Sunday, 9 February 2003
MODIS Observations of Global Tropospheric Aerosols in 2001
It is of interest to monitor aerosols (i.e. desert dusts and sulfate aerosols from industrial emissions) over land and ocean because aerosol particles influence the temperature structure and chemistry of the Earth’s troposphere. MODIS (Moderate Resolution Imaging Spectroradiometer) observations of vertical column aerosol optical depths during 2001 were analyzed on a global and seasonal basis, and compared to regional sources of industrial tropospheric pollution. There was a general correspondence between annually averaged MODIS aerosol optical depth map and that of the ECHAM/GRANTOUR computer model. Both maps indicated high aerosol content over Africa and Asia. Furthermore, a general positive correlation was found when MODIS aerosol optical depth data for year 2001 were compared to recently published regional sulfur dioxide (SO2) emission values. Analysis of TOMS aerosol index, however, demonstrated that regional values of MODIS aerosol optical depth were influenced by the presence of desert dusts. Regional values were also influenced by the transport of aerosols from one region to another (e.g. from China to Japan). These results implied that future work, that will accurately distinguish aerosol types and factor in wind effects, is needed to use the MODIS instrument to study the impact of anthropogenic industrial SO2 emissions upon tropospheric aerosol amount.