Column total sulfate aerosol at present-day level is based on the model-derived data (available at http://gacp.giss.nasa.gov/transport/) by the GACP transport model (Tegen et al., 1997). The geographical distributions for annual-mean and monthly are shown below. The aerosol mass in the column is vertically distributed with a homogeneous mixing ratio in the lowest 740 m thickness of the atmosphere.
Annual mean distribution of column total sulfate mass loading (unit: 10-3 gm-2) for natural source (upper), anthropogenic (middle) and total (lower).
Monthly distribution of column total sulfate mass loading (unit: 10-3 gm-2).