MSIS00 is a simplified IDL interface to the Fortran code of Al Hedin's
two-dimensional thermospheric model MSISE-00, which provides estimates
of the temperature of the atmosphere and of the number density of seven
prevalent species (H, He, N, O, N2, O2, and Ar), and "anomalous" oxygen
above 500 km.  It uses the 10.7 cm radio flux (for the previous day,
and a 81-day smooth centered on the requested day) and the Ap geomagnetic
indices as input, and these data are obtained automatically.

msis00.pro is located on the Sun workstations in $bgkroot/idl/msis.
To use MSIS00 you will need to add this path to your $IDL_PATH (i.e.,
add "+$bgkroot/idl/msis" to your $IDL_PATH environment variable).


Calling sequence:

   msis00, date, sec, glat, glon, alt, t_alt, t_exo, nd, md, $
           ft7p=<ft7p_value>, ft7a=<ft7a_value>, apd=<ap_value[s]>, $
           /SI, /Ap_3hr, /HELP


Positional arguments:
 
   date (input)   -- scalar date of the form yyyyddd or yyddd
 
   sec (input)    -- scalar time of day (UT) in seconds
 
   glat (input)   -- scalar geographic latitude (deg)
 
   glon (input)   -- scalar geographic longitude (deg)
 
   alt (input)    -- scalar or array of requested altitude(s) (km)
 
   t_alt (output) -- scalar or array of same type as alt, with the
                     temperature (K) at each of the input altitudes
 
   t_exo (output) -- scalar, exospheric temperature (K)
 
      Note: if only temperatures are desired, omit the following 
            two output arguments, so that time is not wasted
            computing the number densities.
 
   nd (output)    -- number density, an array of the same length
                     as the input argument alt, each element of
                     which is a structure with seven scalar fields,
                     one for each of seven atmospheric species:
               
                     nd.h  -- atomic hydrogen
                     nd.he -- helium
                     nd.n  -- atomic nitrogen
                     nd.o  -- atomic oxygen
                     nd.n2 -- molecular nitrogen
                     nd.o2 -- molecular oxygen
                     nd.ar -- argon
                     nd.ao -- anomalous oxygen
 
   md (output)    -- scalar or array of same type as alt, with the
                     total mass density of all species at each of
                     the requested altitudes.


Optional input (keyword) arguments:

   ft7p           -- User-supplied value for F10.7 flux value for the
                     previous day (date-1)

   ft7a           -- User-supplied value for 81-day mean of F10.7 flux
                     centered on date

   apd            -- User-supplied value (or array) for Ap index (or
                     3-hourly Ap indices; see msis00.f source code for
                     format) for date

   Note: For any of the above indices not supplied by the user, the
      correct values for the given date are automatically supplied.
 
   /SI            -- to request results in SI units (m^-3); if not
                     supplied, results are in cgs units (cm^-3)

   /Ap_3hr        -- to request that Ap 3-hourly data, rather than
                     just the daily average Ap value be used
 
   /HELP          -- to display this documentation file


For full details on the MSISE-00 model see the Fortran source code
msis00.f (in $bgkroot/src/msis), and the two papers by Al Hedin, 
"MSIS-86 Thermosphere Model" JGR 92, pp 4649-4662 (1987), and "Extension
of the MSIS Thermosphere Model into the Middle and Lower Atmosphere"
JGR 96, pp. 1159-1172 (1991).  Additional documentation and references
are available on the web site (June 2001):

   http://uap-www.nrl.navy.mil/models_web/msis/msis_home.htm


Support:

   msis00.pro is supported by Barry Knapp (knapp@lasp.colorado.edu)