Severe pollution events occur frequently in India but few studies have investigated the characteristics, sources, and control strategies for the whole country. A year-long simulation was carried out in India to provide detailed information of spatial and temporal distribution of gas species and particulate matter (PM). The concentrations of O_3, NO_2, SO_2, CO, as well as PM_(2.5) and its components in 2015 were predicted using Weather Research Forecasting (WRF) and the Community Multiscale Air Quality (CMAQ) models. Model performance was validated against available observations from ground based national ambient air quality monitoring stations in major cities. Model performance of O_3 does not always meet the criteria suggested by the US Environmental Protection Agency (EPA) but that of PM_(2.5) meets suggested criteria by previous studies. The performance of model was better on days with high O_3 and PM_(2.5) levels. Concentrations of PM_(2.5), NO_2, CO and SO_2 were highest in the Indo-Gangetic region, including northern and eastern India. PM_(2.5) concentrations were higher during winter and lower during monsoon season. Winter nitrate concentrations were 160–230% higher than yearly average. In contrast, the fraction of sulfate in total PM_(2.5) was maximum in monsoon and least in winter, due to decrease in temperature and solar radiation intensity in winter. Except in southern India, where sulfate was the major component of PM_(2.5), primary organic aerosol (POA) fraction in PM_(2.5) was highest in all regions of the country. Fractions of secondary components were higher on bad days than on good days in these cities, indicating the importance of control of precursors for secondary pollutants in India.

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印度气态和颗粒空气污染物的长达一年的模拟

印度严重污染事件频发，但很少有研究调查了整个国家的特征、来源和控制策略。在印度进行了为期一年的模拟，以提供有关气体种类和颗粒物 (PM) 时空分布的详细信息。使用天气研究预报 (WRF) 和社区多尺度空气质量 (CMAQ) 模型预测 2015 年 O_3、NO_2、SO_2、CO 以及 PM_(2.5) 及其成分的浓度。模型性能根据主要城市地面国家环境空气质量监测站的可用观测结果进行了验证。O_3 的模型性能并不总是符合美国环境保护署 (EPA) 建议的标准，但 PM_(2.5) 的模型性能符合先前研究建议的标准。在 O_3 和 PM_(2.5) 水平高的日子里，模型的性能更好。PM_(2.5)、NO_2、CO和SO_2的浓度在印度-恒河地区最高，包括印度北部和东部。PM_(2.5)浓度在冬季较高，在季风季节较低。冬季硝酸盐浓度比年平均水平高 160-230%。相比之下，由于冬季温度和太阳辐射强度降低，硫酸盐在总 PM_(2.5) 中的比例在季风期间最大，在冬季最小。除了在印度南部，硫酸盐是 PM_(2.5) 的主要成分，PM_(2.5) 中的初级有机气溶胶 (POA) 分数在该国所有地区都是最高的。在这些城市，次要成分的比例在糟糕的日子里比在美好的日子里要高，