (35%). PM2.5 was the primary pollutant followed by O3, which indicated that PM2.5 was the main cause of haze weather and photochemical pollution was also serious in Shenzhen. There was significant variation of PM2.5, PM10 and O3 with the seasons. The primary pollutants changed with the seasons that PM2.5 was the main pollutant (above75%) in winter and spring, but O3 and PM2.5 were in summer and autumn. The wind and relative humidity were the important influencing factors of haze. The 80% of moderate and severe haze occurred under the wind speed <2m/s and relative humidity 70%~90% ,which suggested the weaker wind speed and the greater humidity were conductive to the emergence and development of haze.