Retrieval of High-Resolution Atmospheric Particulate Matter Concentrations from Satellite-Based Aerosol Optical Thickness over the Pearl River Delta Area, China

Abstract

Satellite remote sensing offers an effective approach to estimate indicators of air quality on a large scale. It is critically significant for air quality monitoring in areas experiencing rapid urbanization and consequently severe air pollution, like the Pearl River Delta (PRD) in China. This paper starts with examining ground observations of particulate matter (PM) and the relationship between PM10 (particles smaller than 10 μm) and aerosol optical thickness (AOT) by analyzing observations on the sampling sites in the PRD. A linear regression (R 2 = 0.51) is carried out using MODIS-derived 500 m-resolution AOT and PM10 concentration from monitoring stations. Data of atmospheric boundary layer (ABL) height and relative humidity are used to make vertical and humidity corrections on AOT. Results after correction show higher correlations (R 2 = 0.55) between extinction coefficient and PM10. However, coarse spatial resolution of meteorological data affects the smoothness of retrieved maps, which suggests high-resolution and accurate meteorological data are critical to increase retrieval accuracy of PM. Finally, the model provides the spatial distribution maps of instantaneous and yearly average PM10 over the PRD. It is proved that observed PM10 is more relevant to yearly mean AOT than instantaneous values.

Estimation and inter-comparison of dust aerosols based on MODIS, MISR and AERONET retrievals over Asian desert regions

“…Many researchers reported the long term trend of AERONET AOD on regional scale and worldwide (Li et al, 2015;Xia, 2011;Yoon et al, 2012). AOD trend retrieved from multiple sensors have been found decreasing over the Western Europe and US and increasing over the Indian Subcontinent, Middle East and some parts of China.…”

Estimation of PM10 Distribution using Landsat5 and Landsat8 Remote Sensing

“…The main objective of this study is to design and validate a predictive algorithm for mapping PM10 concentration using a database of Landsat satellite images. This investigation is unique and differs from previous studies [5][6][7] in term of high data resolution. In situ measurements provided by ground quality stations have been required for algorithm validation.…”

Spatial Accessibility of Urban Forests in the Pearl River Delta (PRD), China

“…The Pearl River Delta (PRD), located in Guangdong Province, China, is one of the fastest-growing urban regions in the world [27,28]. The land use land cover changes (LULCC) associated with the urbanization processes have caused many environmental and societal problems (e.g., air pollution, loss of natural habitat, and acid rain) because economic development was the main priority [29][30][31]. The PRD is also one of the few regions in China with rich vegetation and abundant tree cover due to its subtropical climate; yet, the loss of tree cover has been increasing in recent years, especially since 2013 ( Figure 1).…”

“…To address this research need, our specific objectives were to: (i) delineate the distance proximity-a proxy of access by walking-to forests from any location or a point of interest (POI) in the PRD; (ii) quantify travel time to forests from different origins; and (ii) test the hypothesis that forest accessibility is dependent on population density and economic status. (e.g., air pollution, loss of natural habitat, and acid rain) because economic development was the main priority [29][30][31]. The PRD is also one of the few regions in China with rich vegetation and abundant tree cover due to its subtropical climate; yet, the loss of tree cover has been increasing in recent years, especially since 2013 ( Figure 1).…”