广东秋季臭氧污染过程敏感性分析

Sensitivity Analysis of Ozone Pollution Process in Autumn in Guangdong

使用三维空气质量模型WRF/CAMx及化学过程分析工具,通过过氧化氢与硝酸生成速率比值(P_(H_(2)O_(2))/P_(HNO_(3)))与自由基反应链长(HOx_CL)定量研究了珠三角中西部代表性点位臭氧生成敏感性。2018年国庆前后,珠三角中西部的臭氧污染事件中,P_(H_(2)O_(2))/P_(HNO_(3))与HOx_CL具有较好的反相关关系,不论城市还是郊区,随着高度的上升,HOx_CL会有所下降,城市地区的近地面为臭氧生成的VOCs敏感区外,百米以上高空的臭氧生成敏感性均以NOX敏感为主。在近地面,除广州与江门市区是臭氧生成的VOCs敏感区外,其余大部分地区的臭氧生成敏感性均以NOX敏感为主。本次污染事件中,珠三角中西部大部分臭氧仍主要在NOX敏感区中生成,若要减轻珠三角秋季区域臭氧污染,建议珠三角所有地区加大NOX减排,城市市区增强VOCs减排。

Using three-dimensional air quality model WRF/CAMX and chemical process analysis tools,the sensitivity of ozone generation at representative sites in the central and Western Pearl River Delta was quantitatively studied by ratio of formation rate of hydrogen peroxide to nitric acid(P_(H_(2)O_(2))/P_(HNO_(3)))and HOx chain length(HOx_CL).Before and after the National Day of 2018,the ozone pollution events happened in the central and Western Pearl River Delta.Its P_(H_(2)O_(2))/P_(HNO_(3)) and HOx_CL had a good inverse correlation.Whether in cities or suburbs,with the rise of height,HOx_CL would decrease.The ozone formation regime in the urban near ground areas was VOCs sensitive,and it was mainly NOX sensitive above 100m.In the near ground area,the ozone formation regime in Guangzhou and Jiangmen was VOCs-sensitive,and it was NOX-sensitive in most of the other areas.In this pollution event,most of the ozone in the central and Western Pearl River Delta was mainly generated in the NOX-sensitive situation.In order to reduce the regional ozone pollution in the Pearl River Delta in autumn,it was suggested that all regions of the Pearl River Delta should reduce NOX emission.