Then and Now: COVID-19 Pandemic Lockdown Misfire Atmospheric Methane over India

Manoj Hari ； Rajesh Kumar Sahu ； MS Shyam Sunder ； Bhishma Tyagi

《Aerosol and Air Quality Research》 22卷4期 (2022/04) Pp. 1-10+ap1-5-003

https://doi.org/10.4209/aaqr.210354

摘要

COVID-19 lockdown resulted in the revival of the environment due to reduced emissions of various pollutants globally. In particular, aerosols, NO_x and SO_2 showed significant reductions at most places. However, the greenhouse gases are not necessarily following this reduction everywhere. In most areas, a decrease in NO_x increases methane (CH_4) concentration by enhancing the lifetime, but also results in decreased concentrations with reduced emissions. Analyzing the atmospheric CH_4 variations during the COVID-19 lockdown over India is crucial as India is one of the regions with high seasonal variability of CH_4. The present study has analyzed the tropospheric CH_4 trends over India during the pre-monsoon season (March-May) for 2003-2021 using AIRS data. The study analyzed the lockdown variations (24 March-31 May) of tropospheric CH_4 over India with the same period of 2019 and 2021 using TROPOMI to find the changes in CH_4 concentrations over different regions of India due to lockdown. Our results capture the undeviating north (low)-south (high) gradient in the CH_4 concentration with anticipated regional intensifications, likely, in the eastern and western coastal regions, with more comprehensive details than it ever has been presented before.

關鍵字

Atmospheric methane ； NO_x ； COVID-19 lockdown ； Seasonal variability ； TROPOMI