大气科学2025，Vol.49Issue(6)：1663-1674,12.DOI:10.3878/j.issn.1006-9895.2412.24005
中国西部荒漠城市高背景臭氧浓度受局地弱人为影响的特征
Characteristics of Weak Anthropogenic Influences on High Background Ozone Concentrations in the Desert Cities of Western China
摘要
Abstract
There are large gaps in the domestic and international research on the characteristics of ozone(O3)concentration evolution in desert areas.Alxa Left Banner is a typical desert city in western China;it has high background O3 concentrations because of the low intensity of anthropogenic activities.From 2015 to 2022,the annual growth of daily maximum 8-h average ozone(MDA8 O3)was approximately 2 μg m-3.The average MDA8 O3 values in spring,summer,autumn,and winter were 111.3 μg m-3,132.3 μg m-3,101.8 μg m-3,and 82.9 μg m-3,respectively.The existence of favorable conditions,namely,high temperature and strong radiation,promotes the atmospheric photochemical reaction of O3 and enhances the secondary production of O3;therefore,O3 pollution incidents mainly occur in the summer.The O3 concentrations in Alashan Left Banner were 93-106 μg m-3 on summer nights under the influence of the NO titration effect,indicating that this region featured a high background O3 level.The greater the distance from the observation point to the ground,the higher the O3 concentration.The observations showed that the near-surface anthropogenic emissions have a direct and significant influence on the vertical O3 concentrations at three stations(Huanbaojuxinlou,Mengeryou,and Xihuayuan stations)with different heights over the ground surface.The O3 concentration at Huanbaojuxinlou station(22 m above the ground)was set as a criterion.The O3 concentration at Mengeryou station,15 m above the ground,was lower by 5-25 μg m-3 during the night and higher by 5 μg m-3 at noon.The O3 concentration at Xihuayuan station,12 m above the ground,was lower by 10-25 μg m-3 during the night and higher by 5 μg m-3 at noon.A strong NO titration effect was observed in the near-ground atmosphere in the urban areas at night.However,high O3 concentrations were observed in the near-ground atmosphere because of convective diffusion and rapid photochemical reactions.Thus,the weak effect of human activities on O3 concentration was illustrated,and the vertical distribution characteristics of O3 in desert cities were captured.关键词
臭氧污染/滴定效应/光化学过程/西部荒漠/阿拉善左旗Key words
Ozone pollution/Titration effect/Photochemical processes/Western desert/Alxa Left Banner分类
天文与地球科学引用本文复制引用
张少亭,田永莉,辛金元,吴八一,王芳,武红,任鑫冰,马永敬,吴方堃,孙扬,周兴军..中国西部荒漠城市高背景臭氧浓度受局地弱人为影响的特征[J].大气科学,2025,49(6):1663-1674,12.基金项目
国家重点研发计划项目2022YFF0802501,内蒙古自治区科技计划项目2021GG0100 National Key Research and Development Program of China(Grant 2022YFF0802501),Science and Technology Program of Inner Mongolia Autonomous Region(Grant 2021GG0100) （Grant 2022YFF0802501）
