苏皖鲁豫典型区域臭氧垂直结构及其影响因素分析

Vertical Structure of Ozone and Its Influencing Factors in the Border Area of Jiangsu,Anhui,Shandong and Henan Provinces

苏皖鲁豫交界地区已成为全国大气污染防治的重点关注区域之一.为探究苏皖鲁豫区域臭氧垂直结构特征及气象因素与潜在来源的影响,利用激光雷达对淮北市2021年11月臭氧和气象垂直结构进行观测.结果表明:(1)淮北市地面臭氧浓度呈单峰日变化特征,2021年11月16—18日出现了持续3 d的高空臭氧污染.在清洁日(高空臭氧小时浓度<200μg/m^(3)),1.5 km以下臭氧浓度随高度的增加呈先升后降的趋势;在污染日(高空臭氧小时浓度≥200μg/m^(3)),2021年11月16日和17日臭氧为双层分布,18日臭氧浓度在1.5 km以下随高度的增加而下降.(2)在垂直高度上,污染日的温度高于清洁日,风速低于清洁日,即高温低风有利于高空臭氧污染产生,16日逆温层对臭氧浓度的积累有重要作用,风向转变和下沉气流也是造成污染日高空臭氧聚集的重要原因.(3)臭氧潜在来源及贡献分析显示,观测日(整个观测期,2021年11月10—19日)的高臭氧浓度可能与淮北市本地生成及其南部、东部的区域输送有关,清洁日的臭氧浓度主要受河南省的影响,污染日的高空臭氧污染不仅与本地生成有关还与周边城市的臭氧及臭氧前体物输送有关.研究显示,温度、风速、风向以及区域输送对淮北市臭氧浓度的垂直结构演变有显著影响.

The border area of Jiangsu,Anhui,Shandong and Henan has become one of the key areas for national air pollution prevention and control in China.The aim of this study is to investigate the vertical structure characteristics of ozone,the influence of meteorological factors and potential sources in Jiangsu,Anhui,Shandong and Henan regions.The vertical structures of ozone and meteorology in Huaibei City in November 2021 were observed by lidar.The results showed that:(1)The surface ozone concentration was characterized by singlepeak daily variation,and there was a continuous three-day high-altitude ozone pollution from November 16^(th) to 18^(th),2021.On the clean days(defined as the hourly high-altitude ozone concentration<200μg/m^(3)),the ozone concentration below 1.5 km increased first and then decreased with the increase of altitude.On polluted days(defined as the hourly high-altitude ozone concentration≥200μg/m^(3)),the ozone distribution appeared as double layers on November 16^(th) and 17^(th),2021 and the ozone concentration decreased with the increasing altitude below 1.5 km on the November 18^(th).(2)At vertical altitude,the temperature on the polluted days was higher than that on the clean days,and the wind speed was lower than that on the clean days,indicating that high temperature and low wind were conducive to the generation of high-altitude ozone pollution.The inversion layer on the November 16th played an important role in the accumulation of ozone concentration,and the changes in wind direction and downdraft were also the important causes of ozone accumulation in the upper air on the polluted days.(3)The analysis of potential ozone sources and their contributions showed that the high ozone concentration on the observation days(defined as the entire observation period:November 10^(th)-19^(th),2021)may be related to the local generation of Huaibei City and regional transport in the south and east of Huaibei City.The ozone concentration on the clean days was mainly affected by Henan Province.The high-altitude ozone pollution on the polluted days was related to the local generation and the transport of ozone and its precursors in surrounding cities.Based on the above research results,temperature,wind speed,wind direction and regional transport had significant effects on the evolution of the vertical structure of ozone concentration in Huaibei City.