Himalaya Air Quality Impacts From the COVID‐19 Lockdown Across the Indo‐Gangetic Plain

Abstract

 The COVID-19 lockdown provides an opportunity to the assess the impact of air pollution from the Indo-Gangetic Plain on the Himalaya.  Air pollutions levels in cities in the western Indo-Gangetic Plain experienced marked drops that coincided with the lockdown.  Across the Indo-Gangetic Plain and Himalaya, there were reductions in air pollution in the west and increases in the east.

Comparing the Change in Air Quality during the COVID-19 Lockdown between Dry and Wet Seasons in Nepal

“…There are a number of assessments conducted on a national, regional, or global scale investigating the association between the COVID-19 lockdown and air quality (Dasgupta and Srikanth, 2020;Madineni et al, 2021;Moore and Semple, 2021;Nigam et al, 2021;Pozzer et al, 2020;Prakash et al, 2021;Sannigrahi et al, 2021;Tang et al, 2021;Upadhyay et al, 2022). Those studies have shown a mix of findings with marked spatial heterogeneity in the change in air quality parameters during the lockdown period compared to the baselines.…”

“…In Nepal, a countrywide lockdown was imposed from 24 March to 20 July to contain the spread of the SARS-CoV-2 virus during the first wave of the COVID-19 pandemic. The air quality change during lockdowns are not geographically uniform and are determined by a mix of factors, such as major air pollutant sources, and the meteorology and topography of a region (Gao et al, 2021;Moore and Semple, 2021;Tang et al, 2021;Upadhyay et al, 2022). A recent study analyzed the change in air quality over the South Asia region, where Nepal is located, during a narrow window (25 March-30 April 2020; dry season) of the lockdown period (Upadhyay et al, 2022).…”