Vertical profiles of aerosol and NO2 based on mobile multi-axis differential absorption spectroscopy

Abstract

Mobile acquisition of vertical distribution profiles of air pollutants in urban areas is of great significance for studying the transmission and traceability of urban pollutants. In this study, a portable mobile multi-axis differential optical absorption spectroscopy (MAX-DOAS) system was used to establish an algorithm based on the mobile system to retrieve air pollution profiles, which could quickly trace the source of pollutants in urban areas. First, this study used the mobile MAX-DOAS system to continuously measure a planned urban route from multiple angles in real time and collect the vertical distribution information of aerosols and NO2 in different positions. Then, the established algorithm and the vertical distribution information of the pollutants were used to retrieve the air pollution profiles via the minimum cost function. Finally, the pollution source orientation was traced, and the pollution transmission process was analyzed based on the wind field data of the model. Experimental results showed a significant correlation between tropospheric monitoring instrument (TROPOMI) and mobile measurements based on a coefficient of determination value of 0.85. It was found that the air quality of Xuzhou and Huaihai Economic Zone was adversely affected by the transport of the pollutants northeast of Xuzhou. This study realizes portable mobile retrieval of the aerosol and NO2 profiles in urban areas, improves the accuracy of pollution traceability, and provides insights into retrieving the trace gas profiles via a mobile MAX-DOAS system.