| 摘要: |
| 基于中国中东部地区2014—2019年秋、冬季（11月—次年2月）、暖季（4—10月）的细颗粒物（PM2.5 ）、臭氧（O3 ）监测数据，运用T-mode斜交旋转主成分分析法（T-mode PCA）对长三角及周边地区2014—2019年925hPa位势高度和风场进行大样本客观分型，总结了有利于和不利于长三角地区PM2.5 和O3 污染发生的大气环流类型。结果表明，17类大气环流类型会影响长三角地区空气质量，并进一步识别出PM2.5 污染和O3 污染易发的大气环流型。其中，秋、冬季PM2.5 污染易发的环流型是冷锋相关（AW_CT2）和出海高压（AW_CT3和AW_CT5）相关，前者可能与上风向PM2.5 污染输送相关，后者则可能以局地累积和转化过程为主。副高控制（Spring_CT1和Summer_CT1）和均压场（Summer_CT3和Autumn_CT2）环流型则有利于促发暖季O3污染；在Spring_CT1、Summer_CT1、Summer_CT3和Autumn_CT2环流型下，长三角5个重点城市O3 超标率和ρ（O3 -8h）水平高于同季节的其他环流类型，但气象和化学影响机制可能有所差异。此外，副高控制和均压场环流型也易导致上海、杭州和南京等城市出现暖季PM2.5 和O3 双高污染。 |
| 关键词: 大气环流型 细颗粒物 臭氧 双高污染 长三角地区 |
| DOI：DOI：10.3969/j.issn.1674-6732.2024.04.006 |
| 分类号:X51 |
| 基金项目:中央引导地方科技发展资金项目（2022ZYD0129） |
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| Pollution Characteristics of PM2.5 and O3 under Atmospheric Circulation Types in the Yangtze River Delta Region during 2014—2019 |
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YAN Yu1,2， SHI Wenbin3， WANG Cong1,2， CHEN Youfan1,2
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1.Sichuan Academy of Environmental Policy and Planning， Chengdu， Sichuan 610041， China；
2.Tianfu Yongxing Laboratory， Chengdu， Sichuan 610217， China；
3.Wuxi Ninecosmos Science and Technology， Wuxi， Jiangsu 214000， China
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| Abstract: |
| Based on the PM2.5 and O3 monitoring data and NCEP-FNL data（i.e geopotential height and u、v wind at 925 hPa） in the fall and winter（i.e.， January， February， November， and December） and the warm season（i.e.，April-October） in the central eastern region of China from 2014 to 2019， typical atmospheric circulation types（CTs） were recognized via T mode PCA classification method. The results showed that during the research period， seventeen CTs affected air quality in the Yangtze River Delta region （YRD region）， and the CTs that were prone to the occurrence of PM2.5 and O3 pollution were furtherly identified. High PM2.5 concentration in autumn and winter（i.e.， January， February， November， and December） were usually related to cold front（AW_CT2） and High Pressure Moving to Sea（AW_CT3 and AW_CT5） weather system. Atmospheric circulation conditions may be conductive for upstream pollutant transport for AW_CT2 and local accumulation for AW_CT3 and AW_CT5 respectively. While high ozone concentration in warm season（i.e.， from April to October） were associated to subtropical high control（Spring_CT1 and Summer_CT1） and uniform pressure field（Summer_CT3 and Autumn_CT2）， but there may be differences in the impacts of meteorological characteristics and photochemical processes for O3 pollution. The O3 polluted days and MDA8 O3 concentrations in the five cities of the YRD region were higher than those controlled by other CTs in the same seasons. Moreover， double high pollution was frequently occurred in Shanghai， Hangzhou and Nanjing under subtropical high control and uniform pressure field. |
| Key words: Atmospheric circulation type PM2.5 Ozone Double high pollution Yangtze River Delta |
