| Title | Estimation of ultrahigh resolution PM 2.5 concentrations in urban areas using 160 m Gaofen-1 AOD retrievals |
| Authors | 朱忠敏 |
| Issue Date | 2018 |
| Publisher | Remote Sensing of Environment |
| Keywords | Aerosol optical depth Ultrahigh spatial resolution Gaofen-1 WFV Nested LME model Urban-scale PM 2.5 |
| Citation | Remote Sensing of EnvironmentVolume 216, 2018. PP 91-104 |
| Abstract | Satellite-derived aerosol optical depth (AOD) has been widely used to estimate ground-level PM 2.5 concentrations due to its spatially continuous observation. However, the coarse spatial resolutions (e.g., 3 km, 6 km, or 10 km) of the primary satellite AOD products have weakness to capture the characteristics of urban-scale PM 2.5 patterns. Moreover, high-resolution (e.g., 1 km) PM 2.5 estimations are still unable to be related to the urban landscape or to small geographical units, which is crucial for analyzing the urban pollution structure. In this study, the daily PM 2.5 concentrations were estimated using the new AOD data with a 160 m spatial resolution retrieved by the Gaofen-1 (GF) wide field of view (WFV) along with the nested linear mixed effects model and ancillary variables from the Weather Research & Forecasting (WRF) meteorological simulation data. The experiment was conducted in Wuhan, Beijing, and Shanghai, which suffers from severe atmospheric fine particle pollution in recent years. The proposed model performed well for both GF and Moderate Resolution Imaging Spectroradiometer (MODIS), with slight over-fitting and little spatial autocorrelation. Regarding to the GF PM 2.5 estimation, model fitting yielded R 2 values of 0.96, 0.91 and 0.95 and mean prediction error (MPE) of 10.13, 11.89 and 7.34 μg/m 3 for Wuhan, Beijing and Shanghai, respectively. The site-based cross validation achieved R 2 values of 0.92, 0.88 and 0.89, and MPE of 13.69, 16.76 and 12.59 μg/m 3 for Wuhan, Beijing and Shanghai, respectively. The day-of-years based cross validation resulted in R 2 of 0.54, 0.58 and 0.50, and MPE of 30.46, 27.12 and 31.58 μg/m 3 for Wuhan, Beijing and Shanghai, respectively, indicating that it was practicable to estimate the GF PM 2.5 in the days without enough AOD-PM 2.5 matchups. The ultrahigh resolution PM 2.5 estimations offer substantial advantages for providing finer spatially resolved PM 2.5 trends. Additionally, it offers new approaches to locate main PM 2.5 emission sources, evaluate the local PM 2.5 contribution proportion, and quantify the daily PM 2.5 emission level via remote sensing techniques. Along with the joint observations via other high-resolution satellites, the temporal resolution of GF PM 2.5 will be further improved. In all, this study not only provides possibilities for further applications in the precise analysis of urban inner PM 2.5 pollution patterns but also establishes a foundation for constructing a high-resolution satellite air monitoring network in China. |
| ISSN | 0034-4257 |
| Appears in Collections: | 信息系 |
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