TCS Research and Innovation, Tata Consultancy Services, Yantrapark, Subhashnagar, Pokhran Road No-2, Thane West, Mumbai, Maharashtra, 400601, India.
Environ Monit Assess. 2022 Jan 10;194(2):77. doi: 10.1007/s10661-021-09723-6.
The emergence of COVID-19 has brought the entire planet to a halt. Many countries, including India, were compelled to shut down most urban, industrial, social and other activities as a result of the pandemic. Due to a series of complete lockdowns imposed in India from March 24 to May 17, 2020, and state-wise local level restrictions afterward, have resulted in significant reduction of emissions of numerous atmospheric pollutants. The objective of this study is to analyse the change in concentration of various pollutants such as nitrogen oxide (NO), carbon monoxide (CO) and aerosol optical depth (AOD) due to lockdown and also to quantify the contribution of crop stubble burning to air pollution. The Sentinel-5P based NO and CO observations for 2019 and 2020 and Moderate Resolution Imaging Spectroradiometer (MODIS)-based AOD observations for 2016-2020 were used for detecting the variations. The obtained results showed a significant decrease in NO levels during various stages of lockdown. Small decrease in CO levels was observed across most part of the India. With a few exceptions, such as coastal and desert regions, there was a moderate decrease in AOD levels. Furthermore, to study the contribution of NO, CO and AOD from crop stubble burning, MODIS observations on active fire events were obtained from Visible Infrared Imaging Radiometer Suite (VIIRS). The burning of crop stubble increased NO emissions by 22 to 80%. CO levels, on the other hand, have risen by 7 to 25%. A considerable variation in AOD was reported, ranging from 1 to 426%.
新冠疫情的爆发使整个地球陷入停顿。许多国家，包括印度，都被迫关闭了大部分城市、工业、社会和其他活动。由于印度从 2020 年 3 月 24 日至 5 月 17 日实施了一系列全面封锁，以及随后在各邦实施的地方性限制措施，导致许多大气污染物的排放量显著减少。本研究旨在分析由于封锁而导致的各种污染物（如氮氧化物（NO）、一氧化碳（CO）和气溶胶光学深度（AOD））浓度的变化，并量化农作物秸秆燃烧对空气污染的贡献。本研究使用 Sentinel-5P 基于 NO 和 CO 的观测以及 Moderate Resolution Imaging Spectroradiometer（MODIS）基于 AOD 的观测，对 2019 年和 2020 年进行了检测。研究结果表明，在封锁的各个阶段，NO 水平显著下降。在印度大部分地区，CO 水平略有下降。除了沿海和沙漠地区等少数例外，AOD 水平适度下降。此外，为了研究农作物秸秆燃烧产生的 NO、CO 和 AOD 的贡献，从 Visible Infrared Imaging Radiometer Suite（VIIRS）中获取了 MODIS 对活跃火灾事件的观测。农作物秸秆燃烧增加了 22%至 80%的 NO 排放。另一方面，CO 水平上升了 7%至 25%。报告了相当大的 AOD 变化，范围从 1 到 426%。
