Detection of Aerosol Signal from Geostationary Satellite Visible Imagery

The present study aims to build upon the limited attempts made recently to retrieve aerosol signal over the continents (Knapp, 2002) from geostationary orbits, and extend the analyses to other geostationary satellites over the globe. Aerosol signals can be determined by comparing cloud-free imagery from geostationary satellites with ground-based observations from the Aerosol Robotic Network (AERONET) sites available from 1992. This analysis will be extrapolated in time and space to identify emerging patterns and trends in global and regional aerosol loading. Aerosols play an important role in the atmosphere through their direct interaction with solar radiation altering the energy budget and affecting the weather patterns. Aerosols generated from wildfires, dust episodes and biomass burning also impact the human health. Further, observations at AERONET sites indicate diurnal variations of aerosol optical depth ranging between 10 – 20 % which significantly influence the radiative forcing and aerosol interaction with humidity and clouds. During the past decades, aerosol retrieval has been confined to polar orbiters such as the Advanced Very High Resolution Radiometer (AVHRR) and Moderate Resolution Imaging Spectroradiometer (MODIS) instruments, etc. and mostly over the oceans. The study reported here seeks to take advantage of the higher temporal sampling potential of geostationary meteorological satellites to also identify the important diurnal trends in specific regions.