Assessment of the relationship between satellite aerosol optical depth and ground monitored particulate pollution in Beijing, China | |
| Author | Li, Wenbo |
| Call Number | AIT Thesis no.EV-15-28 |
| Subject(s) | Air--Pollution--China--Beijing Pollution--Remote sensing--China--Beijing Satellites--China--Beijing |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Environmental Engineering and Management |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. EV-15-28 |
| Abstract | Particulate matter (PM) air pollution raises increasing concerns worldwide due to its adverse health effects and various influences on the environment and Earth’s climate system. Compared to the traditional ground-based PM observations, satellite monitoring has considerable potential in providing with large spatial coverage of air quality with low costs. The principal objective of this study was to assess ground-level PM pollution in Beijing using satellite aerosol optical depth (AOD), with consideration of meteorological conditions. Daily PM10(PM with aerodynamic diameter less than 10 μm) and PM2.5 (PM with aerodynamic diameter less than 2.5 μm) mass and composition data available for dry and wet months during six years (2001-2006) was extracted from the database of the Asian Regional Air Pollution Research Network (AIRPET). Satellite Moderate Resolution Imaging Spectroradiometer (MODIS) and Multi-Angle Imaging Spectroradiometer (MISR) AODs were extracted from their respective Level-2 aerosol products for the same data period. The satellite AODs were validated using the ground-based Aerosol Robotic Network (AERONET) AOD at Beijing site and showed high correlation coefficients (R) of 0.909 for MODIS and 0.898 for MISR. For relatively clear sky (CF ≤ 3/8), R value for MODIS was improved to 0.924 but no significant effect was shown for MISR. The validated AODs were firstly compared with PM mass without considering meteorological parameters. R values for MODIS AOD-PM varied among four Beijing sites, with R = 0.421-0.912 for AOD-PM2.5 and 0.308-0.881 for AOD-PM10. MISR AOD-PM relationships were only investigated for two sites (MY and BNU) in Beijing that had enough PM measurements, with R = 0.516-0.524 for AOD-PM2.5 and 0.439-0.674 for AOD-PM10. By contrast, MISR generally produced higher R and thus a better fit for PM mass than MODIS. With consideration of meteorological parameters, certain variations in R values of AOD-PM were shown after introducing cloud screening and surface wind speed (WS) for Beijing sites, but not significant. Incorporation of ambient relative humidity (RH) could highly improve R values for both MODIS AOD-PM (rise by 22%) and MISR AOD-PM (by 19%) at all sites. Both WS and RH can enhance the MODIS AOD-PM for DL site. MISR total AOD and component AODs were used to relate with PM constituents (BC, OC, SO42-, NO3-) using simple regression and stepwise regression models, both of which showed the best performances for assessing SO42- with R of 0.862 and 0.947respectively. In addition, MISR component AODs were more strongly associated with OC and NO3-in PM2.5 and BC in PM10 than with BC in PM2.5 and NO3- in PM10. Overall, the finding suggested that MISR component AODs presented a significantly greater predicting capability for ground-level PM pollution (both mass and constituents) as compared to MISR total AOD and MODIS AODs. Further investigations should be extended to other regions in China using more PM data, especially for MISR which have lower visit frequency over the study area. Other covariant factors (e.g., local emission sources and local land uses) and the synoptic meteorological patterns can be considered for better understanding of PM properties and AOD-PM relationships. |
| Year | 2015 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering (EV) |
| Chairperson(s) | Nguyen, Thi Kim Oanh; |
| Examination Committee(s) | Shipin, Oleg V. ;Shrestha, Rajendra Prasad; |
| Scholarship Donor(s) | China Scholarship Council (CSC); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2015 |