Scholarlink

<p>Ozone (O<sub>3</sub>) in ambient air acts as a greenhouse gas and has harmful effects on human health and vegetation. Short-term exposure to elevated surface O<sub>3</sub> is linked to increased risks of respiratory and cardiovascular mortality. The emission of volatile organic compounds (VOCs) and nitrogen oxides (NO<sub>x</sub>) into the atmosphere can trigger chemical reactions influenced by solar radiation (SR), resulting in O<sub>3</sub> formation in the troposphere. This study focuses on a few locations within Delhi and Mumbai using publicly available data. O<sub>3</sub> concentrations peak in the afternoon and decrease subsequently. During winter, NO<sub>x</sub> concentrations were higher, while O<sub>3</sub> concentrations were lower, possibly due to reduced solar radiation and altered atmospheric VOC-NO<sub>x</sub> regimes. The HCHO/NO<sub>2</sub> ratios in both Delhi and Mumbai are less than 1, indicating VOC-limited conditions. The secondary fraction (SA) of PM<sub>2.5</sub> at select locations was estimated using the Approximate Envelope Method (AEM). SA values derived from AEM exhibited diurnal trends consistent with field studies and established knowledge. This analysis demonstrated that SA can constitute up to 85% of total PM<sub>2.5</sub>, highlighting its significant contribution to overall particulate matter levels. An evaluation of the AVOC-NOx-O<sub>3</sub>-SA relationship revealed that elevated O<sub>3</sub> concentrations predominantly occur at higher AVOC/NOx ratios, often leading to increased SA levels to some extent. To predict O<sub>3</sub>, a multiple linear regression model was employed, incorporating various parameters. The model achieved a coefficient of correlation when compared to measured data of over 0.90, indicating its effectiveness in predicting O<sub>3</sub> levels. This research provides valuable insights into the dynamics of surface O<sub>3</sub> and its implications for urban secondary pollutants.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Evaluating urban ozone dynamics in two Indian megacities using ground data and predictive ozone modelling: role of AVOC – NOx regime and influence on secondary PM levels

  • 期刊论文

  • 发表日期：

    2025年3月25日

查看全文
  • Yuva Kiran Kadali,
  • Abhishek Chakraborty

摘要

Ozone (O3) in ambient air acts as a greenhouse gas and has harmful effects on human health and vegetation. Short-term exposure to elevated surface O3 is linked to increased risks of respiratory and cardiovascular mortality. The emission of volatile organic compounds (VOCs) and nitrogen oxides (NOx) into the atmosphere can trigger chemical reactions influenced by solar radiation (SR), resulting in O3 formation in the troposphere. This study focuses on a few locations within Delhi and Mumbai using publicly available data. O3 concentrations peak in the afternoon and decrease subsequently. During winter, NOx concentrations were higher, while O3 concentrations were lower, possibly due to reduced solar radiation and altered atmospheric VOC-NOx regimes. The HCHO/NO2 ratios in both Delhi and Mumbai are less than 1, indicating VOC-limited conditions. The secondary fraction (SA) of PM2.5 at select locations was estimated using the Approximate Envelope Method (AEM). SA values derived from AEM exhibited diurnal trends consistent with field studies and established knowledge. This analysis demonstrated that SA can constitute up to 85% of total PM2.5, highlighting its significant contribution to overall particulate matter levels. An evaluation of the AVOC-NOx-O3-SA relationship revealed that elevated O3 concentrations predominantly occur at higher AVOC/NOx ratios, often leading to increased SA levels to some extent. To predict O3, a multiple linear regression model was employed, incorporating various parameters. The model achieved a coefficient of correlation when compared to measured data of over 0.90, indicating its effectiveness in predicting O3 levels. This research provides valuable insights into the dynamics of surface O3 and its implications for urban secondary pollutants.