Scholarlink

This study investigates the impact of the COVID-19 lockdown on aerosol, particulate matter, and precursor gas characteristics over Panchgaon (Amity University Haryana), a rural station in Haryana State, India. We analyzed synchronous satellite data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Ozone Monitoring Instrument (OMI), alongside ground-based retrievals of columnar aerosol optical depth (AOD), total column ozone (TCO), precipitable water vapor (PWV), and surface-level PM1, PM2.5, PM10, and ozone (O3) mass concentration. The study period spans from February 01, 2020, to June 30, 2020, covering the pre-restriction, restriction, and post-restriction phases. To observe the effect of restriction, all these parameters of 2020 were compared to those of the last year, 2019 (free from restriction). Our findings revealed a significant reduction (up to 50%) in daily mean AOD values retrieved from MODIS during the first phase of restriction. The results also show an overall decreasing trend in AOD values during the restriction phases compared to the pre-restriction period. In contrast, TCO exhibited a slight decline of 13–16 Dobson unit (DU) during the final phase of the restriction and post-restriction period. An increase in the concentration of precursor gases (O3 and PWV) during the second phase (15/04/2020 to 03/05/2020) of restriction was observed. The concentration of particulate matters also showed a significant decrease, with reductions of 50% to 60% during the first three phases of restriction. Thus, the influence of COVID-19 restrictions demonstrated a reduction in anthropogenic activities during the various phases of the 2020 lockdown compared to the unrestricted period in 2019. Additionally, the potential sources and transport pathways of the measured air pollutants were characterized through concentration-weighted trajectory (CWT) analysis across the various phases of the restrictions. In all the respective restriction phases, major PM 2.5 contribution is from local and slow-moving air mass trajectories, except in III phase (May 4, 2019, to May 17, 2019), when the major contribution is from distant and fast-moving trajectories.

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

Changes in Near-Surface and Columnar Aerosol Loading Over a Rural Site During COVID-19 Pandemic

  • 章节

  • 发表日期：

    2025年

查看全文
  • Abul Amir Khan,
  • Panuganti C. S. Devara,
  • Atul K. Srivastava,
  • Bandaru S. Murthy

摘要

This study investigates the impact of the COVID-19 lockdown on aerosol, particulate matter, and precursor gas characteristics over Panchgaon (Amity University Haryana), a rural station in Haryana State, India. We analyzed synchronous satellite data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Ozone Monitoring Instrument (OMI), alongside ground-based retrievals of columnar aerosol optical depth (AOD), total column ozone (TCO), precipitable water vapor (PWV), and surface-level PM1, PM2.5, PM10, and ozone (O3) mass concentration. The study period spans from February 01, 2020, to June 30, 2020, covering the pre-restriction, restriction, and post-restriction phases. To observe the effect of restriction, all these parameters of 2020 were compared to those of the last year, 2019 (free from restriction). Our findings revealed a significant reduction (up to 50%) in daily mean AOD values retrieved from MODIS during the first phase of restriction. The results also show an overall decreasing trend in AOD values during the restriction phases compared to the pre-restriction period. In contrast, TCO exhibited a slight decline of 13–16 Dobson unit (DU) during the final phase of the restriction and post-restriction period. An increase in the concentration of precursor gases (O3 and PWV) during the second phase (15/04/2020 to 03/05/2020) of restriction was observed. The concentration of particulate matters also showed a significant decrease, with reductions of 50% to 60% during the first three phases of restriction. Thus, the influence of COVID-19 restrictions demonstrated a reduction in anthropogenic activities during the various phases of the 2020 lockdown compared to the unrestricted period in 2019. Additionally, the potential sources and transport pathways of the measured air pollutants were characterized through concentration-weighted trajectory (CWT) analysis across the various phases of the restrictions. In all the respective restriction phases, major PM 2.5 contribution is from local and slow-moving air mass trajectories, except in III phase (May 4, 2019, to May 17, 2019), when the major contribution is from distant and fast-moving trajectories.