Characterization of Diurnal Aerosol Phenomena using Geostationary Retrievals of Aerosol Optical Depth

A new generation of satellite sensors in geostationary orbit has led to quantitative aerosol retrievals of an accuracy and precision previously only attainable from polar orbiting satellites. The new aerosol retrieval products from these sensors can be used to examine diurnally varying phenomena, and test the assumptions used to draw conclusions about the atmospheric aerosol based on observations near solar noon. This study draws on aerosol products from the Korean COMS-1 platform, including both the Meteorological Imager (MI) and the Global Ocean Color Imager (GOCI) sensors. These products are first compared with the products from MODIS Collection 6 to identify biases between these products that may affect the analysis. Then the geostationary data are analyzed to quantify the extent to which aerosol optical depth varies systematically from its value at local solar noon, and to identify areas, seasons, and meteorological phenomena that result in significant diurnal variation. These results have implications for the study of aerosol phenomena, aerosol-cloud interaction, and the use of geostationary observations to constrain analyses and forecasts of atmospheric aerosol.