The TROPOMI (TROPOspheric monitoring instrument) onboard Sentinel-5 Precursor (S5P) satellite provides high spatial resolution data of carbon monoxide (CO) while the MAIAC (Multiangle Implementation of Atmospheric Correction) is a newly developed algorithm applied to MODIS collection 6 observations to retrieve AOD (Aerosol Optical Depth) at a high spatial resolution of 1 km. The present study utilized the MAIAC AOD from MODIS Terra and Aqua polar-orbiting satellites between March 2000 to December 2021 and CO from Sentinel-5P during the available period July 2018-December 2021 over Pakistan. Moreover, we used three trend techniques (Linear regression, Mann–Kendall (MK), and Theil-Sen’s Slope) to examine the trends of AOD and CO over Pakistan. The results show that both AOD and CO have high values over central Punjab, western Balochistan, central Sindh, and Khyber Pakhtunkhwa. The mean annual high AOD of > 1.2 is observed in eastern Punjab because of an increase in urbanization, industrialization, and economical activities whereas the AOD of ~ 1.0 is observed over Balochistan, Sindh, and a few parts of Khyber Pakhtunkhwa. The highest mean annual CO of ˃0.03 mol/m^2 is seen over central Punjab, Sindh, and Khyber Pakhtunkhwa. The results show that seasonal mean MAIAC AOD ranging from 0.7 to > 0.9 was seen over Punjab and Sindh province during the monsoon season whereas the lowest AOD is detected in the winter season over few parts of Balochistan. In contrast, the highest mean seasonal CO ranging from 0.040 to > 0.055 mol/m^2 was seen in the winter season over Punjab. The lowest CO concentration is observed in the winter season over the northern region of Pakistan. Non-parametric analyses (MK and Theil-Sen’s slope) also show an increasing trend of CO over Pakistan from 2018 to 2021. Furthermore, we have also investigated the trends of AOD and CO over selected cities of Pakistan using linear regression, MK test, and Theil-Sen’s slope to reveal long-term air pollution trends.

Sentinel-5 Precursor (S5P) 卫星上的 TROPOMI（对流层监测仪器）提供一氧化碳 (CO) 的高空间分辨率数据，而 MAIAC（大气校正的多角度实施）是一种新开发的算法，应用于 MODIS 收集 6 次观测以检索AOD（气溶胶光学深度）具有 1 公里的高空间分辨率。本研究利用了 2000 年 3 月至 2021 年 12 月期间来自 MODIS Terra 和 Aqua 极轨卫星的 MAIAC AOD，以及 2018 年 7 月至 2021 年 12 月在巴基斯坦可用期间来自 Sentinel-5P 的 CO。此外，我们使用三种趋势技术（线性回归、Mann-Kendall (MK) 和 Theil-Sen 斜率）来检查巴基斯坦 AOD 和 CO 的趋势。结果表明，AOD 和 CO 在旁遮普中部、俾路支省西部、信德省中部和开伯尔-普赫图赫瓦省。由于城市化、工业化和经济活动的增加，在旁遮普邦东部观察到 > 1.2 的年平均高 AOD，而在俾路支省、信德省和开伯尔-普赫图赫瓦省的一些地区观察到的 AOD 约为 1.0。在旁遮普邦中部、信德省和开伯尔-普赫图赫瓦省，最高的年平均二氧化碳浓度为˃0.03 mol/m^2。结果表明，在季风季节，旁遮普省和信德省的季节性平均 MAIAC AOD 范围从 0.7 到 > 0.9，而在俾路支省少数地区的冬季，AOD 最低。相比之下，在旁遮普省的冬季，最高平均季节性 CO 范围从 0.040 到 > 0.055 mol/m^2。在巴基斯坦北部地区的冬季观察到最低的二氧化碳浓度。