贵阳市中心城区混合层高度变化特征与环境空气质量关系研究

Relationship between variation characteristics of mixing layer heights and air quality in urban Guiyang

根据2017年至2021年贵阳市中心城区的10个国控站点环境空气质量变化趋势,运用L波段雷达探空秒级数据,计算得出贵阳近5年混合层高度随时间序列变化特征,分析表明:(1)贵阳市四季混合层高度具有明显的季节变化,夏高冬低,日变化特征为07时至18时高,19时至06时低;(2)贵阳市混合层高度与污染天气的环境容量有直接相关性;(3)冬季大气以中性层结主导,低风速,混合层厚度低于200m是造成贵阳市主城区冬季轻度污染的主要因素。

Based on data from 10 national air quality control sites during the period from 2017 to 2021 and the calculation based on data from local radiosonde sounding system at the same period,a comparison was carried out concerning variation tendency of air quality and time series variation characteristics of mixing layer height in urban Guiyang.The results show that:(1)a significant seasonal variation of mixing layer height,high in summer and low in winter,while with daily variation characteristic of being high from 7 a.m.to 6p.m.and low from 7p.m.to 6 a.m.can be seen in Guiyang City;(2)a correlation exists between mixing layer heights and environmental buffering capacity during polluted period;(3)prevailing neutral layer,low wind speed,as well as the mixing layer height lower than 200m,could be the major reasons behind the slight air pollution in urban Guiyang during winter.