Stratospheric AOD files
Olivier Boucher 
May 2013

see http://data.giss.nasa.gov/modelforce/strataer/

These files correspond to the "Sato" climatology which consists of monthly mean
latitudinal distributions of the stratospheric AOD at 550 nm in four vertical 
layers. The climatology has been regridded on the LMDZ grid and can be used 
as an input to the model (routine readaerosolstrato.F90). 

They are available at horizontal resolutions of 48x36, 96x95 and 144x142, 
and 39 layers, but can be regridded to any horizontal or vertical resolution
using the regrid tool available in the Boite a Outil LMDZ. 

Currently the dataset is only available for the period 1850 to 2010 
but can be extended as the original Sato dataset gets extended.

Regridding has three steps: 
- conversion of the Sato ascii file into netcdf (Ionela Musat)
- horizontal regridding using cdo 
- vertical regridding using an idl script

The regridding conserves the total AOD. Although the Sato climatology 
is a latitudinal mean, one can in principle introduce longitudinal 
variations in the AOD field.