----------------------
File name:
----------------------
yyyymm.XX.vs.g      6-hourly concentrations in g/m3
yyyymm.XX.vs.g.day  daily avg concentrations in g/m3
yyyymm.XX.vs.g.avg  monthly avg concentrations in g/m3

where yyyymm = year and month (e.g., 200103)
      XX = SU (sulfur), CC (carbonaceous), DU (dust), SS (sea-salt)
      vs = version (e.g., STD.tv12)

----------------------
Species Included:
----------------------
SU (sulfur): Total 4, 1-DMS, 2-SO2, 3-SO4, 4-MSA.
CC (BC+OC): Total 4, 1-hydrophobic BC, 2-hydrophobic OC,
                     3-hydrophilic BC, 4-hydrophilic OC.
DU (dust): Total 5, 1-Re=0.1-1, 2-Re=1-1.8, 3-Re=1.8-3, 4-Re=3-6, 5-Re=6-10 um.
SS (sea-salt): Total 4, 1-Re=0.1-0.5, 2-Re=0.5-1.5, 3-Re=1.5-5, 4-Re=5-10 um.

NOTE: for dust, the first group (0.1-1 um) contains the following subgroups:
0.10-0.18 um (fraction =0.01053)
0.18-0.30 um (fraction =0.08421)
0.30-0.60 um (fraction =0.25263)
0.60-1.00 um (fraction =0.65263)

----------------------
Data format:
----------------------
These are direct access binary files, 32 bits, big endian.

dimension Q(imx,jmx,lmx)
do k=1,nstep
 do n=1,nmx
  read(unit) nt1,nt2,nn,Q
 end do
enddo

Where imx = total number of longitudinal grid (144),
      jmx = total number of latitudinal grid (91),
      lmx = total number of vertical layers (version dependent),
      nmx = total number of species (4 or 5, see species list above),
      nt1 = yyyymmdd after 2000 (year-month-day, e.g., 20010201), or
            yymmdd before 2000 (e.g., 970101)
      nt2 = hhmmss (hour-minute-second, e.g., 120000)
      nn  = tracer number (see species list above)
      Q   = 3-dimensional concentration of tracer nn
      nstep = total time step (e.g., in 200101, nstep=4*31 for 4-times/day,
              nstep=31 for daily average files, and nstep=1 for monthly
              average files ).
Note: nt1,nt2,nn are long integers.

To read using IDL:

imx=144 & jmx=91 & lmx=30
Q = fltarr(imx,jmx,lmx)
head=lonarr(3)
for k=0,nstep-1 do begin
 for n=0,nmx-1 do begin
  readu,1,head
  readu,1,Q
 endfor
endfor

!!!! IMPORTANT !!!!
Since there are some difference in default format of data saving, Fortran
compiler on your workstation may not be the same as that on the Cray where
these files are saved.  Please print out the nt1, nt2 for every timestep to 
be sure that the files are read correctly.

If you use fortran on a SGI machine, please use the following statement when
read the binary file:

open(unit,file='xyz',status='old',access='sequential',form='system')

If you use linux or PC, you have to convert the data to little endian.