The present study was conducted with the purpose to understand the spatial heterogeneity and the inter-state variability of the relative contributions of the long-range transport, fossil fuel and biomass burning on the atmospheric aerosol pollution across India. Satellite and reanalysis datasets (MODIS and MERRA-2) were used to study the total aerosol and its differential components over each of the Indian states under the limited anthropogenic emission condition (April 2020) and compared with the normal condition (April 2015–2019). We observed that the changes in aerosol pollution with the changes in sources from normal to limited anthropogenic activities were not homogeneous across the country. Based on such heterogeneity in “aerosol source-aerosol pollution” relationship, we divided the entire country in four different groups. The states under Group 1 (most of Indo-Gangetic Plain, north-eastern and parts of western and southern India) are found to be mostly influenced by the local/regional anthropogenic sources. The sources other than the biomass burning are the most influential for the aerosol pollution over Group 2 states (Punjab, West Bengal, Rajasthan, Madhya Pradesh, Karnataka and Tripura). Both the biomass burning and long range transport are the major factors for Group 3 state, Telangana. Rest of the states (Group 4) exhibit the relative dominance of the regional and trans-boundary transport over local anthropogenic emissions. Relative influences of fossil fuel and biomass burning over each other and how it changed from the normal to limited activities have also been quantified for each of the states of different groups. The results from the study would be an input of immense importance for the policy makers building state-wise strategies in air pollution control in India.

进行本研究的目的是了解远程运输，化石燃料和生物质燃烧对整个印度大气气溶胶污染的相对贡献的空间异质性和州际变异性。使用卫星和再分析数据集（MODIS和MERRA-2）研究了在有限的人为排放条件（2020年4月）下每个印度州的总气溶胶及其差分成分，并将其与正常条件进行了比较（2015年4月至2019年） 。我们观察到，在全国范围内，气溶胶污染的变化以及人为活动从正常活动到有限人类活动的变化都不均匀。基于“气溶胶源-气溶胶污染”关系中的这种异质性，我们将整个国家分为四个不同的组。发现第1组下的州（大部分是印度恒河平原，印度东北和印度西部和南部的部分地区）受当地/地区人为来源的影响最大。在第二组州（旁遮普邦，西孟加拉邦，拉贾斯坦邦，中央邦，卡纳塔克邦和Tripura），除生物质燃烧以外的其他来源对气溶胶污染的影响最大。生物质燃烧和远距离运输都是第3组州Telangana的主要因素。其余州（第4组）则显示出区域性和跨界运输相对于当地人为排放量的相对优势。化石燃料和生物质相互燃烧的相对影响以及其从正常活动到有限活动的变化方式也已针对不同组的每种状态进行了量化。