The file "STEM-Aerosol.INDOEX-90x60.nc"
includes STEM-2K3 chemical and RAMS meteorological fields for INDOEX periods. 
All the data files are in EPA IOAPI format (http://www.baronams.com/products/ioapi/AA.html#conventions),
 a convention of NetCDF. You can read them with NetCDF code. Their coordinate
 information can be found in (http://www.baronams.com/products/ioapi/INCLUDE.html#parms).
 You can use ncdump to view this information, too. For example, under UNIX

$ ncdump -h STEM-Aerosol.INDOEX-90x60.nc

You will the following print out :

dimensions:
        TSTEP = UNLIMITED ; // (336 currently)
        DATE-TIME = 2 ;
        LAY = 15 ;
        VAR = 19 ;
        ROW = 60 ;
        COL = 90 ;

which means that this file includes 241 time steps, X-dimension (COL) is 90,
Y-dimension (ROW) is 60, and Z-dimension (LAY) is 17. You will also find

// global attributes:
                :IOAPI_VERSION = "2.2 2002080 (March 21, 2002)" ;
                :EXEC_ID = "????????????????
                       " ;
                :FTYPE = 1 ;
                :CDATE = 2005210 ;
                :CTIME = 175932 ;
                :WDATE = 2005210 ;
                :WTIME = 175932 ;
                :SDATE = 1999045 ;
                :STIME = 30000 ;
                :TSTEP = 30000 ;
		
"SDATE" is file starting date in YYYYDDD, where DDD is the julian day, and 1999045
is Feb 14, 1999; "STIME" is the start time in HHMMSS, and "TSTEP" is time step also in
HHMMSS.	In the following grid information,

 :VGTOP = 18644.21f ;
 :VGLVLS = 50.f, 160.f, 292.f, 450.4f, 640.48f, 868.576f, 1142.291f, 1470.75f, 1864.9f, 2337.88f, 2905.456f, 3586.547f, 4403.856f, 5384.628f, 6561.554f, 7973.865f
 
 You will find that the model vertical grid (RAMS's sigma-z) has sigma-top at 18644.21 m,
 and its half-sigma level over sea surface is 50m, 160m, ........................ 
 Please view the webpage meantioned above and the sample reading program "read-stem-rams-1.f" and
 "read-stem-rams-1.cs" for detailed information. To compile the reading program, you need
 install netcdf and EPA IOAPI (http://www.baronams.com/products/ioapi/AVAIL.html).
 
STEM-2K3 (Tang et al., 2004, JGR 109, D19S23, doi:10.1029/2003JD004201)
has 4-bin aerosols: 0.1-0.3um, 0.3-1.0um, 1.0-2.5um, and 2.5-10um in diameter. In these files,
BC1 means the black carbin in 0.1-0.3um, and Na4 is the sodium in the bin of 2.5-10um.

 If you have any question about the data. contact Youhua Tang (ytang@cgrer.uiowa.edu)