Study of aerosol optical depth using satellite data (MODIS Aqua) over Indian Territory and its relation to particulate matter concentration

Air quality all over India has been deteriorated significantly over the last few decades, posing a significant risk to health-related issues like asthma and cardiorespiratory illness. Ground-based monitoring of particulate matter (PM 2.5 and PM 10 ) in India is limited to few particular sites only; hence, health-related studies are restricted to regional scale only. Thus, the major aim of the present study is to estimate the local PM 2.5 and PM 10 mass concentration from the aerosol optical depth (AOD) level. AOD levels are determined from the moderate resolution imaging spectroradiometer (MODIS) onboard Earth Observing System Aqua satellites. Moreover, the annual, seasonal, and diurnal trend of AOD over India was also studied. Single and multiple linear regression models for estimating the concentrations of PM 2.5 and PM 10 were also conducted. Multiple regression analyses were performed considering MODIS-based AOD with meteorological parameters like temperature, relative humidity, wind speed, solar radiation, and precipitation. The results indicated that both the PM 2.5 and PM 10 had a weak correlation with MODIS-based AOD for simple linear regression model, whereas the regression coefficients improved significantly for multiple linear regression analyses. Thus, the proposed multiple linear regression models can be used in the estimation of PM 2.5 and PM 10 concentration in different parts of the country using MODIS image without ground monitoring. Therefore, the predicted results can help to perform the air pollution-related health impact studies all over the country.