Data Set Overview
    =================
      The Ames Mars General Circulation Model is a three dimensional
      model based on the primitive equations of meteorology.  It
      includes the radiative effects of dust and carbon dioxide as
      well as other features such as large-scale topography (see
      [POLLACKETAL1990]; [BARNESETAL1993]; and [HABERLEETAL1993]).
 
      The model has 25 latitude bins (7.5 degree resolution), 40
      longitude bins (9.0 degree resolution) and 13 vertical layers.
      The spacing between each layer varies.  The following array
      defines the layer spacing from the tropopause to the surface in
      mbars:
 
        0.005779, 0.009511, 0.01568, 0.02585, 0.04263, 0.07025,
        0.1159, 0.1544, 0.1586, 0.1364, 0.1223, 0.09270, 0.05000.
 
      The model spins up from a resting isothermal state with the
      global temperature equal to 200K.  The spin up starts with hour
      equal to 0.  The model saves data every 1.5 hours for a total
      of 16 hour bins per day.
 
      Some other initial conditions that are set when the model spins
      up:
 
      INITIAL SURFACE PRESSURE      : 7.60 mbars
      TROPOPAUSE PRESSURE           : 0.06699 mbars
      DUST OPTICAL DEPTH            : 0.3 (for periods where Ls < 200)
      DUST OPTICAL DEPTH            : 1.0 (for periods where Ls > 200)
      ICE CLOUD OPTICAL DEPTH       : 0.00
      TIME STEP                     : 9.25 minutes
      RICHARDSON NUMBER TIME SCALE  : 200000000. seconds
      SCALE HEIGHT FOR DUST PROFILE : 0.03000
      TIME CONSTANT FOR RAYLEIGH
        FRICTION                    : 2.0000 days
 
      This data set is composed of 20 to 30 day averages of the data
      resulting from model runs simulating martian conditions for
      four Ls periods during 1977 (Ls 10-24, 94-103, 202-220, and
      267-286).
 
        Native start time  =  10.15 AREOCENTRIC LON, EARTH YEAR 1977
        Native stop time   = 286.09 AREOCENTRIC LON, EARTH YEAR 1977
 
      The latitude-pressure data set contains the time and zonally
      averaged values for several first order, heating, eddy, phase
      and amplitude variables.  The data are given as a function of
      latitude and vertical pressure.  The calculations were done in
      the pi or uv coordinate system.  Pi coordinates are located at
      the intersection points of a set of evenly spaced latitude
      circles and a set of evenly spaced longitude circles.  UV grid
      points lie midway between PI grid points.  All data are given
      in the pi coordinate system.
 
      The data set is in the following configuration (listed as field
      followed by description):
 
      LATITUDE
        Latitude, degrees
 
      PRESSURE
        Vertical pressure coordinate, mbars
 
      WINDS_MER
        Meridional wind velocity, m/sec
 
      WINDS_VERT
        Vertical wind velocity, m/sec
 
      WINDS_ZON
        Zonal wind velocity, m/sec
 
      TEMP_VERT
        Vertical temperature profile, K
 
      MASS_STRM
        Mass stream function, kg/sec
 
      RES_MASS_STRM
        Residual mass stream function, kg/sec
 
      TOT_NET_HEAT
        Total net heating, K/day
 
      TOT_NET_ACC
        Total net acceleration, m/sec/day
 
 
      Diabatic heating parameters
      ---------------------------
      RAD_HEAT
        Radiative heating, K/day
 
      RF_HEAT
        Rayleigh friction heating, K/day
 
      SOL_HEAT
        Solar heating, K/day
 
      IR_HEAT
        Infrared heating, K/day
 
      15_MIC_HEAT
        15 micron band heating, K/day
 
      OUT_15_MIC_HEAT
        Outside 15 micron band heating, K/day
 
 
      Eddy variables
      --------------
      GEO_HT_VAR
        RMS geopotential height variance, m
 
      GEO_TEMP_VAR
        RMS geopotential temperature variance, K
 
 
      Phase and amplitude parameters
      ------------------------------
      TEMP_AMP_D
        Diurnal temperature amplitudes, K
 
      TEMP_AMP_SD
        Semi-diurnal temperature amplitudes, K
 
      TEMP_PHASE_D
        Diurnal temperature phase, hours
 
 
      TEMP_PHASE_SD
        Semi-diurnal temperature phase, hours

Confidence Level Overview
    =========================
      The Ames Mars General Circulation Model is a three dimensional
      computer model based upon the primitive equations of
      meteorology.  It includes the radiative effects of dust and
      carbon dioxide as well as other features such as large-scale
      topography.  Model results are dependent upon the selected
      initial conditions and spatial and temporal resolution of the
      model, and may not fully incorporate the effects of some
      physical processes represented by paramaterizations made by the
      model.