Retrieval of aerosol optical thickness over Hong Kong and Pearl River Delta region using MODIS satellite data

Aerosol retrieval algorithms for the MODerate Resolution Imaging Spectroradiometer (MODIS) satellite have been developed to estimate aerosol and microphysical properties of the atmosphere which help to address aerosol climatic issues at global scale. However, higher spatial resolution aerosol products for urban areas have not been well researched. In this study, a new aerosol retrieval algorithm for the MODIS 500m resolution data has been developed to retrieve aerosol properties over complex land, which helps to address the aerosol climatic issues for both local and regional areas. The results show that 500m Aerosol Optical Thickness (AOT) data from MODIS are highly correlated (r = 0.96 and r = 0.87) with AERONET and MicrotopsII sunphotometer observations in Hong Kong. This study demonstrates the feasibility of aerosol retrieval at ''fine'' resolution in urban areas, which can help study aerosol distribution and pinpoint pollution sources.