The contribution of interstate pollution transport to surface carbon monoxide (CO) and black carbon (BC) levels in different Indian states and regions is studied by implementing a computationally efficient tagged tracer technique in the Weather Research and Forecasting model coupled with chemistry. Anthropogenic and fire emissions of CO and BC are tracked from each Indian state and the simulated CO and BC concentrations are used to estimate state-wise pairs of source and receptor states in 2014, the most recent year for which anthropogenic emissions are available. We observe strong relationship between direct emissions and concentrations of CO and BC with local emissions contributing 56–68% to the annual averaged CO and BC levels in Uttar Pradesh, Delhi, and West Bengal located in the Indo-Gangetic Plain. Interstate transport contributes 53 ± 23% and 52 ± 25% to annual averaged CO and BC, respectively, in different Indian states. Interstate transport contribution exceeds 60% in one third of the Indian states. Uttar Pradesh, West Bengal, Maharashtra, and Bihar are among the top five contributors to CO and BC levels in most of the Indian states. Seasonal changes in monsoonal circulation also led to a reversal of source-receptor relationship at the state level between winter and summer monsoon seasons. Our findings imply a need to extend India's air quality management framework to address interstate exchange of pollution.

通过在天气研究和预报模型中结合化学方法实施计算有效的标记示踪剂技术，研究了印度不同州和州之间州际污染物运输对表面一氧化碳（CO）和黑碳（BC）水平的贡献。跟踪每个印度州的CO和BC的人为排放量和火灾排放量，并使用模拟的CO和BC浓度估算2014年的人源和受体状态的状态对，这是可获得的最近一年的人为排放量。我们观察到直接排放与CO和BC浓度之间的密切关系，局部排放对位于印度恒河平原的北方邦，德里和西孟加拉邦的年度平均CO和BC水平贡献了56–68％。在印度不同州，州际运输分别为年平均CO和BC贡献53±23％和52±25％。在印度三分之一的州中，州际运输贡献超过60％。北方邦，西孟加拉邦，马哈拉施特拉邦和比哈尔邦是印度大多数州的CO和BC水平前五名贡献者。季风环流的季节性变化还导致了州级冬季和夏季季风季节之间的源-受体关系的逆转。我们的发现表明，有必要扩展印度的空气质量管理框架，以解决州际间的污染交换。比哈尔邦（Bihar）和比哈尔邦（Bihar）在大多数印度邦的CO和BC排放水平中均排名前五。季风环流的季节性变化还导致了州级冬季和夏季季风季节之间的源-受体关系的逆转。我们的发现表明，有必要扩展印度的空气质量管理框架，以解决州际间的污染交换。比哈尔邦（Bihar）和比哈尔邦（Bihar）在大多数印度邦的CO和BC排放水平中均排名前五。季风环流的季节性变化还导致了州级冬季和夏季季风季节之间的源-受体关系的逆转。我们的发现表明，有必要扩展印度的空气质量管理框架，以解决州际间的污染交换。