title: Comparison of ground based indices (API and AQI) with satellite based aerosol products.
abstract: Air quality in mega cities is one of the major concerns due to serious health issues and its indirect impact to the climate. Among mega cities, Beijing city is considered as one of the densely populated cities with extremely poor air quality. The meteorological parameters (wind, surface temperature, air temperature and relative humidity) control the dynamics and dispersion of air pollution. China National Environmental Monitoring Centre (CNEMC) started air pollution index (API) as of 2000 to evaluate air quality, but over the years, it was felt that the air quality is not well represented by API. Recently, the Ministry of Environmental Protection (MEP) of the People's Republic of China (PRC) started using a new index "air quality index (AQI)" from January 2013. We have compared API and AQI with three different MODIS (MODIS - Moderate Resolution Imaging SpectroRadiometer, onboard the Terra/Aqua satellites) AOD (aerosol optical depth) products for ten months, January-October, 2013. The correlation between AQI and Aqua Deep Blue AOD was found to be reasonably good as compared with API, mainly due to inclusion of PM2.5 in the calculation of AQI. In addition, for every month, the correlation coefficient between AQI and Aqua Deep Blue AOD was found to be relatively higher in the month of February to May. According to the monthly average distribution of precipitation, temperature, and PM10, the air quality in the months of June-September was better as compared to those in the months of February-May. AQI and Aqua Deep Blue AOD show highly polluted days associated with dust event, representing true air quality of Beijing.
authors.affiliation: State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing and Digital Earth of Chinese Academy of Sciences and Beijing Normal University, Datun Road, Chaoyang District, Beijing 100101, PR China; University of Chinese Academy of Sciences, No.19A, Yuquan Road, Shijingshan District, Beijing 100049, PR China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing and Digital Earth of Chinese Academy of Sciences and Beijing Normal University, Datun Road, Chaoyang District, Beijing 100101, PR China; Center for Applications of Spatial Information Technologies in Public Health, Datun Road, Chaoyang District, Beijing 100101, PR China.
authors.forename: Chun-Xiang
authors.initials: CX
authors.lastname: Cao
authors.affiliation: School of Earth and Environmental Sciences, Schmid College of Science and Technology, Chapman University, One University Drive, Orange, CA 92866, USA. Electronic address: rsingh@chapman.edu.
authors.forename: Ramesh P
authors.initials: RP
authors.lastname: Singh
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis*; D000397:Air Pollution / Q000706:statistics & numerical data*; D004784:Environmental Monitoring / Q000379:methods*; D052638:Particulate Matter / Q000032:analysis; D063809:Satellite Imagery
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter
keywords: AOD; API; AQI; MODIS