Publications

Zhang, Ming; Huang, Bo; Jiang, Renrong (2015). Using satellite data to estimate particulate air quality in a subtropical city: an evaluation of accuracy and sampling issues. REMOTE SENSING LETTERS, 6(5), 370-379.

Abstract
Although satellite data are increasingly being used for particulate air quality studies, the applicability of satellite-derived aerosol optical depth (AOD or tau) products for use over tropical or subtropical cities with frequent cloud cover should be carefully examined. Using eight years of ground-based and satellite-based observations, we assess the accuracy and sampling issues of using satellite data to study particulate air quality over a typical subtropical city, Hong Kong, at monthly to yearly timescales. The validation of Moderate Resolution Imaging Spectroradiometer (MODIS) AOD products shows that 64.6% of the retrievals fall within an expected error envelope of +/- (0.05+0.15 tau) and that they have a low bias during the eight-year study period, thus suggesting that the accuracy of current satellite-derived AOD data still needs to be improved. In addition, the availability of satellite observations is typically less than 30% during the months in spring and summer and less than 35% over seasonal and yearly timescales due to the cloudy and rainy weather. Inadequate sampling issues result in large biases over monthly and seasonal timescales; however, satellite data do not have major sampling issues on the yearly timescale despite the positive bias due to the washout effects of rain.

DOI:
10.1080/2150704X.2015.1035771

ISSN:
2150-704X