成都平原经济区秋冬季大气自净能力研究

Study on the Atmospheric Self-purification Capacity of Chengdu Plain Economic Zone in Autumn and Winter

基于2014~2018年秋冬季(11月、12月、次年1月、2月)一日4次(02、08、14和20时)的地面气象观测资料,利用大气自净能力指数ASI的计算方法对成都平原经济区(成都、德阳、绵阳、眉山、乐山、资阳、遂宁、雅安)秋冬季大气自净能力及其影响因子进行了分析研究。结果表明:(1)从时间变化而言,一日之中大气自净能力夜晚值最小,午间值最大;月变化来看12月大气自净能力最弱,2月最强。(2)从空间变化而言,成都平原经济区大气自净能力的空间变化整体表现为西南低东北高的走势,绵阳大气自净能力最强,乐山、雅安、眉山地区大气自净能力较差;(3)混合层高度和风速与大气自净能力指数的相关性较强,由于秋冬季降水稀少,因此其对秋冬季成都平原经济区的影响甚微;(4)成都平原经济区各城市的大气自净能力指数与AQI指数都具有显著的幂指数的反相关关系。

Based on the surface meteorological observation data during autumn and winter(November,December,January and February of the next year)four times a day(02,08,14 and 20 o’clock)from 2014 to 2018,this paper studied the characteristics of Atmosphericself purification capacity of Chengdu Plain Economic Zone(Chengdu,Deyang,Mianyang,Meishan,Leshan,Ziyang,Suining,Ya’an)in autumn and winter and its influencing factors were analyzed by using ASI..The results showed that:1)in terms of time change,the atmospheric self-purification capacity is the lowest at night and the highest at noon in one day;in terms of monthly change,the atmospheric self-purification capacity is the weakest in December and the strongest in February.2)From the perspective of spatial change,the overall spatial change of air self purification capacity in Chengdu Plain Economic Zone shows a trend of low in the southwest and high in the northeast.Mianyang has the strongest air self purification capacity,while Leshan,Ya’an and Meishan areas have poor air self purification capacity.3)The height and wind speed of the mixed layer have a strong correlation with air self purification capacity index.Due to the lack of precipitation in autumn and winter,it has little impact on Chengdu Plain Economic Zone in autumn and winter 4)There is a significant inverse correlation between the air self-purification capacity index and AQI index of each city in Chengdu Plain Economic Zone.