CAJ | 학술논문

利用 PM2.5、PM10、O 3、NO 2、CO 5种大气成分浓度数据、常规气象观测数据和 NCEP 再分析资料,结合HYSPLIT4后向轨迹模式,对2013年12月1—9日发生在上海市的一次大面积、长时间重霾污染天气过程,从大气成分浓度变化、天气形势特征及成因机制等方面进行了综合分析.研究表明,此次重霾污染期间的日空气质量指数(air quality indexs,AQI)均超过150的中度污染限值,水平能见度最低降至100 m 以下,首要污染物 PM2.5最高小时浓度达到602.3μg·m-3,创造了上海市有 PM2.5监测记录以来的历史峰值.本次过程具有较强的区域性,是一次大范围的重霾天气过程,受气象条件这一扩散大背景影响很大.相比于近十年的气象场平均态而言,此次污染时段内的高空场更不利于上升运动的发展,更加静稳的地面高压场分布为重霾污染天气的发生、发展提供了有利的气象条件,近地面稳定的大气层结和静小风,非常不利于污染物的扩散.研究还表明该污染事件与大范围秸秆集中燃烧,造成大量污染物排放有一定关系.通过后向轨迹计算分析,发现颗粒物长距离输送对区域污染产生重要影响.
이용 PM2.5、PM10、O 3、NO 2、CO 5충대기성분농도수거、상규기상관측수거화 NCEP 재분석자료,결합HYSPLIT4후향궤적모식,대2013년12월1—9일발생재상해시적일차대면적、장시간중매오염천기과정,종대기성분농도변화、천기형세특정급성인궤제등방면진행료종합분석.연구표명,차차중매오염기간적일공기질량지수(air quality indexs,AQI)균초과150적중도오염한치,수평능견도최저강지100 m 이하,수요오염물 PM2.5최고소시농도체도602.3μg·m-3,창조료상해시유 PM2.5감측기록이래적역사봉치.본차과정구유교강적구역성,시일차대범위적중매천기과정,수기상조건저일확산대배경영향흔대.상비우근십년적기상장평균태이언,차차오염시단내적고공장경불리우상승운동적발전,경가정은적지면고압장분포위중매오염천기적발생、발전제공료유리적기상조건,근지면은정적대기층결화정소풍,비상불리우오염물적확산.연구환표명해오염사건여대범위갈간집중연소,조성대량오염물배방유일정관계.통과후향궤적계산분석,발현과립물장거리수송대구역오염산생중요영향.
A heavy haze episode from 1 st to 9 th in December 2013 in Shanghai was analyzed.In this paper we reported a research of exploring the pollution characteristic and the mechanism of the haze event with emphasizing the concen-trations variation of polluting components,the synoptic condition and the source of the heavy haze event.The AQIs (air quality indexs)during this haze period were all above 1 50 and the highest hourly PM2.5 concentration was 602.3μg·m-3 ,creating a new record in Shanghai,and the visibility was less than 100 m during this period.Shanghai Central Meteorological Observatory issued a haze orange waining signal on 7:22 of the December 2 nd ,and this is the first time in Shanghai issued a haze orange signal warning.The results show that the formation of heavy haze event was directly related to the atmospheric condition.Steady circumfluence of the atmosphere made the haze event last a long time in a large region.On the other hand,there was a weak high pressure at the surface in the area of Shanghai, therefore the atmospheric current flowed downward the area to make the upward diffusion of pollutants and turbulence was restrained.We also analysis the mean height at 500 hPa,mean sea level pressure field and sea level wind field of 1 st to 9 th of 1 994—2013.The result shows that comparing with the 10 years average state,the pressure field during the haze episold is obviously weaker,the air pressure is lower,the pressure gradient is smaller and all these lead to a smaller ground wind speed.is not conducive to the level of pollutant diffusion.Therefore,the pollutants could not diffuse horizontally quickly.In addition,the Hysplit4 trajectory model indicated that the source of the pollutants in Shanghai was from Hubei,Jiangsu and Anhui provinces,and at the same time,the MODIS instrument aboard the Terra and Aqua satellites observed many fire dots in these areas before the haze.Therefore, and the burning of straw in east China could be one reason for the heavy haze episode.