Aerosol Optical Depth as interpolated from GEOS5 for the<br>
aer_opt2 case<br>
4-km domain, forecast hour 24<br>
aer_opt2 Case uses:<br>
 GEOS 3-hourly aerosol optical depth<br>
 fixed aerosol angstrom exponent   = 1.3<br>
 fixed single scattering albedo    = 0.85<br>
 fixed aerosol asymmetry parameter = 0.9<br>
<b>NOTE:</b> In this first test, the AOD field was not smoothed at
all.  In all other tests, it is smoothed using a standard 4-pt
smoother in METGRID.