Diurnal Variations in the Air Pollutants Concentration over Haryana, India, and Understanding their Emission Sources.

India's Indo-Gangetic Plain (IGP) region has become the global hotspot of air pollution, and stubble burning in northern India has increased the concern due to its impact on air quality and health. The current study focuses on studying the diurnal variation of air pollutants for the first time covering Haryana, India, and identifying the sources responsible for air pollutants emissions during the different seasons of the year. Based on ecology and cropping pattern, the study area was divided in three zones. In all seasons, the diurnal peak concentrations of particulate matter (PM_2.5 and PM₁₀) were found highest in Zone 2 as compared to Zone 1 and Zone 3, which can be due to the high polluting districts located in Zone 2 including Hisar where thermal power plants, stainless steel producing industry and pulp and paper industry are located along with district Faridabad which is known as the industrial capital of Haryana. The lowest average hourly concentration of PM₁₀ and PM_2.5 was found in late afternoon hours in winter, pre-monsoon and post-monsoon season in all three zones due to a decrease in traffic volumes which lead to low emission rates along with increase in the mixing height which cause favorable dispersion conditions. The lowest hourly mean concentration of CO, NO_x and NH₃ in all zones was found during the afternoon hours in all seasons. The study also focuses on understanding the day and time patterns and the maxima and minima of pollutants concentrations in different zones of Haryana. [ABSTRACT FROM AUTHOR]