1999—2019年南昌市大气能见度变化特征分析

Distributional Characteristics of Visibility and its Affecting Factors in Nanchang from 1999 to 2019

利用1999—2019年南昌市国家基本气象站大气能见度和地面气象要素的观测资料和2016—2019年主要污染物浓度数据,分析了南昌市大气能见度的时间变化规律和影响因子。结果表明:(1)南昌市21年来大气能见度年平均为10.62 km,年际变化率2.12 km/10年,2017年增速最快;夏季能见度增速最明显,冬季年际变化不大。能见度日变化明显,平均在08:00最低,17:00最高。在月、季尺度上,夏季能见度最好,7月大气能见度最高;冬季最差,1月大气能见度最低。(2)南昌市大气能见度1999—2019年的年均值和四季均值都发生了明显突变,并且2017年均出现了1次突变,这与政府部门打响“蓝天保卫战”,大力开展大气污染防治工作的开始时间基本对应。

This paper analyze and study the time change law and influencing factors of atmospheric visibility in Nanchang,using the observation data of atmospheric visibility and ground meteorological elements from the national basic weather station of Nanchang from 1999 to 2019 and the main pollutant concentration data from 2016 to 2019.Results show that:(1)The annual average visibility of Nanchang City was 10.62 km from 1999 to 2019,and the inter-annual change rate was 2.12 km/10 a,with the fastest growth rate in 2017.The growth rate of visibility was the most obvious in summer,and the interannual change in winter was not strong.Visibility varies significantly daily,with the lowest average at 08:00 and the highest at 17:00.On the monthly and seasonal scales,the visibility was the best in summer,with the highest in July;the worst in winter,with the lowest in January.(2)The annual average and the four-season average of Nanchang’s atmospheric visibility from 1999 to 2019 have undergone significant abrupt changes,and there has been a sudden abrupt change in 2017.This was also the beginning of the government’s launch of the“Blue Sky Defense”and vigorous efforts to prevent and control air pollution.