Beihang University, Haidian District, Beijing, China.
Institute of Space Technology, Islamabad, Pakistan.
Environ Monit Assess. 2024 Feb 21;196(3):291. doi: 10.1007/s10661-024-12458-9.
This study conducts a spatio-temporal analysis of tropospheric nitrogen dioxide (NO) and total carbon monoxide (CO) concentrations in the Punjab and Haryana regions of India and Pakistan, using datasets from the Sentinel 5-Precursor (S5P) satellite. These regions, marked by diverse economic growth factors including population expansion, power generation, transportation, and agricultural practices, face similar challenges in atmospheric pollution, particularly evident in major urban centers like Delhi and Lahore, identified as pollution hotspots. The study also spotlights pollution associated with power plants. In urban areas, tropospheric NO levels are predominantly elevated due to vehicular emissions, whereas residential activities mainly contribute to CO pollution. However, precisely attributing urban CO sources is complex due to its longer atmospheric residence time and intricate circulation patterns. Notably, the burning of rice crop residue in November significantly exacerbates winter pollution episodes and smog, showing a more pronounced correlation with total CO than with tropospheric NO levels. The temporal analysis indicates that the months from October to December witness peak pollution, contrasted with the relatively cleaner period during the monsoon months of July to September. The severe pollution in the OND quarter is attributed to factors such as variations in boundary layer height and depletion of OH radicals. Furthermore, the study highlights the positive impact of the COVID-19 lockdown on air quality, with a significant decrease in NO concentrations during April, 2020 (Delhi: 59%, Lahore: 58%). However, the reduction in total CO columns was less significant. The study also correlates lockdown stringency with tropospheric NO columns (R2: 0.37 for Delhi, 0.25 for Lahore, 0.22 for Rawalpindi/Islamabad), acknowledging the influence of various meteorological and atmospheric variables. The research highlights the significant impact of crop residue burning on winter pollution levels, particularly on total CO concentrations. The study also shows the notable effect of the COVID-19 lockdown on air quality, significantly reducing NO levels. Additionally, it explores the correlation between lockdown stringency and tropospheric NO columns, considering various meteorological factors.
本研究利用 Sentinel 5-Precursor(S5P)卫星数据集,对印度旁遮普邦和哈里亚纳邦以及巴基斯坦的对流层二氧化氮(NO)和总一氧化碳(CO)浓度进行时空分析。这些地区的经济增长因素多样,包括人口扩张、发电、交通和农业活动,面临着类似的大气污染挑战,特别是在德里和拉合尔等主要城市中心,这些地区被确定为污染热点。该研究还强调了与电厂相关的污染问题。在城市地区,由于车辆排放,对流层中的 NO 水平主要升高,而住宅活动主要导致 CO 污染。然而,由于 CO 在大气中的停留时间较长且循环模式复杂,准确归因于城市 CO 源较为复杂。值得注意的是,11 月焚烧水稻作物残留物会显著加剧冬季污染事件和烟雾,与总 CO 的相关性比与对流层 NO 水平的相关性更显著。时间分析表明,10 月至 12 月是污染高峰期,与 7 月至 9 月的季风期间相对清洁的时期形成对比。OND 季度的严重污染归因于边界层高度变化和 OH 自由基消耗等因素。此外,该研究强调了 COVID-19 封锁对空气质量的积极影响,2020 年 4 月,NO 浓度显著下降(德里:59%,拉合尔:58%)。然而,总 CO 柱的减少并不明显。该研究还将封锁严格程度与对流层 NO 柱相关联(德里:R2=0.37,拉合尔:R2=0.25,拉瓦尔品第/伊斯兰堡:R2=0.22),承认各种气象和大气变量的影响。该研究强调了冬季作物残留物燃烧对污染水平,特别是对总 CO 浓度的显著影响。该研究还表明 COVID-19 封锁对空气质量有显著影响,显著降低了 NO 水平。此外,它还探讨了封锁严格程度与对流层 NO 柱之间的相关性,同时考虑了各种气象因素。